BIAB Disadvantages to go with the Advantages thread.

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Nubiwan

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That's actually why I've been doing multi-step mashes with my BIAB. 2-3 steps usually. More mixing, more control over the fermentability and mouthfeel of the product, overall better results in my opinion when using unmalted adjuncts.
What are your steps? Feel it is something I could easily engage, rather than just wait for water to reach strike temps. Is it the same process for all recipes?

Can you explain why you think you get better mouthfeel by stepping? What's the rationale?
 

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I either missed or already forgot the point: what's the connection between step mashes and disadvantages of brewing in a bag? I did my usual steps when I used a bag, and now that I replaced it with a home-made stainless steel mesh filter basket, I'm doing the same thing.

Actually, with the bag I was still lautering into a different vessel, so it wasn't true single vessel brew in a bag, whereas today in my first brew with the stainless basket I just lifted the basket, suspended it above the kettle, sparged, and then boiled the wort in the mash tun that was now my brewing kettle. Very convenient, a lot less messy than handling the bag, and exactly the same ~70% overall efficiency as before (5 gallons of 1.050 wort from 10 lbs of grain into the fermenter).
 
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Nubiwan

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Optimal temperature for glycoprotein formation is around 70–72°C.
Not really an answer to why step mashing improves beer over letting it sit around 67 degrees for an hour.

I am used to just single infusion mashes with now minimal concern over a few degrees swing in mash temps. My last effort swung from 154 - 146 degrees (F). Not planned, but it did.

I had had to google your 72 degrees glycopotein response. The Celsius over Fahrenheit threw me off. Assume you are referring to the Hoch-Kurz mash process, which (as far as I could tell) proscribes mashing at intervals of approx 62, 72 and 76 degrees, and involves an awful lot of big words :). I assume the ultimate goal being to get as much fermentables in the wort, among other things, which I confess to rather glancing over. Are the first two temps not also the sweet spots for both beta and alpha amylase activity? An answer I would have understood.

The link I read, made a differentation between decoction and infusion, and I am not sure I entirely get all that other than suspect the act of heating grain somehow degrades it. Are they suggesting pulling the grain while you heat the wort at each step? Not sure.

Another question I'd ask would be, am I not getting the benefit of this process, or close to it, if I start my mash at say 72 degrees, and let it simply fall, over a 90-120 minute period back to 64 degrees give or take a degree or two? Has anyone tried to see if it creates a different resulting beer?

Obviously, a fair bit I am missing. Very interesting to hear it in laymans terms. For example, 72 is optimal for alpha amylase which breaks down longer sugar strands - less fermentable wort. 62 is optimal for Beta, which will breaks down shorter, more fermentables sugars. Think I have that in the right order.

Finally, what if I wanted a low ABV, but malt forward beer? I might want to skip the 62 degree step all together. would I not? Vice versa for a dryer beer.

Still, all fascinating stuff, I have to admit.
 
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RPh_Guy

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Not really an answer to why step mashing improves beer over letting it sit around 67 degrees for an hour.

I am used to just single infusion mashes with now minimal concern over a few degrees swing in mash temps. My last effort swung from 154 - 146 degrees (F). Not planned, but it did.

I had had to google your 72 degrees glycopotein response. The Celsius over Fahrenheit threw me off. Assume you are referring to the Hoch-Kurz mash process, which (as far as I could tell) proscribes mashing at intervals of approx 62, 72 and 76 degrees, and involves an awful lot of big words :). I assume the ultimate goal being to get as much fermentables in the wort, among other things, which I confess to rather glancing over. Are the first two temps not also the sweet spots for both beta and alpha amylase activity? An answer I would have understood.

The link I read, made a differentation between decoction and infusion, and I am not sure I entirely get all that other than suspect the act of heating grain somehow degrades it. Are they suggesting pulling the grain while you heat the wort at each step? Not sure.

Another question I'd ask would be, am I not getting the benefit of this process, or close to it, if I start my mash at say 72 degrees, and let it simply fall, over a 90-120 minute period back to 64 degrees give or take a degree or two? Has anyone tried to see if it creates a different resulting beer?

Obviously, a fair bit I am missing. Very interesting to hear it in laymans terms. For example, 72 is optimal for alpha amylase which breaks down longer sugar strands - less fermentable wort. 62 is optimal for Beta, which will breaks down shorter, more fermentables sugars. Think I have that in the right order.

Finally, what if I wanted a low ABV, but malt forward beer? I might want to skip the 62 degree step all together. would I not? Vice versa for a dryer beer.

