Induction cook top heat control?

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AlZilla

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Greetings all,

A new guy here but no stranger to fermented libations. Here's hoping I haven't overlooked the answer to my question. It seems this forum is teeming with experts and experienced users of induction cook tops for our intended purpose.

I'm considering a 3500 watt induction cook top for my brewing and wondering about the ability to hold a given temperature for things like starch conversion. I'll be working up to about 8 or 9 gallons at a time, if that makes a difference. Weight capacity is some concern. I will be running a dedicated circuit if I go this route.

The Avantco IC3500 seems to be a very popular model. This unit, and the majority I've been able to research, allow temp control in 10 degree increments. 5 degree units are few and far between. I'm pretty certain that the set temp on the unit wouldn't be totally accurate but as long as I have the ability to make small changes I can zero in on a target temp. Lots of things in cooking require accurate temp control.

So, the question - can I hold, say 155F with the Avantco IC3500?

If not, can someone recommend a more suitable unit?

Thank you!
 

McKnuckle

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I have used the IC3500 for a number of years. It's a great asset to my brewery, convenient for heating water, mashing, and especially boiling. It's on a dedicated 240V circuit, so it leaves my single 110V circuit in the brewery free for normal stuff.

However, the unit does not accurately hold temperature to a numeric value despite settings that imply it will. If you insist on that, you'll be frustrated. What it does, though, is to very adequately hold a temperature range, certainly enough to survive a 60-90 minute mash. If you set it to 150F, for example, it may climb to 152 within 10 minutes - but that's a lot better than dropping. And it probably won't climb higher, either.

The performance you experience will be dependent on your mash volume and kettle size as well, different from mine - but the same limitations exist.

You can also do some interesting things like start your mash at 145F, set the cooktop to a very low setting, and allow the mash to slowly climb over an hour, moving through the entire beta/alpha amylase range into mash out.

If you insulate your mash kettle well, you can rely on stable temps for a 15-20 minute mash step, then recirculate and apply heat only to reach the next step. Turn off both and rest again at the new temperature.
 
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AlZilla

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Thanks, McKnuckle. No, I don't imagine 150 on the controller would actually be 150 in the kettle.

Some of the units seem to allow wattage control rather than temp. I'm not sure how finite I could control temp then, For example, tempering chocolate requires precise control. Not that I'm tempering chocolate but I'm wondering how precisely I could control temps with the 10 degree range so many of these induction tops offer.
 
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AlZilla

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I appreciate the benefit of your experience. Looks like this unit will do what I'd want it to do.
 

McKnuckle

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The more time I've spent with PID-driven temperature control - RIMS and kettle elements - the less I see it as absolutely critical and the more I see the utility in a simple induction cooktop.

Don't get me wrong - I don't mean that mash temp doesn't matter, far from it. I employ step mashes and mashouts nearly every time, and want that capability. It's just that dead nuts accuracy and stability are pretty elusive and is a target you can never really hit, since the mash is stratified anyway. The cooktop is "close enough" - it's mostly a mental OCD thing.

Unless you have programmable mash steps like some of the higher end systems, you have to enter those manually, requiring at least periodic checking in on the mash. That's not too different from how I described doing step mashing on the cooktop. Insulate the mash kettle. Apply heat and recirculate til you achieve the next step, then turn off the heat and pump and let it sit for the rest period. You can leave it alone during that time. I use a BBQ thermometer with Bluetooth so I can wander the house and check the temp with my phone.

The benefit is a simpler setup in the kettle, no element to clean, easier to use false bottoms and other gizmos without worrying about element clearance, etc.
 

jtgoral

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I am setting kettle temp + 10F in Avantco IC3500 and check with kettle termometer.
 

Consigliere

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I use induction cooktop stove with 3700
Burner. I can keep mash temp within 1F for 60-90 min using my recirc
Pump flow and burner output as the controls. I have insulated kettle as well. 9/10 I set the induction output constant and slightly adjust recirc flow -
Lower flow keeps heat in and higher flow loses it. My setup based on what I have to use. I brew 5G batches so usually mash with about 7G or strike water.
 
