• Induction heating for brew kettle

    From Joerg@news@analogconsultants.com to rec.crafts.brewing on Wed May 22 16:17:15 2019
    From Newsgroup: rec.crafts.brewing

    Currently I am using two 1000W electric burners that my very wide
    13-gallon aluminum brew kettle straddles. They plug into two different circuits. My batches are 5-gallon and to make up for boil-off I start
    with slightly above 5-1/2 gallons. 70F to 155F takes a whole hour, 155F
    to 207F boil takes more than another hour.

    A few ideas a swirling around in my head on how to speed this up without investing a ton of money. One of them is to buy two 120V induction
    burners which come in 1800W, so more oomph. I'd probably set them to
    1500W in order not to overtax a circuit. Cost is about $50 a piece. Of
    course, the aluminum pot would not work by itself and here comes my
    first question:

    Does anyone know whether laying a big round steel disc inside the kettle
    would make this work efficiently? Considering the thickness of the
    aluminum bottom of the kettle the distance from the ceramic cooktop
    surfaces to that plate could exceed 1/8".

    Second question: If the power were the same how moch more efficient is induction heating versus regular electric burners in your experience?

    --
    Regards, Joerg

    http://www.analogconsultants.com/
    --- Synchronet 3.17c-Linux NewsLink 1.110
  • From Derek J Decker@derek@decker.net to rec.crafts.brewing on Thu May 23 15:28:30 2019
    From Newsgroup: rec.crafts.brewing

    On Wed, 22 May 2019 16:17:15 -0700, Joerg wrote:

    Currently I am using two 1000W electric burners that my very wide
    13-gallon aluminum brew kettle straddles. They plug into two different circuits. My batches are 5-gallon and to make up for boil-off I start
    with slightly above 5-1/2 gallons. 70F to 155F takes a whole hour, 155F
    to 207F boil takes more than another hour.

    A few ideas a swirling around in my head on how to speed this up without investing a ton of money. One of them is to buy two 120V induction
    burners which come in 1800W, so more oomph. I'd probably set them to
    1500W in order not to overtax a circuit. Cost is about $50 a piece. Of course, the aluminum pot would not work by itself and here comes my
    first question:

    Does anyone know whether laying a big round steel disc inside the kettle would make this work efficiently? Considering the thickness of the
    aluminum bottom of the kettle the distance from the ceramic cooktop
    surfaces to that plate could exceed 1/8".


    I purchased an induction burner a few months ago because it was on sale
    for $28 at Aldi - at that price, hey, new toy! And it works very well - certainly boiled water faster than my electric coils.

    But it didn't work with my copper-bottom Revereware pots, which limited
    what I could do with it. So I bought this:

    <https://www.amazon.com/gp/product/B07C2QTB3V/>

    which is basically a stainless steel disk with a handle, and is built precisely for this task. This goes under the pot you want to heat, and
    not inside it - induction makes the disk hot, which makes your pot hot,
    which boils the water. This is slightly less efficient than just
    directly heating a compatible pot, but still works well.

    My induction burner has two control methods - heat to a controlled temp,
    or run at a particular power. I can run the burner at its highest power
    with an induction-compatible pot of water on it.

    If I use the disk with a non-compatible pot at full power, the disc will overheat, and the burner will shut down till things cool off. The trick
    when using the disk is to set the burner to maintain the highest possible temperature (around 400°F is what I recall). This causes the burner to modulate its power output and not overheat. 'Course, you're putting less wattage into the pot than the burner could theoretically put out

    Of course, if you're running two 1800 Watt devices at once, you'll want
    them to be on separate circuits.

    summary:

    1) Steel disk works, is a standard product you can buy for this
    application

    2) Disk goes under the pot, not inside

    3) Disk reduces efficiency some, overheating may result


    Second question: If the power were the same how moch more efficient is induction heating versus regular electric burners in your experience?

    I could do controlled scientific experiments, but I haven't yet. I am of
    the opinion that a higher percentage of the heat generated by induction
    goes to the pot and not the surrounding air, etc

    -Derek
    --- Synchronet 3.17c-Linux NewsLink 1.110
  • From Joerg@news@analogconsultants.com to rec.crafts.brewing on Thu May 23 09:13:41 2019
    From Newsgroup: rec.crafts.brewing

    On 2019-05-23 08:28, Derek J Decker wrote:
    On Wed, 22 May 2019 16:17:15 -0700, Joerg wrote:

    Currently I am using two 1000W electric burners that my very wide
    13-gallon aluminum brew kettle straddles. They plug into two different
    circuits. My batches are 5-gallon and to make up for boil-off I start
    with slightly above 5-1/2 gallons. 70F to 155F takes a whole hour, 155F
    to 207F boil takes more than another hour.

    A few ideas a swirling around in my head on how to speed this up without
    investing a ton of money. One of them is to buy two 120V induction
    burners which come in 1800W, so more oomph. I'd probably set them to
    1500W in order not to overtax a circuit. Cost is about $50 a piece. Of
    course, the aluminum pot would not work by itself and here comes my
    first question:

    Does anyone know whether laying a big round steel disc inside the kettle
    would make this work efficiently? Considering the thickness of the
    aluminum bottom of the kettle the distance from the ceramic cooktop
    surfaces to that plate could exceed 1/8".


    I purchased an induction burner a few months ago because it was on sale
    for $28 at Aldi - at that price, hey, new toy! And it works very well - certainly boiled water faster than my electric coils.


    $28, wow! Unfortunately we don't have Aldi in Northern California.


    But it didn't work with my copper-bottom Revereware pots, which limited
    what I could do with it. So I bought this:

    <https://www.amazon.com/gp/product/B07C2QTB3V/>

    which is basically a stainless steel disk with a handle, and is built precisely for this task. This goes under the pot you want to heat, and
    not inside it - induction makes the disk hot, which makes your pot hot,
    which boils the water. This is slightly less efficient than just
    directly heating a compatible pot, but still works well.