Still, all fascinating stuff, I have to admit.
Indeed if you want to know the "why" behind brewing, there a lot to learn. Pretty much everything you wrote is correct.

Decoction mash is not useful with modern malts; it's a historical process for poorly modified malt.

Starting the mash at 70-72°C will quickly denature beta-amylase and produce a rather unfermentable wort. The resulting beer with more dextrins will actually taste less malty. Malt flavor does not come from dextrins; they only serve to mask it.

To further confuse you, much of this depends on the milling of the grain. With the very fine milling I use, the conversion is over and the enzymes mostly denatured well before you could change the mash temperature.
Fine milling would not denature the enzymes any faster, and probably the opposite is true since protein is thermoprotective of beta amylase.
 

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Not really an answer to why step mashing improves beer over letting it sit around 67 degrees for an hour.

I am used to just single infusion mashes with now minimal concern over a few degrees swing in mash temps. My last effort swung from 154 - 146 degrees (F). Not planned, but it did.

I had had to google your 72 degrees glycopotein response. The Celsius over Fahrenheit threw me off. Assume you are referring to the Hoch-Kurz mash process, which (as far as I could tell) proscribes mashing at intervals of approx 62, 72 and 76 degrees, and involves an awful lot of big words :). I assume the ultimate goal being to get as much fermentables in the wort, among other things, which I confess to rather glancing over. Are the first two temps not also the sweet spots for both beta and alpha amylase activity? An answer I would have understood.

The link I read, made a differentation between decoction and infusion, and I am not sure I entirely get all that other than suspect the act of heating grain somehow degrades it. Are they suggesting pulling the grain while you heat the wort at each step? Not sure.

Another question I'd ask would be, am I not getting the benefit of this process, or close to it, if I start my mash at say 72 degrees, and let it simply fall, over a 90-120 minute period back to 64 degrees give or take a degree or two? Has anyone tried to see if it creates a different resulting beer?

Obviously, a fair bit I am missing. Very interesting to hear it in laymans terms. For example, 72 is optimal for alpha amylase which breaks down longer sugar strands - less fermentable wort. 62 is optimal for Beta, which will breaks down shorter, more fermentables sugars. Think I have that in the right order.

Finally, what if I wanted a low ABV, but malt forward beer? I might want to skip the 62 degree step all together. would I not? Vice versa for a dryer beer.

Still, all fascinating stuff, I have to admit.
The problem with this approach is that beta-amylase denatures rather quickly at 72°C (162°F), so that when you reduce the temp back to 64°C (147°F), there will be little to no beta-amylase left.

Brew on :mug:
 

Nubiwan

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To further confuse you, much of this depends on the milling of the grain. With the very fine milling I use, the conversion is over and the enzymes mostly denatured well before you could change the mash temperature.
I've read that before too @RM-MN. You are the king of the short mash :) . So why the fuss stepping, was my next question. Since many (like you) purport the mash is over quickly, in certain cirumstances.

Finely crushed grain not optimal for the LODO experience unless you under insert the grain somehow, I understand. Something I cannot do with BIAB.

I will say this, my 2.5 hour mash (154-146 degree mash swing) for my recent amber dropped from OG 1.058 to 1.006, so no one can tell me I missed either end of the amylase breakdowns. Or can they?

Wonder sometimes if we just wanna make things difficult.

Think I'll incorporate some LODO advice into my HSA component next batch. See if I can up the flavour any. Cant hurt to pre-boil my water and cool it. Gonna give it a try. My bottles will put paid to that effort no doubt. Gotta get me a keg or two.
 
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Nubiwan

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The problem with this approach is that beta-amylase denatures rather quickly at 72°C (162°F), so that when you reduce the temp back to 64°C (147°F), there will be little to no beta-amylase left.

Brew on :mug:
I've read this to be true before too but have anecdotal evidence to the contrary, which is why I posed the question.

Please explain why the brew I just bottled (shame on bottles I hear), was mashed for 2.5 hours (not out of choice or design-just happened as I had to drop off my kids), dropped from 154 degrees to around 146. My fermentation gravity went from 1.058 to 1.006. A bigger (6.8% ABV) beer for me, as I usually aim around 5%. Same recipe at 1 hour mash yielded maybe 5.5% ABV about a month ago. I could argue my beta amylase was alive and well - or something else, broke down the larger sugars to acheive this.

Perhaps because my mash started at 154, not 162 degrees. Likely, yes? I don't do a 10 minute 170 burn, just go straight to boil.