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AlZilla

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I use induction cooktop stove with 3700
Burner. I can keep mash temp within 1F for 60-90 min using my recirc
Pump flow and burner output as the controls. I have insulated kettle as well. 9/10 I set the induction output constant and slightly adjust recirc flow -
Lower flow keeps heat in and higher flow loses it. My setup based on what I have to use. I brew 5G batches so usually mash with about 7G or strike water.
1 degree is awesome. What is a "3700 burner"?
 

Consigliere

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Sorry I have a Bosch induction cooktop for my home stove and it has a 3700 w burner in it that I use for brewing. So in my kitchen. Wife loves it!
 
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AlZilla

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Sorry I have a Bosch induction cooktop for my home stove and it has a 3700 w burner in it that I use for brewing. So in my kitchen. Wife loves it!
I got it. Does the Bosch adjust in 5 or 10 degree increments?

Thanks,
 

jerrylotto

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My biggest concern about these things is weight. I use a 20 gal pot and often have 15 gal in it at a time. My propane burner and my gas stove are both built to handle that kind of weight but is there a portable induction unit that I could trust?
 

McKnuckle

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Depending on the diameter of the kettle base, you can set it upon blocks that flank the cooktop, so that its weight is not held by the cooktop itself. It doesn't have to touch the cooktop, it just has to be very close in order for the magnets to work.

Have a look at what this fellow did.
 

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cbier60

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My biggest concern about these things is weight. I use a 20 gal pot and often have 15 gal in it at a time. My propane burner and my gas stove are both built to handle that kind of weight but is there a portable induction unit that I could trust?
I have been using an Avantco IC3500 with my 20G Spike kettle for 4.5 years. The outside kettle diameter is ~18", so it sits on the outer frame of the IC3500. There is no problem with the weight nor getting the heat into the kettle.
 

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I have been using an Avantco IC3500 with my 20G Spike kettle for 4.5 years. The outside kettle diameter is ~18", so it sits on the outer frame of the IC3500. There is no problem with the weight nor getting the heat into the kettle.
Exactly, I have the same experience. Although I usually use an 8 gallon kettle, I also use a 17" diameter 15 gallon kettle for larger batches, full, with no problem. It overhangs the frame by several inches all around.

But that same 8 gallon kettle on my glass top stove top [Edit] (conventional radiant coil heating) always scared me due to the sheer weight. Besides, the stove top's largest (triple) burner could not boil it very well unless I had the lid on most of the way. It kept cycling on and off. :drunk:
That's why I bought the IC3500, and never looked back.
 
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cbier60

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Besides, the stove top's largest (triple) burner could not boil it very well unless I had the lid on most of the way. It kept cycling on and off. :drunk:
That's why I bought the IC3500, and never looked back.
My lid is almost always on. I have been using the IC3500 for 4.5 years as mentioned above, and have added a boil condenser for the last 3. Simple DIY BIAB indoor electric brewing. I have no interest in expanding to a 3V system.
 
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Greetings,

I was looking at 1800w and 3500w induction cooktops. There is a significant price difference between the two so I was wondering a couple things that I haven't found in other threads.

1a. Is this mostly for BIAB, so one cooktop only?
1b. If someone is using multiple vessels, do you use multiple burners or move the kettles around?

2a. With 3500w, how long to get 70F H2O to 165F, and then 152F wort to 212F?
2b. With 1800w, how long to get 70F H2O to 165F, and then 152F wort to 212F?

If there is a website/thread that I missed, I am happy if you want to just drop a link; I just want to know if moving from propane to induction is the right move for me.

Peace,

Reevesie
 

IslandLizard

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I was looking at 1800w and 3500w induction cooktops. There is a significant price difference between the two so I was wondering a couple things that I haven't found in other threads.
Sure, there is a significant difference in price.
An 1800W (120V) induction plate can be had for as low as $20-50. Some (more) commercial grade ones for $80-150, and up.
Some (consumer/TV) brands may come with (needless) gadgets, not shoring up the quality of the unit.

