Can I put my BIAB directly on the heating element?

[specialkayme]

I do single infusion, single vessel eBIAB, with a mesh bag, a 5500 ULWD heating element and a dragonstill controller. I typically get my strike temp, kill the element, mash in, and wrap the kettle in a sleeping bag.

Despite my best efforts, I still end up losing 8-12 degrees per hour during mashing on average (depending on the time of year). I'm looking to get a little bit more control over mash temps and keep it a little more consistent. More insulation seems like a pain.

Would it be possible to heat my strike temp, kill the element, mash in, then turn the heating element onto something like 5% power, just enough to reduce some of the heat loss?

I haven't tried it yet, for fear of losing a bag and/or a heating element. I know if I crank the element up I'll burn the bag. But at something like 5%, with a ULWD element, can I get away with it? I heard you can put a nylon bag directly on the SS Brewtech halo element without burning it, and I'm not sure if it's a special element, special controller, or something else that enables you to do that.

 

[Carolina_Matt]

This doesn't answer your question, but I'm surprised you're losing that much temperature. I'm also in North Carolina, and I did my first three BIAB batches this month. I did them in my garage where it's probably been about 50 degrees or so. I think I lost 3-4 degrees in each of my batches. The first time, I just draped a moving blanket over it. The last two times, I put a rope around the moving blanket to keep it pressed against the kettle.

Are you wrapping the sleeping bag around just the sides, or covering the top of the kettle also?

 

[hezagenius]

Can you fit a false bottom on top of your element? That's what I do. I have a ripple ULWD 5500W element and put a false bottom on top of it to keep the bag of the element during the mash. I recirculate during the mash and it holds the temp within +/- 1F.

 

[McKnuckle]

I have a 14" diameter kettle wrapped with one layer of Reflectix insulation (lid also). I use a mash cap which is a disk I made from 1" thick hard foam insulation. I place that in the kettle right over the mash to reduce headspace. Then I wrap the whole thing in a blanket. The room is quite warm at 75F (it's in my basement where the boiler is).

I still lose 4 degrees per hour. I find that perfectly acceptable, but I agree that heat retention is challenging. Some people seem to have no issue with it.

 

[Warren Boese]

I have the exact same set up as you, here's what I've been doing. Mash in, my kettle sits on a large folded up beach towel to reduce losses out the bottom, put lid on, wrap entire kettle with sleeping bag. It'll sit at mash temp for 1/2 hour and drop 1 or maybe 2 degrees, then remove sleeping bag and hoist up the mash bag till just off element. Fire element, stir well and bring wort back to temp, shut off element, lower bag and re insulate. Good for another half hour. I've let the bag partially contact the element, petty sure, and all was ok. Next brew I'm gonna leave it in loose and fire the burner half power and see what happens.
Get your kettle bottom insulated if you haven't yet!

 

[specialkayme]

Yeah, all sides are insullated.

Actually, before I fill the kettle up with water, I put the sleeping bag down on the table it will all rest on, then I put a large wooden cutting board down, and then the kettle. I fill the kettle with the appropriate amount of water, heat it up, kill the element, drop the bag in, dough in, then put the lid on and pull the sleeping bag up and over the kettle and hold it all in place with small clamps. ALL sides of the kettle are wrapped up in the sleeping bag (and the bottom is sitting on a wooden block that is included in the sleeping bag as well).

The last 4 batches had the following heat losses:
1/20 - 15 degrees over 90 min (10 per hour)
12/10 - 12 degrees over 60 min (12 per hour)
11/18 - 8 degrees over 60 min (8 per hour)
11/11 - 7 degrees over 60 min (7 per hour)

Average - 9.25 degrees per hour

I didn't include the "half batches" (that produced 2.5 gals, and were done in a smaller pot), because the thermodynamics are entirely different even though the sleeping bag is the same Although in case you were wondering they had losses of between 4 and 6 degrees per hour.

I thought about doing some reflectix in addition to the sleeping bag, but I'm starting to not feel comfortable with all the "bandaids." I don't even like the sleeping bag, but can live with it. Reflectix with a sleeping bag seems excessive.