    From what I've read on the Internet the "under the pot" transfer plates
    make things less efficient than the old electric coil cooktop because
    now you have two interfaces, induction coil to transfer disk, then
    transfer disk to bottom of pot. It won't matter much when cooking food
    in a smaller pot or pan but for the big brew kettle "watts into wort" is
    all that counts.


    My induction burner has two control methods - heat to a controlled temp,
    or run at a particular power. I can run the burner at its highest power
    with an induction-compatible pot of water on it.


    That would be the other issue I'd have to fix. Induction cooktops, for whatever weird reason, cannot be brought into a mode where the
    temperature can be set in 1F steps. They either have 40F steps or
    ocasionally 10F steps. If you have to hold 157F that's not going to
    work. Same for the fine line between rolling boil and boil-over. This is
    where my old $12 Walmart work well. They have a nice old analog
    thermostat knob where I put markers on the respective settings.
    Amazingly, that holds 157F to +/-2F precision, measured with an external sensor on a radio link.

    So I was thinking, if the temperature sensing happens via an NTC or PTC resistor under the ceramic layer I should be able to wire a
    potentiometer in series for vernier control. Of course, nicely insulated
    and all.

    The engineers could do it smarter like the ones for my thermostat did.
    When in normal mode it only offers five temps. Rare, medium-rare,
    medium, and so on. It's a meat thermometer for barbecue. However, when
    holding the temp-set button down for a few seconds it beeps, temp set
    goes into blink mode and then I can increment/decrement the temperature setting in 1F steps. Perfect to set the alarm for when I can put in my steeping grains.


    If I use the disk with a non-compatible pot at full power, the disc will overheat, and the burner will shut down till things cool off. The trick
    when using the disk is to set the burner to maintain the highest possible temperature (around 400°F is what I recall). This causes the burner to modulate its power output and not overheat. 'Course, you're putting less wattage into the pot than the burner could theoretically put out


    That would make steeping control tough and, more importantly, require me
    to be at the pot all the time later during the long initial boil.
    Currently I brew outside and when it's 40mins until the first flavoring
    hops go in I use that time to do some yard work, away from the pot, just
    not too far away. So far I only had one boil-over, a very messy affair,
    and that happened because I accidentally left the cooktops on max.


    Of course, if you're running two 1800 Watt devices at once, you'll want
    them to be on separate circuits.


    Oh yes, that's what I already do.


    summary:

    1) Steel disk works, is a standard product you can buy for this
    application

    2) Disk goes under the pot, not inside


    Many suggest a disk inside like here, for a more efficent heat tranfer:

    https://www.ebay.com/itm/Stainless-Steel-Cookware-Thermal-Guide-Plate-Induction-Cooktop-Converter-Disk/123517389767

    Yet I can't find any info on how much power you lose versus pot bottom thickness.

    I'd just need a much bigger disk and that I would have to cut myself.
    I'd have to find a place in the valley that carries sheet stock of
    stainless steel with enough magnetic property (IOW "the cheap stuff")
    and go there with a magnet in my pocket to test. Cleaning the brew
    kettle between brews would become more nasty though because first I'd
    have to fish a big dripping steel plate out of the remaining sludge. I
    could mount a small hook on it for that.


    3) Disk reduces efficiency some, overheating may result


    Second question: If the power were the same how moch more efficient is
    induction heating versus regular electric burners in your experience?

    I could do controlled scientific experiments, but I haven't yet. I am of
    the opinion that a higher percentage of the heat generated by induction
    goes to the pot and not the surrounding air, etc


    Just by gut feel, how much faster did it boil water that your electric
    coils?

    --
    Regards, Joerg

    http://www.analogconsultants.com/
    --- Synchronet 3.17c-Linux NewsLink 1.110
  • From Derek J Decker@derek@decker.net to rec.crafts.brewing on Thu May 23 17:06:32 2019
    From Newsgroup: rec.crafts.brewing

    On Thu, 23 May 2019 09:13:41 -0700, Joerg wrote:

    On 2019-05-23 08:28, Derek J Decker wrote:
    On Wed, 22 May 2019 16:17:15 -0700, Joerg wrote:

    Currently I am using two 1000W electric burners that my very wide
    13-gallon aluminum brew kettle straddles. They plug into two different
    circuits. My batches are 5-gallon and to make up for boil-off I start
    with slightly above 5-1/2 gallons. 70F to 155F takes a whole hour,
    155F to 207F boil takes more than another hour.

    A few ideas a swirling around in my head on how to speed this up
    without investing a ton of money. One of them is to buy two 120V
    induction burners which come in 1800W, so more oomph. I'd probably set
    them to 1500W in order not to overtax a circuit. Cost is about $50 a
    piece. Of course, the aluminum pot would not work by itself and here
    comes my first question:

    Does anyone know whether laying a big round steel disc inside the
    kettle would make this work efficiently? Considering the thickness of
    the aluminum bottom of the kettle the distance from the ceramic
    cooktop surfaces to that plate could exceed 1/8".


    I purchased an induction burner a few months ago because it was on sale
    for $28 at Aldi - at that price, hey, new toy! And it works very well -
    certainly boiled water faster than my electric coils.


    $28, wow! Unfortunately we don't have Aldi in Northern California.

    Aldi has good deals, but things that aren't food are not reliably stocked
    - you'd have to catch one by chance anyway.


    But it didn't work with my copper-bottom Revereware pots, which limited
    what I could do with it. So I bought this:

    <https://www.amazon.com/gp/product/B07C2QTB3V/>

    which is basically a stainless steel disk with a handle, and is built
    precisely for this task. This goes under the pot you want to heat, and
    not inside it - induction makes the disk hot, which makes your pot hot,
    which boils the water. This is slightly less efficient than just
    directly heating a compatible pot, but still works well.


    From what I've read on the Internet the "under the pot" transfer plates
    make things less efficient than the old electric coil cooktop because
    now you have two interfaces, induction coil to transfer disk, then
    transfer disk to bottom of pot. It won't matter much when cooking food
    in a smaller pot or pan but for the big brew kettle "watts into wort" is
    all that counts.