A 3500W (240V) induction plate can be had for $180 (e.g., Avantco IC3500).
There will be some extra cost involved getting it operational, since they also require a 240V socket (receptacle) that can deliver 15A (minimally) or 20A.
An existing 30A or 50A circuit can be used if you change out the unit's plug or the socket. Or buy or make an adapter cord.


2a. With 3500w, how long to get 70F H2O to 165F, and then 152F wort to 212F?
I've never timed it exactly, but 5 gallons of (strike) water can be heated to 165-170F in 20-30 minutes I'd say. I'll time it next time.

2b. With 1800w, how long to get 70F H2O to 165F, and then 152F wort to 212F?
About twice as long as 3500W.

In either case, but more so with the 1800W unit, it helps putting some insulation around the kettle (e.g., Reflectix, bubble wrap, thick towels). Also put a lid on the kettle and cover that with a triple folded over thick towel. Anything to reduce heat loss.
 
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Thank you! I have a 240 receptacle, it's used for the air compressor and welder-which is to say, not very often as we aren't doing as much sheet metal work anymore. Powering a 3500w induction burner seems like a good repurposing of that resource. I have heard a double layer of reflectix works great for insulation. I am thinking this is doable, I guess I just need to decide if I go back to BIAB with one burner or get two burners for 3V brewing or move whichever kettle needs to be heated onto the one burner (the least fun choice).

As my driveway is the wind vortex of the alleyway, where everyone's dust and leaves end up, I would really like to be able to brew without having to filter out non-brew related material. Being able to brew with the garage door closed through most of the process would also be a bonus on those windy days when the flame is bent sideways, heating anything but the kettle.
 

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Thank you! I have a 240 receptacle, it's used for the air compressor and welder-which is to say, not very often as we aren't doing as much sheet metal work anymore. Powering a 3500w induction burner seems like a good repurposing of that resource. I have heard a double layer of reflectix works great for insulation. I am thinking this is doable, I guess I just need to decide if I go back to BIAB with one burner or get two burners for 3V brewing or move whichever kettle needs to be heated onto the one burner (the least fun choice).

As my driveway is the wind vortex of the alleyway, where everyone's dust and leaves end up, I would really like to be able to brew without having to filter out non-brew related material. Being able to brew with the garage door closed through most of the process would also be a bonus on those windy days when the flame is bent sideways, heating anything but the kettle.
I've made some small edits to my post, but the essence is the same.

I use a converted cooler as mash/lauter tun, and mash at 1.5 qt/lb. After complete draining, batch sparged 2x with equal volumes. First runnings are heated as soon as I lautered 1-2 gallons, and more added as they accumulate, same for 2nd and third runnings. By the time I add the last partial gallon the whole 7 gallons is already boiling, or nearly.

Whenever step mashes are needed (not often), they're done in the boil kettle under constant stirring while heating directly. A triple ply bottom also prevents scorching, and special attention is paid to the 6" "hotspot disk" in the center of the kettle. When finished it gets heated to mashout temps and transferred to the cooler for lautering and sparging.
 

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A 3500W (240V) induction plate can be had for $180 (e.g., Avantco IC3500).
Note the Avantco IC3500 specs indicate a maximum pan diameter of 10.25". What pot diameter(s) do brewers successfully use with this induction plate?

My 8 gallon Bayou Classic kettle is ~12" diameter. There is a suggested weight capacity of 65 lbs, which implies roughly a ~8 gallon maximum initial boil volume. So that is more than enough for a 5.5 gallon (in the fermenter) recipe. So I assume my kettle would work ok, even though the diameter is greater than the specified maximum pan diameter?

Edit: My Bayou Classic kettle bottom is magnetic, but not the sides.
 
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IslandLizard

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Note the Avantco IC3500 specs indicate a maximum pan diameter of 10.25". What pot diameter(s) do brewers successfully use with this induction plate?
That spec means nothing. Not even sure why it's even mentioned, as it doesn't matter one iota to the plate's functionality.
The induction coil heats a circular area in your induction capable pot/kettle/griddle. That area is around 6" in diameter, smack above the center of the coil, indicated on the glass plate.