I haven't looked into a false bottom yet, in part due to the cost and in part due to the difficulty. My kettle was custom made from Spike (and I love it by the way) but there isn't an easy off the shelf solution to getting a false bottom that fits. So I'd have to have one custom made. Which gets a little pricey. And if I"m going to do that, I mine as well have a custom basket made instead of a false bottom, and at that point I'm violating my KISS principle.

 

[LittleRiver]

... get my strike temp, kill the element, mash in, and wrap the kettle in a sleeping bag....end up losing 8-12 degrees per hour....

That is way more heat loss than I see using a similar process. Several times I've stayed within 1deg for the entire hour. I always stay within 1deg for the critical first 15-20 minutes, by which time conversion is complete anyway (with a .025" crush).

Is your kettle sitting on something that is conducting heat away, or is the bottom of the kettle elevated and open to the air which could draw away heat? Are you just throwing the sleeping bag over the kettle, or are you wrapping it carefully?

[Edit: your post explaining your process was made after I started editing mine, so I didn't see it before I posted.]

 

[specialkayme]

I have the exact same set up as you, here's what I've been doing. Mash in, my kettle sits on a large folded up beach towel to reduce losses out the bottom, put lid on, wrap entire kettle with sleeping bag. It'll sit at mash temp for 1/2 hour and drop 1 or maybe 2 degrees, then remove sleeping bag and hoist up the mash bag till just off element. Fire element, stir well and bring wort back to temp, shut off element, lower bag and re insulate. Good for another half hour.

I brew in my kitchen, and have to drag out a ladder and put it up over the kettle in order to lift the bag out. It's a pain. I don't like doing it once per brew, but do anyway. Twice per brew seems like a nightmare.

I've let the bag partially contact the element, petty sure, and all was ok. Next brew I'm gonna leave it in loose and fire the burner half power and see what happens.

I'd be interested in knowing what happens, if you don't mind.

I'm contemplating just going to buy a small scrap of nylon and doing a test with some water. At that point I wouldn't lose my brew bag if things go bad. I may lose the heating element, which isn't great, but at least I'd get my answer.

 

[specialkayme]

Is your kettle sitting on something that is conducting heat away, or is the bottom of the kettle elevated and open to the air which could draw away heat? Are you just throwing the sleeping bag over the kettle, or are you wrapping it carefully?

I think our posts "passed like ships in the night." Check out post #6 if you can, I think it has your answer.

 

[harry_the_face]

Do you use a strike water calculator to determine your strike temp? Is the mash temp at the desired temp when you start? How are you taking the temp before and after? Just want to eliminate assumptions.

 

[specialkayme]

Do you use a strike water calculator to determine your strike temp?

Yes - from brewer's friend (although it isn't always perfectly accurate, it's usually under by about 4 degrees, so I heat 4 degrees higher, but that's probably more to do with my grain temp than the calculator)

Is the mash temp at the desired temp when you start?

Usually

It's actually a kinda hard question to answer. If I want to mash in at 150, I can set my strike water to hit at 161 which will give me an initial mash at 150. But if I'm going to lose 10 degrees over an hour, I can't finish at 140 and produce the same beer than if I maintained temps at a closer range to 150. So I strike higher than my "desired" temp, in order to maintain more appropriate mash temps over the entire 60 min. So I'll usually shoot for a mash of 153, knowing I'll drop down to 148-142 over the next hour.

I still make good beer. Well, beer I like at least. Which is fine. But it makes it difficult to repeat the process, and difficult to alter the recipe slightly, if I lose anywhere between 7 and 12 degrees in an hour.

How are you taking the temp before and after?

With a javalin thermometer, stuck in the center of the water, dead center, as far down as the probe will go before I get "plastic wet".

I use the same method to measure my strike water, the temp at the start of mash, and the temp at the end of mash.

I used to take temp readings every 15 minutes during the mash, but found the loss was pretty close to linear, and I was only losing heat by opening up the sleeping bag, so stopped. Ironically I opened the kettle at the 30 minuite mark on the 11/11 batch, which ended up producing the least heat loss of the last 4 batches. I didn't open up the other 3 at all during the entire mash.

Just want to eliminate assumptions.

Sure. No worries. I appreciate the thoroughness of your questions and attempts to help!

 

[Warren Boese]

Ok I'll let ya know, I use the same bag material, only small size, loose in the kettle for my hops and they are all over the element during the boil so think it'll be ok, hopefully!!