    Yeah, and that loss of efficiency is why the disk overheats for me. Much better to have an induction-ready brew kettle.



    My induction burner has two control methods - heat to a controlled
    temp, or run at a particular power. I can run the burner at its
    highest power with an induction-compatible pot of water on it.


    That would be the other issue I'd have to fix. Induction cooktops, for whatever weird reason, cannot be brought into a mode where the
    temperature can be set in 1F steps. They either have 40F steps or
    ocasionally 10F steps. If you have to hold 157F that's not going to
    work. Same for the fine line between rolling boil and boil-over. This is where my old $12 Walmart work well. They have a nice old analog
    thermostat knob where I put markers on the respective settings.
    Amazingly, that holds 157F to +/-2F precision, measured with an external sensor on a radio link.

    So I was thinking, if the temperature sensing happens via an NTC or PTC resistor under the ceramic layer I should be able to wire a
    potentiometer in series for vernier control. Of course, nicely insulated
    and all.

    The engineers could do it smarter like the ones for my thermostat did.
    When in normal mode it only offers five temps. Rare, medium-rare,
    medium, and so on. It's a meat thermometer for barbecue. However, when holding the temp-set button down for a few seconds it beeps, temp set
    goes into blink mode and then I can increment/decrement the temperature setting in 1F steps. Perfect to set the alarm for when I can put in my steeping grains.

    I think the inexpensive induction cooktops use bang-bang control. I
    recall some time ago thinking about induction for temp control during the mash, and I found a site where some guy had torn apart his induction
    burner, and found where to turn the thing on and off. He then arranged an external PID loop controller for controlling temperature.

    This is what you'd have to do - you want to control the temperature of
    the wort, not the burner. If you want your wort at 157°F, the burner
    will have to be slightly higher so that heat flows in to replace the heat
    flow off the top of the pot. How much higher would take some fiddling,
    it'd depend on the external temperatures...

    Also with bang-bang control the burner is either on at full power or off
    - so if you're running two, you should be sure your circuitry can handle
    both at full power.



    If I use the disk with a non-compatible pot at full power, the disc
    will overheat, and the burner will shut down till things cool off. The
    trick when using the disk is to set the burner to maintain the highest
    possible temperature (around 400°F is what I recall). This causes the
    burner to modulate its power output and not overheat. 'Course, you're
    putting less wattage into the pot than the burner could theoretically
    put out


    That would make steeping control tough and, more importantly, require me
    to be at the pot all the time later during the long initial boil.
    Currently I brew outside and when it's 40mins until the first flavoring
    hops go in I use that time to do some yard work, away from the pot, just
    not too far away. So far I only had one boil-over, a very messy affair,
    and that happened because I accidentally left the cooktops on max.


    Of course, if you're running two 1800 Watt devices at once, you'll want
    them to be on separate circuits.


    Oh yes, that's what I already do.


    summary:

    1) Steel disk works, is a standard product you can buy for this
    application

    2) Disk goes under the pot, not inside


    Many suggest a disk inside like here, for a more efficent heat tranfer:

    https://www.ebay.com/itm/Stainless-Steel-Cookware-Thermal-Guide-Plate-
    Induction-Cooktop-Converter-Disk/123517389767


    I haven't seen inside-the-pot plates, I note that the description for
    that one says it goes under the pot. I wonder about attenuation of the operating magnetic fields through the aluminum bottom.

    Yet I can't find any info on how much power you lose versus pot bottom thickness.

    I'd just need a much bigger disk and that I would have to cut myself.
    I'd have to find a place in the valley that carries sheet stock of
    stainless steel with enough magnetic property (IOW "the cheap stuff")
    and go there with a magnet in my pocket to test. Cleaning the brew
    kettle between brews would become more nasty though because first I'd
    have to fish a big dripping steel plate out of the remaining sludge. I
    could mount a small hook on it for that.


    3) Disk reduces efficiency some, overheating may result


    Second question: If the power were the same how moch more efficient is
    induction heating versus regular electric burners in your experience?

    I could do controlled scientific experiments, but I haven't yet. I am
    of the opinion that a higher percentage of the heat generated by
    induction goes to the pot and not the surrounding air, etc


    Just by gut feel, how much faster did it boil water that your electric
    coils?

    I have other things to do this afternoon, but I will stage a race and let
    you know later

    -Derek

    --- Synchronet 3.17c-Linux NewsLink 1.110
  • From Joerg@news@analogconsultants.com to rec.crafts.brewing on Thu May 23 10:38:42 2019
    From Newsgroup: rec.crafts.brewing

    On 2019-05-23 10:06, Derek J Decker wrote:
    On Thu, 23 May 2019 09:13:41 -0700, Joerg wrote:

    On 2019-05-23 08:28, Derek J Decker wrote:
    On Wed, 22 May 2019 16:17:15 -0700, Joerg wrote:

    Currently I am using two 1000W electric burners that my very wide
    13-gallon aluminum brew kettle straddles. They plug into two different >>>> circuits. My batches are 5-gallon and to make up for boil-off I start
    with slightly above 5-1/2 gallons. 70F to 155F takes a whole hour,
    155F to 207F boil takes more than another hour.

    A few ideas a swirling around in my head on how to speed this up
    without investing a ton of money. One of them is to buy two 120V
    induction burners which come in 1800W, so more oomph. I'd probably set >>>> them to 1500W in order not to overtax a circuit. Cost is about $50 a
    piece. Of course, the aluminum pot would not work by itself and here
    comes my first question:

    Does anyone know whether laying a big round steel disc inside the
    kettle would make this work efficiently? Considering the thickness of
    the aluminum bottom of the kettle the distance from the ceramic
    cooktop surfaces to that plate could exceed 1/8".


    I purchased an induction burner a few months ago because it was on sale
    for $28 at Aldi - at that price, hey, new toy! And it works very well -
    certainly boiled water faster than my electric coils.