This is why I love brewing at times. Soo much to learn and / or demystify.
 

doug293cz

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I've read this to be true before too but have anecdotal evidence to the contrary, which is why I posed the question.

Please explain why the brew I just bottled (shame on bottles I hear), was mashed for 2.5 hours (not out of choice or design-just happened as I had to drop off my kids), dropped from 154 degrees to around 146. My fermentation gravity went from 1.058 to 1.006. A bigger (6.8% ABV) beer for me, as I usually aim around 5%. Same recipe at 1 hour mash yielded maybe 5.5% ABV about a month ago. I could argue my beta amylase was alive and well - or something else, broke down the larger sugars to acheive this.

Perhaps because my mash started at 154, not 162 degrees. Likely, yes? I don't do a 10 minute 170 burn, just go straight to boil.

This is why I love brewing at times. Soo much to learn and / or demystify.
There is a lot of misunderstanding about how alpha-amylase actually works. Alpha-amylase doesn't create chains, it cuts them. Alpha cuts glucose chains (starch and dextrin) at random locations, leaving two shorter chains from one longer chain. If you keep on cutting the chains, the remaining pieces get shorter and shorter. This eventually leads to fermentable sugars. The longer you mash, the more fermentable sugar alpha can create (this is why a mash out is done when fly sparging - to keep the wort from getting too fermentable during the sparge.) Alpha (and beta) cannot work within a certain distance of a chain branch point. Once all the chains are reduced to branch points with short chains emanating from the branch point, all amylase action stops. These remaining small, branched pieces are limit dextrins, which are unfermentable.

Brew on :mug:
 

Nubiwan

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There is a lot of misunderstanding about how alpha-amylase actually works. Alpha-amylase doesn't create chains, it cuts them. Alpha cuts glucose chains (starch and dextrin) at random locations, leaving two shorter chains from one longer chain. If you keep on cutting the chains, the remaining pieces get shorter and shorter. This eventually leads to fermentable sugars. The longer you mash, the more fermentable sugar alpha can create (this is why a mash out is done when fly sparging - to keep the wort from getting too fermentable during the sparge.) Alpha (and beta) cannot work within a certain distance of a chain branch point. Once all the chains are reduced to branch points with short chains emanating from the branch point, all amylase action stops. These remaining small, branched pieces are limit dextrins, which are unfermentable.

Brew on :mug:
So, what difference is this to step the mash process? Are these any different sugars from the longer mash process! Is there any evidence to suggest my beer would be different had I done the step process? Apologies to OP, as itsnow rather off topic?
 

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So, what difference is this to step the mash process? Are these any different sugars from the longer mash process! Is there any evidence to suggest my beer would be different had I done the step process? Apologies to OP, as itsnow rather off topic?
Lower temperatures give good fermentability. Higher temps give the best mouthfeel, foam, and extraction. Therefore a step mash gives the best of both worlds, while a single infusion provides a compromise.

The longer you mash, the more fermentable sugar alpha can create (this is why a mash out is done when fly sparging - to keep the wort from getting too fermentable during the sparge
The purpose of a mash-out is not to denature the enzymes, but rather provide easier lautering and sparging, and maximize extract.

Paraphrasing Kunze:
Undissolved starch may be washed out of the grain during sparging, which may cause haze if it isn't converted. Therefore it's important for alpha-amylase to remain active during lautering, and so the temperature must not exceed 76-78°C.
 
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Gruel

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Reverse step mashing:
It might be interesting to set some portion of the mash (1/3?) aside with beta-amylase still fully intact (not heated above 65C), bring the rest of the mash to 72C for alpha-amylase activity, let the alpha-amylase do its job on this part of the mash, and then cool it down again to 62C and mix it with the beta-amylase portion that was set aside. It's not exactly a decoction, since nothing gets cooked.

Is this being done, or has it been tried? Would it make too dry a beer?

And to come back to the original thread topic, this would be difficult to do in a bag...
 

RPh_Guy

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Reverse step mashing:
It might be interesting to set some portion of the mash (1/3?) aside with beta-amylase still fully intact (not heated above 65C), bring the rest of the mash to 72C for alpha-amylase activity, let the alpha-amylase do its job on this part of the mash, and then cool it down again to 62C and mix it with the beta-amylase portion that was set aside. It's not exactly a decoction, since nothing gets cooked.

Is this being done, or has it been tried? Would it make too dry a beer?

And to come back to the original thread topic, this would be difficult to do in a bag...
 