 

[LittleRiver]

Are you opening up the insulation one or more times to check temp or stir during the mash? If so, you are losing a lot of heat each time. If not, I am stumped by your heat loss readings.

If anything you are insulating better than I do. I insulate like this. I don't open the insulation during the mash. I never have a problem with heat loss.

The thermal mass of my burner is inside the insulation, which will give off some residual heat, which will be a difference between my setup and yours.

 

[specialkayme]

Are you opening up the insulation one or more times to check temp or stir during the mash?

1/20, 12/10, and 11/18's brews were not opened. Just took the temp before and after the mash. Kept it wrapped up tight inbetween.

11/11's brew I did open it once at the 30 min mark to check the temp. Ironically it was the one that had the least heat loss (but it was also the warmest that day).

 

[Carolina_Matt]

With a javalin thermometer, stuck in the center of the water, dead center, as far down as the probe will go before I get "plastic wet".

Have you tried taking the temperature at the top of the water, closer to the surface? I wonder if you're putting it down into the grains, and that's impacting the reading somehow?

 

[sublxed]

For under 50 bucks get yourself a sous vide stick. It will circ your mash and keep your temp

 

[specialkayme]

Have you tried taking the temperature at the top of the water, closer to the surface?

The javalin probe is only 3" long. There won't be much of a difference between there and the surface. At least there hasn't been when I measured in the past.

 

[LittleRiver]

...brews were not opened. Just took the temp before and after the mash. Kept it wrapped up tight inbetween...

I'm stumped.

What is the sleeping bag? Is it a thin single layer of fleece, or a thick quilted one with synthetic or down insulation?

 

[specialkayme]

It's a northface backpacking sleeping bag. I used to have two when I went camping. One lighter one for summer months, and one thicker one for fall or spring months. It's the thicker one. I don't know what it's rated for though.

 

[harry_the_face]

I am stumped by the heat loss too but here are a few ideas:
If your pot is aluminum it will lose much more heat than stainless and could account for the increase.

Heat rises so the top of the mash will usually be warmer than the bottom. If you are getting the same temp throughout then it might be your thermometer. Test it in ice water and boiling water and see if it hits the right temp consistently.
More insulation (reflectix) may make a huge difference. When I consider the amount of insulation in my cooler mash tun and I still lose 2 degrees, a sleeping bag really isn't that much insulation. A sleeping bag still allows quite a bit of air movement where reflectix not only insulates against the surrounding air but also reflects the radiant heat back at the pot.

If you invest in a roll of reflectix and make a custom wrap for your pot it will likely do a better job and not require you to lift it in and out of the sleeping bag. It will also help your pot come to boil faster and maintain boil better. Especially if you do a double wrap on sides, top and bottom.

 

[specialkayme]

If your pot is aluminum it will lose much more heat than stainless and could account for the increase.

Nope. 304 Stainless Steel. Plus it's 1.5mm thick on the walls, which is thicker than most competitors.

Heat rises so the top of the mash will usually be warmer than the bottom. If you are getting the same temp throughout then it might be your thermometer.

I don't measure it throughout. Just the top 3" or so.

More insulation (reflectix) may make a huge difference.

I appreciate the suggestion, but I was really trying to avoid the "add more insulation" thing. Reflectix is cheap, but it starts taking things down a direction I'd like to avoid.

Most people do fine with a sleeping bag. I don't. So what do I need now? A layer of reflectix (making my nice looking kettle not so nice looking). That works for most people. But then again a sleeping bag works for most people. So what if reflectix doesn't work? A second layer of reflectix. And if that doesn't work? Two layers of reflectix and a sleeping bag. And if that doesn't work? Two layers of reflectix, a sleeping bag, and something to fill the dead space. And if that doesn't work . . . . .

It seems like it might be a whole lot easier to turn my heating element up 5 or 10%. If it won't burn the bag that is.

 

[LittleRiver]

...It seems like it might be a whole lot easier to turn my heating element up 5 or 10%. If it won't burn the bag that is.

Agreed. I am at a loss to explain your heat loss numbers. Let us know how it goes with using the element to help maintain temp.