    $28, wow! Unfortunately we don't have Aldi in Northern California.

    Aldi has good deals, but things that aren't food are not reliably stocked
    - you'd have to catch one by chance anyway.


    Out here in the west it's either Walmart or Amazon. Ikea has one for $49.


    But it didn't work with my copper-bottom Revereware pots, which limited
    what I could do with it. So I bought this:

    <https://www.amazon.com/gp/product/B07C2QTB3V/>

    which is basically a stainless steel disk with a handle, and is built
    precisely for this task. This goes under the pot you want to heat, and
    not inside it - induction makes the disk hot, which makes your pot hot,
    which boils the water. This is slightly less efficient than just
    directly heating a compatible pot, but still works well.


    From what I've read on the Internet the "under the pot" transfer plates
    make things less efficient than the old electric coil cooktop because
    now you have two interfaces, induction coil to transfer disk, then
    transfer disk to bottom of pot. It won't matter much when cooking food
    in a smaller pot or pan but for the big brew kettle "watts into wort" is
    all that counts.

    Yeah, and that loss of efficiency is why the disk overheats for me. Much better to have an induction-ready brew kettle.


    That gets expensive because I need a very wide kettle to straddle two cooktops. 13-gallon tamale steamers which is what I have now are
    generally aluminum.


    My induction burner has two control methods - heat to a controlled
    temp, or run at a particular power. I can run the burner at its
    highest power with an induction-compatible pot of water on it.


    That would be the other issue I'd have to fix. Induction cooktops, for
    whatever weird reason, cannot be brought into a mode where the
    temperature can be set in 1F steps. They either have 40F steps or
    ocasionally 10F steps. If you have to hold 157F that's not going to
    work. Same for the fine line between rolling boil and boil-over. This is
    where my old $12 Walmart work well. They have a nice old analog
    thermostat knob where I put markers on the respective settings.
    Amazingly, that holds 157F to +/-2F precision, measured with an external
    sensor on a radio link.

    So I was thinking, if the temperature sensing happens via an NTC or PTC
    resistor under the ceramic layer I should be able to wire a
    potentiometer in series for vernier control. Of course, nicely insulated
    and all.

    The engineers could do it smarter like the ones for my thermostat did.
    When in normal mode it only offers five temps. Rare, medium-rare,
    medium, and so on. It's a meat thermometer for barbecue. However, when
    holding the temp-set button down for a few seconds it beeps, temp set
    goes into blink mode and then I can increment/decrement the temperature
    setting in 1F steps. Perfect to set the alarm for when I can put in my
    steeping grains.

    I think the inexpensive induction cooktops use bang-bang control. I
    recall some time ago thinking about induction for temp control during the mash, and I found a site where some guy had torn apart his induction
    burner, and found where to turn the thing on and off. He then arranged an external PID loop controller for controlling temperature.


    That is a good idea.


    This is what you'd have to do - you want to control the temperature of
    the wort, not the burner. If you want your wort at 157°F, the burner
    will have to be slightly higher so that heat flows in to replace the heat flow off the top of the pot. How much higher would take some fiddling,
    it'd depend on the external temperatures...


    The old coil burner thermostats do that very nicely. I can turn one off
    and set the other to my steeping marker, then walk away for 1/2h. At the
    end it's usually still 156F, to within a couple of degrees. To my
    surprise even on a windy day when there is a lot of heat loss on the uninsulated aluminum pot.

    Same for the boil which can almost be run unattended.


    Also with bang-bang control the burner is either on at full power or off
    - so if you're running two, you should be sure your circuitry can handle
    both at full power.


    That's easy, just use opto-couplers and control both simultaneously.

    [...]


    summary:

    1) Steel disk works, is a standard product you can buy for this
    application

    2) Disk goes under the pot, not inside


    Many suggest a disk inside like here, for a more efficent heat tranfer:

    https://www.ebay.com/itm/Stainless-Steel-Cookware-Thermal-Guide-Plate-
    Induction-Cooktop-Converter-Disk/123517389767


    I haven't seen inside-the-pot plates, I note that the description for
    that one says it goes under the pot. I wonder about attenuation of the operating magnetic fields through the aluminum bottom.


    In the picture they show it inside the pot. Finding out about the
    attenuation is key, that's what I haven't figured out yet. Aluminum
    doesn't attenuate the field much but the added distance does.


    Yet I can't find any info on how much power you lose versus pot bottom
    thickness.

    I'd just need a much bigger disk and that I would have to cut myself.
    I'd have to find a place in the valley that carries sheet stock of
    stainless steel with enough magnetic property (IOW "the cheap stuff")
    and go there with a magnet in my pocket to test. Cleaning the brew
    kettle between brews would become more nasty though because first I'd
    have to fish a big dripping steel plate out of the remaining sludge. I
    could mount a small hook on it for that.


    3) Disk reduces efficiency some, overheating may result


    Second question: If the power were the same how moch more efficient is >>>> induction heating versus regular electric burners in your experience?

    I could do controlled scientific experiments, but I haven't yet. I am
    of the opinion that a higher percentage of the heat generated by
    induction goes to the pot and not the surrounding air, etc


    Just by gut feel, how much faster did it boil water that your electric
    coils?

    I have other things to do this afternoon, but I will stage a race and let
    you know later


    Great! This is all really longterm. The old coil burners work, it's just
    that making two beers plus clean-up takes all day that way. I turn on
    the cooktops when I get up at 6:30am, do some office work, put in the
    steeping grains at 7:30am, take a shower and so on, remove the grains at 8:00am and then walk the dogs while the wort heats up to boil. Rinse and repeat for the noon session.

    The real pain sets in when I have large late additions, for example
    another 3lbs of malt syrup. Unless I preheat that upstairs in the
    kitchen this requires another 20mins or so to get back to boil. Which
    can turn earlier flavoring hops partially into bittering hops.