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Thanks, RPh_Guy, very interesting. So, this is indeed described as a more logical sequence by Weihenstephan brewing faculty. Additionally they mention that by doing a real decoction and going close to boiling after doing the 72C alpha-amylase rest with 1/3 of the mash brings added benefits for antioxidants, foam and flavor stability.
What's not clear to me from the article is whether they merely describe what is going on in standard decoction, or whether they suggest this as a modified procedure. The article is called 'reflections on mashing', so it could be either. The introduction to the article encourages exploiting the flexibility in mash schedules and the adoption of new methods, so that makes me think they are suggesting this.

I think I have to try this.

We should try to get back to the topic of the thread though.
 

RPh_Guy

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Thanks, RPh_Guy, very interesting. So, this is indeed described as a more logical sequence by Weihenstephan brewing faculty. Additionally they mention that by doing a real decoction and going close to boiling after doing the 72C alpha-amylase rest with 1/3 of the mash brings added benefits for antioxidants, foam and flavor stability.
What's not clear to me from the article is whether they merely describe what is going on in standard decoction, or whether they suggest this as a modified procedure. The article is called 'reflections on mashing', so it could be either. The introduction to the article encourages exploiting the flexibility in mash schedules and the adoption of new methods, so that makes me think they are suggesting this.

I think I have to try this.

We should try to get back to the topic of the thread though.
Be sure to also read part 2 :)
 
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Gruel

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Aha, the plot thickens! It sounds like they are wistful about the demise of decoctions, and advertise all the fancy things you can do with them. Also, in part one they talked about boiling (or almost boiling) the alpha-amylase mash part, but in part two they admit that decoction fell out of favor because of time and energy use, and suggest just going to 72C. It seems I'm just four years late with my suggestion, but I'm glad to hear it's not completely crazy. Although, Narziss is an emeritus, what does he have to loose? :mug: Just joking.

They must have an army of grad students there, coming up with a gazillion ways to brew differently. Sometimes not completely legal, like when they were in the news for suggesting seaweed for better head retention.

Then they also talk about how to compensate for bad grain harvests; I'm not sure I would ever find out if a year was a bad year for barley...

Thanks again for posting this, RPh_guy. You're sure you're not a chemist?
 

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I'm trying to imagine the first brewers in history concerned with LODO practices, decoctions, step mash temps, lautering and pH and thinking, I'm already in far better control of the process, with my lowly single infusion BIAB process, than they could ever have been, even whilst erecting those tricky pyramids?

Do all the complications, vessels, theories and time we throw at the craft really warrant a better beer result? Always? I say they do not.

It occurs to me that in many independent tastings, people still prefer the simply brewed beer over something supposedly more finely tuned. Many times, even "experts" (I'm sure they know who they are) can't tell two beers apart, in tests where the expected difference was significant, based on some tradition or scientific premise.

I'm happy with my beer, and so are several neighbours. Willing to try anything to make it better. But I am fully aware of the above truths.
 

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Then they also talk about how to compensate for bad grain harvests; I'm not sure I would ever find out if a year was a bad year for barley...
Bad year for barley where? Barley is grown over a big enough area in the US that one can be fairly sure that there are good and bad grain harvests every year. Things like a thunderstorm that is only 20 miles across that hits one set of fields and not another are one such factor. That can make a difference in fields only a mile apart.
 

Gruel

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Bad year for barley where? Barley is grown over a big enough area in the US that one can be fairly sure that there are good and bad grain harvests every year. Things like a thunderstorm that is only 20 miles across that hits one set of fields and not another are one such factor. That can make a difference in fields only a mile apart.
That's just me paraphrasing it. It makes more sense if you read the article.
 

Gruel

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I'm trying to imagine the first brewers in history concerned with LODO practices, decoctions, step mash temps, lautering and pH and thinking, I'm already in far better control of the process, with my lowly single infusion BIAB process, than they could ever have been, even whilst erecting those tricky pyramids?

Do all the complications, vessels, theories and time we throw at the craft really warrant a better beer result? Always? I say they do not.

It occurs to me that in many independent tastings, people still prefer the simply brewed beer over something supposedly more finely tuned. Many times, even "experts" (I'm sure they know who they are) can't tell two beers apart, in tests where the expected difference was significant, based on some tradition or scientific premise.

I'm happy with my beer, and so are several neighbours. Willing to try anything to make it better. But I am fully aware of the above truths.
The article actually talks about a simple single decoction, and the freedom it gives you in picking an almost arbitrary temperature sequence. Again, me paraphrasing and simplifying.

I find the two articles (or two parts of one article) very entertaining and worthwhile. There is nothing complicated in the decoction schedule. It's fewer steps than I'm currently doing.
 