 

[specialkayme]

The one thing I didn't mention is that my ball valve protrudes out of the sleeping bag when I mash. It's too large to fit in the bag. That may account for some of the heat loss. Although I doubt it's enough to account for a 12 degree loss.

 

[specialkayme]

Well color me confused.

I ran an experiment today to determine what percentage of power I'd need to use with just water. I ran it both with the sleeping bag wrapped around the kettle, and without it.

I also took photos of how I insulate the kettle (sleeping bag on table, cutting board down, kettle, then pull over the kettle).

I first ran the experiment without the sleeping bag:
1. I brought the water up to 161.6 degrees, set the power to 5%. After 20 min the temp dropped to 158.1 (-3.5 degrees).
2. I increased the power to 10%. After 20 min the temp dropped to 149.0 (-4.3 degrees).
3. I increased the power to 15%. After 20 min the temp dropped to 144.8 (-4.8 degrees).
4. I increased the power to 20%. After 20 min the temp dropped to 140.6 (-4.2 degrees).
5. After losing 21 degrees in 80 min (largely because I opened the lid every 20 min to check the temp), I reheated to 153.5. I increased the power to 30%. After 20 min the temp dropped to 152.6 (-0.9 degrees).
7. I reheated to 157.2, increased the power to 35%. After 20 min the temp increased to 157.4 (+0.2 degrees).

So without the bag, the power needed would likely be between 30-35% (34% if I'd have to guess).

I then repeated with the sleeping bag:
1. I brought the water up to 159.6 degrees and set the power to 25%. After 20 min the temp dropped to 157.1 (-2.5 degrees).
2. I increased the power to 30%. After 20 min the temp increased to 158.0 (+0.9 degrees).

So with the bag, the power needed would likely be between 25-30% (28% if I'd have to guess).

So it doesn't seem like the sleeping bag is really doing much to help me out.

To make matters more confusing, I then threw off the sleeping bag, pulled out the power, left the lid on, and walked away for 3 hours. When I came back the temp was 146.3 degrees. So it dropped 11.7 degrees in three hours. With the above temp drops, and previous experieince, I would have expected it to drop SIGNIFICANTLY more than that.

Does any of this information, or the pics, help anyone diagnose my issue?

I'm very hesitant to throw a bag in there with the heat on at 30%. If it was something very low I could probably be ok with taking the risk. But a third seems risky.

 

[LittleRiver]

You're losing a significant amount of heat each time you open the insulation and the lid to check the temp. Have you thought about a remote probe thermometer? I use the ChefAlarm. It has a lot of useful features.

I leave it in for the mash, but I don't really use it to constantly monitor mash temps. That's because I don't have to, I don't have the kind of heat loss issues you are seeing, using only a $14 youth sleeping bag for insulation.

Other than that suggestion I'm still stumped about your heat loss.

 

[Carolina_Matt]

I wonder if the headspace is playing a role? I have a 9.5 gallon kettle, so it gets close to the top when I add grains to 7 gallons of water. In your kettle, there's a lot of headspace at the top. Maybe that's a factor?

Also, have you tried throwing the sleeping bag in the dryer to heat it up before hand?

 

[harry_the_face]

If you are going to turn on the element while mashing then you probably need to recirculate too or the temp in the mash bed will be hot in the middle around the element and much colder out at the sides of the pot where the heat is being lost.

That sleeping bad is not very thick. Might consider getting a wool blanket or a fiberglass welding blanket from Harbor Freight to wrap it in.

 

[sicktght311]

I don't measure it throughout. Just the top 3" or so.

Are you stirring your mash before you take this temperature? That could be your answer if not. If you’re not recirculating your mash, you can end up with hot and cold spots, and if you don’t stir it before taking a temp reading, you could easily find a temperature reading 10° below your mash target temperature, where only a couple inches lower the temperature is at or above mash temperature

 

[Jayjay1976]

Yes of course you can put your sack directly on the element....well, once anyway.

Get yourself a false bottom to keep the bag from contacting the element. Mine sits only 1/4" above the elements but it works fine. I got it from brewhardware.com

 

[Kharnynb]

my guess here is inaccurate temp readings, this makes no sense otherwise.

I would heat your strike water another 10 degrees, and mix at least a minute more than you've done so far.

 

[specialkayme]

Have you thought about a remote probe thermometer?