    --
    Regards, Joerg

    http://www.analogconsultants.com/
    --- Synchronet 3.17c-Linux NewsLink 1.110
  • From Baloonon@baloonon@hootmali.com to rec.crafts.brewing on Fri May 24 00:14:26 2019
    From Newsgroup: rec.crafts.brewing

    Joerg <news@analogconsultants.com> wrote

    That would make steeping control tough and, more importantly, require
    me to be at the pot all the time later during the long initial boil. Currently I brew outside and when it's 40mins until the first
    flavoring hops go in I use that time to do some yard work, away from
    the pot, just not too far away. So far I only had one boil-over, a
    very messy affair, and that happened because I accidentally left the
    cooktops on max.

    If you're talking about steeping stuff like crystal malt, that typically
    can be done in a fraction of the water in something like a cooler or large thermos. If you're heating a lot of water, it ought to be possible to pull off, say, a couple of quarts at the lower steeping/mashing temperature,
    keep the grain/water mix in a thermos or cooler to maintain temperature,
    and by the time the water has come to a boil just add it back in to the
    main pot. Ovens are good for maintaining temps too if you're just talking about a half gallon or so.

    I'd have to find a place in the valley that carries sheet stock of
    stainless steel with enough magnetic property (IOW "the cheap stuff")
    and go there with a magnet in my pocket to test.

    You'd just want to make sure it's food grade if it's going inside the pot.
    --- Synchronet 3.17c-Linux NewsLink 1.110
  • From Joerg@news@analogconsultants.com to rec.crafts.brewing on Fri May 24 07:38:06 2019
    From Newsgroup: rec.crafts.brewing

    On 2019-05-23 17:14, Baloonon wrote:
    Joerg <news@analogconsultants.com> wrote

    That would make steeping control tough and, more importantly, require
    me to be at the pot all the time later during the long initial boil.
    Currently I brew outside and when it's 40mins until the first
    flavoring hops go in I use that time to do some yard work, away from
    the pot, just not too far away. So far I only had one boil-over, a
    very messy affair, and that happened because I accidentally left the
    cooktops on max.

    If you're talking about steeping stuff like crystal malt, that typically
    can be done in a fraction of the water in something like a cooler or large thermos. If you're heating a lot of water, it ought to be possible to pull off, say, a couple of quarts at the lower steeping/mashing temperature,
    keep the grain/water mix in a thermos or cooler to maintain temperature,
    and by the time the water has come to a boil just add it back in to the
    main pot. Ovens are good for maintaining temps too if you're just talking about a half gallon or so.


    I am a lowly extract brewer, mostly due to time constraints and even
    more so for lack of space. For many beers I have to steep in special
    grains, usually between 1/2lbs and 2lbs.

    My main thing is boil control though. The simple bi-metal thermostats on
    the cheap electric coil burners do that quite well. I'd just like to
    have more oomph than 2000W.


    I'd have to find a place in the valley that carries sheet stock of
    stainless steel with enough magnetic property (IOW "the cheap stuff")
    and go there with a magnet in my pocket to test.

    You'd just want to make sure it's food grade if it's going inside the pot.


    Good point. Though I am wondering whether my American but Made-in-China stainless steel fermenters are 100% kosher. There were the occasional
    rust spots and in the beginning I had to scrub out black polishing paste
    until no more came off. Though that also goes for lots of not very high-falutin pots and pans.

    --
    Regards, Joerg

    http://www.analogconsultants.com/
    --- Synchronet 3.17c-Linux NewsLink 1.110
  • From Derek J Decker@derek@decker.net to rec.crafts.brewing on Fri May 24 18:23:49 2019
    From Newsgroup: rec.crafts.brewing

    On Thu, 23 May 2019 10:38:42 -0700, Joerg wrote:

    On 2019-05-23 10:06, Derek J Decker wrote:

    I have other things to do this afternoon, but I will stage a race and
    let you know later


    Great! This is all really longterm. The old coil burners work, it's just
    that making two beers plus clean-up takes all day that way. I turn on
    the cooktops when I get up at 6:30am, do some office work, put in the steeping grains at 7:30am, take a shower and so on, remove the grains at 8:00am and then walk the dogs while the wort heats up to boil. Rinse and repeat for the noon session.

    The real pain sets in when I have large late additions, for example
    another 3lbs of malt syrup. Unless I preheat that upstairs in the
    kitchen this requires another 20mins or so to get back to boil. Which
    can turn earlier flavoring hops partially into bittering hops.

    OK, I did some experiments. All of these are times to bring 2 cups of
    water to a full rolling boil:

    6 inch burner, 1325 watts : 5:10
    8 inch burner, 2350 watts : 3:55

    1800 watt induction, compatible pot,
    full power : 2:10
    temp control at 464: 3:20

    1800 watt induction, incompatible pot,
    steel disc, control at 464: >12 minutes (I gave up)
    steel disc, full power: Unit overheats and shuts down

    Really, to get all the benefits of the induction burner, you need a
    compatible pot.

    Googling for 'induction homebrew', 'induction sous vide', and 'induction
    PID' brings up a number of interesting things. Cuisinart makes an
    induction burner that will pair with a bluetooth thermometer to control
    the fluid temp in a pot directly:

    <https://www.tastyonetop.com/>

    It's controlled by a smartphone app, and I hear the app stinks, but eh.

    There ya go

    -Derek

    --- Synchronet 3.17c-Linux NewsLink 1.110
  • From Joerg@news@analogconsultants.com to rec.crafts.brewing on Fri May 24 14:02:49 2019
    From Newsgroup: rec.crafts.brewing

    On 2019-05-24 11:23, Derek J Decker wrote:
    On Thu, 23 May 2019 10:38:42 -0700, Joerg wrote:

    On 2019-05-23 10:06, Derek J Decker wrote:

    I have other things to do this afternoon, but I will stage a race and
    let you know later


    Great! This is all really longterm. The old coil burners work, it's just
    that making two beers plus clean-up takes all day that way. I turn on
    the cooktops when I get up at 6:30am, do some office work, put in the
    steeping grains at 7:30am, take a shower and so on, remove the grains at
    8:00am and then walk the dogs while the wort heats up to boil. Rinse and
    repeat for the noon session.