The IC3500 has a stainless steel frame. It's very sturdy and can hold a lot of weight.

I have an 8 gallon 14" diameter boil kettle, it pretty much overhangs the whole unit, only leaving a small bit of the very corners exposed. Also a 15 gallon, 17" diameter kettle. No issues with either kettle, with years of good service, not just used for brewing.
 

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Edit: My Bayou Classic kettle bottom is magnetic, but not the sides.
Wow, that's strange! Is there a visible seam or weld where they meet?

One of my "spares" is a fairly lightweight, non-magnetic Polar Ware kettle. But she works like a charm on an induction plate. Just gotta watch out for potential scorching in that 6" heated circle area, as it has a fairly thin, single ply bottom.

I use it to heat and keep sparge water in, also for boiling large batches of soup and stock.;)
 

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I have an IC3500. I use a 10 gallon kettle with a 13” diameter with no problems. In face I prefer that the kettle overhangs to the metal frame; that’s taking a lot of the weight rather than a glass top.
I’ll get strike to mash temp in 20 minutes or so, depending on the starting temp and temp in my basement. Mash out to boil is under -5 minutes, and even faster if I have it at full tilt - I have to time carefully for my spare - I want to have it just getting to boil temp as the sparse finishes - that much less to bring up to temp later.
As far as ventilation, I keep an exhaust fan going in the window over my brew area, and the door cracked open to help the draft.
With the 3500, brewing 5.5 gallon batches, I don’t have to worry about insulation. It’s quick enough already. I do use a cooler mash tun.

editing to add: if you're planning on BIAB, you may need to consider insulation. The thing about induction burners is that the element is on or off, you have vague adjustments via the wattage setting, which is more how fast the element turns on and off. You can't adjust the temp like you can a traditional electric burner or certainly gas. But water (and the mash) has a lot of thermal mass; it takes a lot to change temp. You might experiment a bit with plain water, see how long it takes to drop an amount of temp in a given time\, and see if that works out for you - a couple degrees over the time of mash is fine, but more that say, 5 degrees drop over the hour probably isn't good.
 
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Barbarossa

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Also a 15 gallon, 17" diameter kettle. No issues with either kettle, with years of good service, not just used for brewing.
I assume that's what you meant, but can your unit hold the weight of the the 15 gallon full of wort? That's would be 140 pounds, roughly. Can it heat up and boil properly that amount?
 

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I assume that's what you meant, but can your unit hold the weight of the the 15 gallon full of wort? That's would be 140 pounds, roughly. Can it heat up and boil properly that amount?
Yes, it holds that weight of a full 15 gallon kettle with no issues. As @jrgtr42 said, mainly because it's supported by the stainless frame of the unit. There's also the 1mm (?) thick base plate into which the feet are screwed in on the corners. The tempered heat resistant glass plate over the coil is just an inlay in that frame.

Now at a maximum output of 3500W it takes twice as long to heat and boil a 10 gallon batch as it takes a 5 gallon one. Adding some insulation becomes almost paramount, but I've run it fine without it.
You could get a 2nd plate (and kettle) to help heat your water/wort. When boiling, combine into the one (primary) kettle.
I wish I had wired in that second 240V circuit/outlet next to it, while I had the countertop off. ;)

@brewman ! built a 5000W induction plate to overcome the "limitations" of 3500W while not spending $500+ on a commercial unit:
 

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I'm just climbing out of the rabbit hole of trying to come up with a solid induction solution. I wanted to control it with a PID, so I bought an Adcraft induction burner that has a manual control so that when powered, it can resume at the power level it was at when it lost power.

I though I could control it with a PID and just cycle power off/on as needed via the plug. In theory it works as designed, but the unit does not like having it's power cycled off and on. It has a cooling fan that, of course, also shuts off when the power goes off and, in short order, it goes wonky and stops working.

Just a week ago I gave up. This has been a 2 year project, starting with an Auber Cube, then CraftBeerPi and a bunch of custom cabling to make them all work together. My crazy idea all works except for the induction burner. I finally said "screw it" and ordered a new ekettle from Spike.