I have a port on the kettle ready for a thermometer. I just haven't gotten around to ordering it yet.

I agree that I'm losing temp by opening it up. But it still doesn't explain the heat loss over 60 min when I don't remove the lid or open it up.

 

[specialkayme]

I wonder if the headspace is playing a role?

Probably does. I just wouldn't have imageined that factor alone would account for that level of continuous loss.

Also, have you tried throwing the sleeping bag in the dryer to heat it up before hand?

I hadn't thought of that. Not bad of an idea.

 

[specialkayme]

Get yourself a false bottom to keep the bag from contacting the element.

My kettle is 15.75" in diameter, and I'd need a 3.5" lift off the bottom to clear the element. Best fit brewhardware.com has is a 14.75" with a 4.25" lift. But it has a foot in the direct center, which won't work as it'll contact the element.

But assuming I found a different one that would work, wouldn't turning the heating element up to 35% power create more of an intense heat that's concentrated on the bottom, scorching the grain?

 

[specialkayme]

my guess here is inaccurate temp readings, this makes no sense otherwise.

The javelin thermometer is pretty accurate. It calibrates exactly to frozen and boiling water, and has been accurate on all of the meats that I grill out. So I don't think it's the thermometer.

My readings are always taken 3" below the surface of the water in the dead center of the kettle. Both the first and the last readings are taken in the same spot. So if it was an inaccurate temp reading process, wouldn't it show off readings on both checks, and not just one? Or if the spot that I checked wasn't a true representation of the actual temp in the kettle, would it make sense that the spot that I checked was 7-10 degrees of deviation from the temp a foot further down? That doesn't make sense to me either.

 

[Kharnynb]

if you don't mix well, the water on top will be hot water, but the grain and water will not have equalised their temperature.

of course, after an hour the temp will have evened out all over the kettle by simple time mixed.

 

[BeardedBrews]

Before I went to a basket I used a bag with the element on. It works, but not well. Some tips:

1. I experienced a big gradient between the temperature in the middle of the grain bed and the edges/top. If I measured the top right after I opened the lid it would show a loss of 10f, then I'd stir with my big whisk and the temp would even out to a loss of only 3-4f.

2. If I wasn't actively stirring the mash when I turned on the heat it would boil and thump against the element (even at 15%). The grain is a good insulator so all the heat gets trapped right there.

3. Stirring and heating every 15 minutes was a bit of a pain in the ass.



Switching to a false bottom would be easier, but it won't get around the issue of stirring. Your insulation set up looks pretty good, I might not spend much money improving that since at some point you're likely to upgrade from the still dragon to an actual temp controller.

 

[BeardedBrews]

My kettle is 15.75" in diameter, and I'd need a 3.5" lift off the bottom to clear the element. Best fit brewhardware.com has is a 14.75" with a 4.25" lift. But it has a foot in the direct center, which won't work as it'll contact the element.

But assuming I found a different one that would work, wouldn't turning the heating element up to 35% power create more of an intense heat that's concentrated on the bottom, scorching the grain?

Having the legs touching the element won't hurt it, but the Brew Hardware legs are also removable. You can slightly bend the element out of the way too.

 

[Bobby_M]

Are you measuring losses in an actual mash or was it only based on a water test? Huge difference. What temp do you target for strike water?

 

[hezagenius]

The brewhardware 14.75 in a 15.75 works well. That's my configuration. Take up any slack in your bag on the outside of the kettle and you are good. And you can slide the false bottom to cover all of the element if you are worried. The foot in the middle is not necessary. It will hold the weight with the 4 outside legs.

If you want to set it and forget it scenario, you should try recirculating during the mash

 

[specialkayme]

1. I experienced a big gradient between the temperature in the middle of the grain bed and the edges/top. If I measured the top right after I opened the lid it would show a loss of 10f, then I'd stir with my big whisk and the temp would even out to a loss of only 3-4f.

Interesting. I'll have to check that out.

Your insulation set up looks pretty good, I might not spend much money improving that since at some point you're likely to upgrade from the still dragon to an actual temp controller.

Yeah, I was hoping to avoid that. But if I want to get the results I'm expecting, I realize I'll need a false bottom, a more advanced temp control system, and a recirculating pump. In due time I guess though.