    The real pain sets in when I have large late additions, for example
    another 3lbs of malt syrup. Unless I preheat that upstairs in the
    kitchen this requires another 20mins or so to get back to boil. Which
    can turn earlier flavoring hops partially into bittering hops.

    OK, I did some experiments. All of these are times to bring 2 cups of
    water to a full rolling boil:

    6 inch burner, 1325 watts : 5:10
    8 inch burner, 2350 watts : 3:55


    When interpolating that would come to about 4:30 if it was an 1800W burner.


    1800 watt induction, compatible pot,
    full power : 2:10
    temp control at 464: 3:20


    This is impressive. Assuming the above interpolated value that means
    about twice as fast. I wonder why it slowed down so much under temp
    control. Maybe the cooktop throttles down when it gets close.


    1800 watt induction, incompatible pot,
    steel disc, control at 464: >12 minutes (I gave up)
    steel disc, full power: Unit overheats and shuts down

    Really, to get all the benefits of the induction burner, you need a compatible pot.


    That's a problem because at reasonable cost there aren't any compatible
    pots wide enough to straddle two cooktops, only aluminum. A large steel
    dsik in there should work if the distance due to the thickness of the
    aluminum bottom isn't ruining the coupling.


    Googling for 'induction homebrew', 'induction sous vide', and 'induction
    PID' brings up a number of interesting things. Cuisinart makes an
    induction burner that will pair with a bluetooth thermometer to control
    the fluid temp in a pot directly:

    <https://www.tastyonetop.com/>

    It's controlled by a smartphone app, and I hear the app stinks, but eh.


    That is a good solution. They don't say whether temp control is in 1F increments but the video indicates it may be. I'd have to build a new thermistor probe because the furnished one is too tiny for a brew
    kettle. If it's just an NTC or PTC resistor probe that would be easy.

    Quite pricey at $149 but an option might be to use only one Cuisinart
    cooktops and then another regular one that isn't precisely controlled.
    The regular cooktop would be just to pump in power during heat-up. I can
    turn that off during steeping and reduce its power during the boil. One
    of them would have to get a spacer underneath to bring both to the same
    height but that is easy.

    It does have its quirks though.

    https://www.wired.com/review/tasty-one-top-smart-induction-cooktop/

    Quote "... the burner LEDs started blinking in the middle of a batch and clearly something was wrong, because the temperature started plummeting. Reading the FAQs later, I learned that this is a safety feature that
    kicks in if the cooktop is above 214 degrees Fahrenheit for more than 45 minutes; you just press the plus button on the One Top and keep
    cooking". That's an inconvenience for brewers. Hmm, maybe hacking a conventional induction cooktop is the better option.


    There ya go


    Thanks! Very helpful

    --
    Regards, Joerg

    http://www.analogconsultants.com/
    --- Synchronet 3.17c-Linux NewsLink 1.110
  • From Baloonon@baloonon@hootmali.com to rec.crafts.brewing on Fri May 24 22:00:08 2019
    From Newsgroup: rec.crafts.brewing

    Joerg <news@analogconsultants.com> wrote:

    On 2019-05-23 17:14, Baloonon wrote:

    Joerg <news@analogconsultants.com> wrote

    That would make steeping control tough and, more importantly,
    require me to be at the pot all the time later during the long
    initial boil. Currently I brew outside and when it's 40mins until
    the first flavoring hops go in I use that time to do some yard work,
    away from the pot, just not too far away. So far I only had one
    boil-over, a very messy affair, and that happened because I
    accidentally left the cooktops on max.

    If you're talking about steeping stuff like crystal malt, that
    typically can be done in a fraction of the water in something like a
    cooler or large thermos. If you're heating a lot of water, it ought
    to be possible to pull off, say, a couple of quarts at the lower
    steeping/mashing temperature, keep the grain/water mix in a thermos
    or cooler to maintain temperature, and by the time the water has come
    to a boil just add it back in to the main pot. Ovens are good for
    maintaining temps too if you're just talking about a half gallon or
    so.

    I am a lowly extract brewer, mostly due to time constraints and even
    more so for lack of space. For many beers I have to steep in special
    grains, usually between 1/2lbs and 2lbs.

    My main thing is boil control though. The simple bi-metal thermostats
    on the cheap electric coil burners do that quite well. I'd just like
    to have more oomph than 2000W.

    For what it's worth, to save some time and effort on brew day, steeping
    can be done in advance and the liquid can be stored in the fridge or
    even freezer. Obviously adding cold liquid will slow down the boil a
    bit, but if you're only talking 10% or less of the total amount of
    liquid, it shouldn't be too much.

    I'd have to find a place in the valley that carries sheet stock of
    stainless steel with enough magnetic property (IOW "the cheap
    stuff") and go there with a magnet in my pocket to test.

    You'd just want to make sure it's food grade if it's going inside the
    pot.

    Good point. Though I am wondering whether my American but
    Made-in-China stainless steel fermenters are 100% kosher. There were
    the occasional rust spots and in the beginning I had to scrub out
    black polishing paste until no more came off. Though that also goes
    for lots of not very high-falutin pots and pans.

    This looks like a pretty solid study on metals leaching out of stainless
    steel cookware, although I am definitely not qualified to interpret it
    in any detail.