It would be really cool if someone made an induction burner with built in temp control that was based on an external sensor, but there's no such beast that I can find. You'd think that someone would make a purpose-built unit for brewing, but I suspect it's cost prohibitive.

If you are doing simple non-recirc eBIAB, some other rig that doesn't require PID control, induction works great. If you don't care about mash temps being fairly precise, it sounds like that's an option (based on comments above), but those didn't fit what I was trying to do.

I should have my K-RIMS rig up and running very quickly after my new eKettle arrives. I can drop the cobbled together cube/CraftBeerPi controller too.
 
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Is anyone running two induction burners (not at the same time) but one for HLT and one for BK? MT in between? I am not sure I want to spend ~$400 on two, but I'm also not sure I want to lift an HLT w/ 7G up to table height, and then when empty, slide it over and lift a BK w/6.5G onto the burner. I'm strong enough now, but that's going to get real old, real fast.
 

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I'm also not sure I want to lift an HLT w/ 7G up to table height, and then when empty, slide it over and lift a BK w/6.5G onto the burner. I'm strong enough now, but that's going to get real old, real fast.
Not only because they're heavy, it's awkward (and bad for your body) to lift up to that height.
Years ago I sprang a small abdominal hernia lifting a nearly full 15 gallon kettle 4" up onto the induction plate, and that was on a knee-height bench. I had it checked out, it wasn't too bad, but I can still feel it sometimes...
 
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Is anyone running two induction burners (not at the same time) but one for HLT and one for BK? MT in between?
That's actually not a bad idea. It prevents having to lift or move (heavy) full kettles. Just power the plate you need to use.

If the receptacle is on a 30 Amp circuit, you can power both plates at the same time. Each pulls around 13.5 Amps, from what I've read somewhere (so they are not quite 3500W either). I don't have the meter or a shunt to measure that high of a current.
 
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That's actually not a bad idea. It prevents having to lift or move (heavy) full kettles. Just power the plate you need to use.

If the receptacle is on a 30 Amp circuit, you can power both plates at the same time. Each pulls around 13.5 Amps, from what I've read somewhere (so they are not quite 3500W either). I don't have the meter or a shunt to measure that high of a current.
That is exactly the info I needed to know! Thank you! Time to start saving!
 

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That is exactly the info I needed to know! Thank you! Time to start saving!
It's not a terribly big outlay. In the past they've sometimes run specials on them. Plus you have a backup, just in case...

Note on the fan:
Not saying every IC3500 has this problem, I haven't seen any other reports on it. It may well be a very isolated issue, a fluke, and just a bad fan from that time period.

The first IC3500 I bought (anno 2013) developed a fan problem after a couple years of regular use, both for brewing and some general use in the kitchen, such as cooking, soups, stews, stocks, wokking, etc. The fan started to slow down, you could clearly hear it drag/surge. The shaft (in a sleeve bearing) needed to be cleaned and a drop of oil, that fixed it. I've been doing that about every year of use, since then. The fan, at least in that particular in that unit, is fairly crappy and cheaply made. Definitely a weak link, but I haven't found a replacement for it. It has a 2-point mounting bracket and is different from an average computer type fan.

The good news is, the 2nd IC3500 unit I bought hasn't shown that problem, at least as of yet. It has been getting regular, almost daily use the past 2-3 years. So we're keeping those fingers crossed.

If used solely for brewing, say for 10-20 batches a year, one may never encounter any issues with the fan, if there is one at all.
 

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Is anyone running two induction burners (not at the same time) but one for HLT and one for BK? MT in between? I am not sure I want to spend ~$400 on two, but I'm also not sure I want to lift an HLT w/ 7G up to table height, and then when empty, slide it over and lift a BK w/6.5G onto the burner. I'm strong enough now, but that's going to get real old, real fast.
I use an Avantco 3500 for strike water heating, then pump it to a cooler mash tun. While mashing, I heat sparge water with a cheap 1800w induction burner..gets about 5 gallons to 180F well before mash hour is up.
 

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