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The article actually talks about a simple single decoction, and the freedom it gives you in picking an almost arbitrary temperature sequence. Again, me paraphrasing and simplifying.

I find the two articles (or two parts of one article) very entertaining and worthwhile. There is nothing complicated in the decoction schedule. It's fewer steps than I'm currently doing.
Merely a general comment about the hobby/craft, and not directed at anything or anyone in particular. I wasn't referencing the article. Don't think i read the last one mentioned.
 

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To further confuse you, much of this depends on the milling of the grain. With the very fine milling I use, the conversion is over and the enzymes mostly denatured well before you could change the mash temperature.
I would guess probably not if your first step is 132F.

Sorry that I missed the discussion, some big life changes! Basically, I don't like to mill super fine. Nothing against it, just preference. I just find that using 2-3 steps lets me control a lot more variables than a single infusion temp. Once again, nothing wrong with that.

My usual is either: Low mash (145-148), Mid mash (154ish), Mashout (168) or Protein rest, mash, mashout. If I feel like being a jerk: Acid rest, protein rest, low mash, mid mash, mashout :ghostly: I have made some very good beers this way, especially lively little3-4% saisons with a good amount of unmalted adjunct.

The shorter schedules are inspired by English brewing and their "underlets." With my small volume brewing (3 gallons in the keg), all of these additions are done by boiling brewing water in a countertop electric kettle, adding, and stirring.
 

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I would guess probably not if your first step is 132F.

Sorry that I missed the discussion, some big life changes! Basically, I don't like to mill super fine. Nothing against it, just preference. I just find that using 2-3 steps lets me control a lot more variables than a single infusion temp. Once again, nothing wrong with that.

My usual is either: Low mash (145-148), Mid mash (154ish), Mashout (168) or Protein rest, mash, mashout. If I feel like being a jerk: Acid rest, protein rest, low mash, mid mash, mashout :ghostly: I have made some very good beers this way, especially lively little3-4% saisons with a good amount of unmalted adjunct.

The shorter schedules are inspired by English brewing and their "underlets." With my small volume brewing (3 gallons in the keg), all of these additions are done by boiling brewing water in a countertop electric kettle, adding, and stirring.
Same for any recipe? Do you tune it for different beer types?
 

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Same for any recipe? Do you tune it for different beer types?
Definitely tweak it for the recipe. I tend to prefer my beers dry so I most often find myself doing a long rest 145-148ish, bump to mid 150's, then mashout batch sparge. But you can easily start higher, or do only 15-20 minutes at the lower temp, etc. etc...
 

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Definitely tweak it for the recipe. I tend to prefer my beers dry so I most often find myself doing a long rest 145-148ish, bump to mid 150's, then mashout batch sparge. But you can easily start higher, or do only 15-20 minutes at the lower temp, etc. etc...
Not sure it's been asked. You leave your bag in when you heat your kettle?
 

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I don't heat my kettle. Boiling water additions. Green Bay Rackers--Mash Calculators
So risk of leaving bag in is scorching, I assume. Or is there something else to consider? Does grain or bag really get scorched at 145-160 degrees?

Pretty sure my bag is off the bottom of my kettle, if I wanted to try this.

Guess I am getting at stepping at full volume, and just heating the kettle. Anyone doing or tried this?
 

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So risk of leaving bag in is scorching, I assume. Or is there something else to consider? Does grain or bag really get scorched at 145-160 degrees?

Pretty sure my bag is off the bottom of my kettle, if I wanted to try this.

Guess I am getting at stepping at full volume, and just heating the kettle. Anyone doing or tried this?
The grain bag sitting on the bottom of the BK (in a propane fired system) or on the heating element (electric fired system) severely limits heat transfer away from the heat source. This causes local temps to be much higher than average temps, and this can lead to scorching.

Brew on :mug:
 

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So the one time I have done this, I had my sparging/lautering copper manifold at the bottom of the kettle. The bag might still have touched the bottom of the kettle between the coils of the manifold. The only partial melting/hardening of the bag that occurred on my gas powered range was around the edges of the kettle where I had draped the bag over it (which is pretty messy to begin with, and not recommended). I ran a 15,000 BTU burner at the medium setting, with an aluminum foil heat spreader below the kettle (the aluminum foil - folded - will disintegrate; I now switched to a more solid aluminum sheet; of course a kettle with a sandwich bottom would be best). So, I think you can heat the mash kettle with the bag inside.

Note that at full power I can produce scorch marks of burnt starch (I assume) on the inside of the thin walled steel kettle.
 
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