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4284091/

    One thing I noticed though is that leaching tends to go down over time,
    so it's possible it's not something to worry about any longer....
    --- Synchronet 3.17c-Linux NewsLink 1.110
  • From Joerg@news@analogconsultants.com to rec.crafts.brewing on Fri May 24 15:18:06 2019
    From Newsgroup: rec.crafts.brewing

    On 2019-05-24 15:00, Baloonon wrote:
    Joerg <news@analogconsultants.com> wrote:

    On 2019-05-23 17:14, Baloonon wrote:

    Joerg <news@analogconsultants.com> wrote

    That would make steeping control tough and, more importantly,
    require me to be at the pot all the time later during the long
    initial boil. Currently I brew outside and when it's 40mins until
    the first flavoring hops go in I use that time to do some yard work,
    away from the pot, just not too far away. So far I only had one
    boil-over, a very messy affair, and that happened because I
    accidentally left the cooktops on max.

    If you're talking about steeping stuff like crystal malt, that
    typically can be done in a fraction of the water in something like a
    cooler or large thermos. If you're heating a lot of water, it ought
    to be possible to pull off, say, a couple of quarts at the lower
    steeping/mashing temperature, keep the grain/water mix in a thermos
    or cooler to maintain temperature, and by the time the water has come
    to a boil just add it back in to the main pot. Ovens are good for
    maintaining temps too if you're just talking about a half gallon or
    so.

    I am a lowly extract brewer, mostly due to time constraints and even
    more so for lack of space. For many beers I have to steep in special
    grains, usually between 1/2lbs and 2lbs.

    My main thing is boil control though. The simple bi-metal thermostats
    on the cheap electric coil burners do that quite well. I'd just like
    to have more oomph than 2000W.

    For what it's worth, to save some time and effort on brew day, steeping
    can be done in advance and the liquid can be stored in the fridge or
    even freezer. Obviously adding cold liquid will slow down the boil a
    bit, but if you're only talking 10% or less of the total amount of
    liquid, it shouldn't be too much.


    I could do that but it wouldn't save time, just move it to another day.
    Mostly I do not have that previous day available. I am trying to work
    other chores into brew day so the wait times can be occupied. Ok,
    occasionally watching a Western :-)


    I'd have to find a place in the valley that carries sheet stock of
    stainless steel with enough magnetic property (IOW "the cheap
    stuff") and go there with a magnet in my pocket to test.

    You'd just want to make sure it's food grade if it's going inside the
    pot.

    Good point. Though I am wondering whether my American but
    Made-in-China stainless steel fermenters are 100% kosher. There were
    the occasional rust spots and in the beginning I had to scrub out
    black polishing paste until no more came off. Though that also goes
    for lots of not very high-falutin pots and pans.

    This looks like a pretty solid study on metals leaching out of stainless steel cookware, although I am definitely not qualified to interpret it
    in any detail.

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4284091/

    One thing I noticed though is that leaching tends to go down over time,
    so it's possible it's not something to worry about any longer....


    Oh, oh, I should be dead by now ...

    I don't boil in the fermenters even though they are rated for that. Each
    has seen north of 40 brews so I guess it's all stabilized by now. I
    cleaned them very well before first use. The fermenters never get much
    rest, maximum one day.

    --
    Regards, Joerg

    http://www.analogconsultants.com/
    --- Synchronet 3.17c-Linux NewsLink 1.110
  • From Derek J Decker@derek@decker.net to rec.crafts.brewing on Fri May 24 23:11:01 2019
    From Newsgroup: rec.crafts.brewing

    On Fri, 24 May 2019 14:02:49 -0700, Joerg wrote:

    On 2019-05-24 11:23, Derek J Decker wrote:
    On Thu, 23 May 2019 10:38:42 -0700, Joerg wrote:

    On 2019-05-23 10:06, Derek J Decker wrote:



    6 inch burner, 1325 watts : 5:10
    8 inch burner, 2350 watts : 3:55


    When interpolating that would come to about 4:30 if it was an 1800W
    burner.


    1800 watt induction, compatible pot,
    full power : 2:10
    temp control at 464: 3:20


    This is impressive. Assuming the above interpolated value that means
    about twice as fast. I wonder why it slowed down so much under temp
    control. Maybe the cooktop throttles down when it gets close.

    The cooktop throttles down to keep the temp at 464. The entire disk (A steel-aluminum-steel sandwich) gets hot, but only part of it is covered
    by the pot. The thermal connection between the pot and disk isn't great
    - it's an older pot and a little wobbly on the very flat disk.

    I could fix all those things, but I'm not sure how much it would help.

    I did another experiment - I laid a sheet of aluminum foil on top of the inductive burner, then placed a inductive-compatible pot on top with some water. One layer of foil worked. Two layers of foil worked if I
    smoothed them together.

    4 layers of foil, though, made the burner complain there wasn't a
    compatible pot. YMMV.


    1800 watt induction, incompatible pot,
    steel disc, control at 464: >12 minutes (I gave up)
    steel disc, full power: Unit overheats and shuts down

    Really, to get all the benefits of the induction burner, you need a
    compatible pot.


    That's a problem because at reasonable cost there aren't any compatible
    pots wide enough to straddle two cooktops, only aluminum. A large steel
    dsik in there should work if the distance due to the thickness of the aluminum bottom isn't ruining the coupling.


    Granite wear, which is thin steel with a thin enamel layer, is compatible
    with induction burners, comes in large sizes, and is pretty cheap. It's usually black with white speckles.

    Granite wear is what I use for brew kettles here.

    Hmm, looking on their site, their biggest pot is a 33 quart crab/crawfish cooker. maybe not

    Googling for 'induction homebrew', 'induction sous vide', and
    'induction PID' brings up a number of interesting things. Cuisinart
    makes an induction burner that will pair with a bluetooth thermometer
    to control the fluid temp in a pot directly:

    <https://www.tastyonetop.com/>

    It's controlled by a smartphone app, and I hear the app stinks, but eh.


    That is a good solution. They don't say whether temp control is in 1F increments but the video indicates it may be. I'd have to build a new thermistor probe because the furnished one is too tiny for a brew
    kettle. If it's just an NTC or PTC resistor probe that would be easy.

    Quite pricey at $149 but an option might be to use only one Cuisinart cooktops and then another regular one that isn't precisely controlled.
    The regular cooktop would be just to pump in power during heat-up. I can
    turn that off during steeping and reduce its power during the boil. One
    of them would have to get a spacer underneath to bring both to the same height but that is easy.

    It does have its quirks though.

    https://www.wired.com/review/tasty-one-top-smart-induction-cooktop/

    Quote "... the burner LEDs started blinking in the middle of a batch and clearly something was wrong, because the temperature started plummeting. Reading the FAQs later, I learned that this is a safety feature that
    kicks in if the cooktop is above 214 degrees Fahrenheit for more than 45 minutes; you just press the plus button on the One Top and keep
    cooking". That's an inconvenience for brewers. Hmm, maybe hacking a conventional induction cooktop is the better option.


    Or (for a big pot) two inductive burners for moving temperature in the
    pot rapidly, and one electric with a cheap PID controller for maintaining
    mash temp, possibly maintaining boil. Cheaper, reliable, but you have to
    fit all those burners under there....


    There ya go


    Thanks! Very helpful

    --- Synchronet 3.17c-Linux NewsLink 1.110
  • From Joerg@news@analogconsultants.com to rec.crafts.brewing on Sat May 25 07:59:12 2019
    From Newsgroup: rec.crafts.brewing

    On 2019-05-24 16:11, Derek J Decker wrote:
    On Fri, 24 May 2019 14:02:49 -0700, Joerg wrote:

    On 2019-05-24 11:23, Derek J Decker wrote:
    On Thu, 23 May 2019 10:38:42 -0700, Joerg wrote:

    On 2019-05-23 10:06, Derek J Decker wrote:



    6 inch burner, 1325 watts : 5:10
    8 inch burner, 2350 watts : 3:55


    When interpolating that would come to about 4:30 if it was an 1800W
    burner.


    1800 watt induction, compatible pot,
    full power : 2:10
    temp control at 464: 3:20


    This is impressive. Assuming the above interpolated value that means
    about twice as fast. I wonder why it slowed down so much under temp
    control. Maybe the cooktop throttles down when it gets close.

    The cooktop throttles down to keep the temp at 464. The entire disk (A steel-aluminum-steel sandwich) gets hot, but only part of it is covered
    by the pot. The thermal connection between the pot and disk isn't great
    - it's an older pot and a little wobbly on the very flat disk.

    I could fix all those things, but I'm not sure how much it would help.

    I did another experiment - I laid a sheet of aluminum foil on top of the inductive burner, then placed a inductive-compatible pot on top with some water. One layer of foil worked. Two layers of foil worked if I
    smoothed them together.

    4 layers of foil, though, made the burner complain there wasn't a
    compatible pot. YMMV.


    Oh, that's bad news. Since the bottom of my pot is way thicker than four layers of foil it wouln't work with a disk inside.



    1800 watt induction, incompatible pot,
    steel disc, control at 464: >12 minutes (I gave up)
    steel disc, full power: Unit overheats and shuts down >>>
    Really, to get all the benefits of the induction burner, you need a
    compatible pot.


    That's a problem because at reasonable cost there aren't any compatible
    pots wide enough to straddle two cooktops, only aluminum. A large steel
    dsik in there should work if the distance due to the thickness of the
    aluminum bottom isn't ruining the coupling.


    Granite wear, which is thin steel with a thin enamel layer, is compatible with induction burners, comes in large sizes, and is pretty cheap. It's usually black with white speckles.


    Ah, the pots I saw in my grandparent's homes.


    Granite wear is what I use for brew kettles here.

    Hmm, looking on their site, their biggest pot is a 33 quart crab/crawfish cooker. maybe not


    That would not likely be wide enough. Width is the key to straddle two
    burners and just about the only way to brew with electrical power in the
    US. Unless you are willing to shell out big bucks for a restaurant grade
    240V cooktop and run a cable or install an immersion heater element in
    the brew pot. The latter would make it nearly impossible to stir in DME
    and is hard to clean. If DME clumps up on there it can make the beer
    taste funky.


    Googling for 'induction homebrew', 'induction sous vide', and
    'induction PID' brings up a number of interesting things. Cuisinart
    makes an induction burner that will pair with a bluetooth thermometer
    to control the fluid temp in a pot directly:

    <https://www.tastyonetop.com/>

    It's controlled by a smartphone app, and I hear the app stinks, but eh.


    That is a good solution. They don't say whether temp control is in 1F
    increments but the video indicates it may be. I'd have to build a new
    thermistor probe because the furnished one is too tiny for a brew
    kettle. If it's just an NTC or PTC resistor probe that would be easy.

    Quite pricey at $149 but an option might be to use only one Cuisinart
    cooktops and then another regular one that isn't precisely controlled.
    The regular cooktop would be just to pump in power during heat-up. I can
    turn that off during steeping and reduce its power during the boil. One
    of them would have to get a spacer underneath to bring both to the same
    height but that is easy.

    It does have its quirks though.

    https://www.wired.com/review/tasty-one-top-smart-induction-cooktop/

    Quote "... the burner LEDs started blinking in the middle of a batch and
    clearly something was wrong, because the temperature started plummeting.
    Reading the FAQs later, I learned that this is a safety feature that
    kicks in if the cooktop is above 214 degrees Fahrenheit for more than 45
    minutes; you just press the plus button on the One Top and keep
    cooking". That's an inconvenience for brewers. Hmm, maybe hacking a
    conventional induction cooktop is the better option.


    Or (for a big pot) two inductive burners for moving temperature in the
    pot rapidly, and one electric with a cheap PID controller for maintaining mash temp, possibly maintaining boil. Cheaper, reliable, but you have to
    fit all those burners under there....


    Induction burners are generally large. Even the regular ones are big and
    three won't fit. Of course, I could try to find a large ceramic plate
    from a discarded induction range (hard to find), cut it down and mount
    all the induction coils underneath in close proximity. That becomes a
    larger project though.

    --
    Regards, Joerg

    http://www.analogconsultants.com/
    --- Synchronet 3.17c-Linux NewsLink 1.110