Question on heat for BIAB mash

I am considering do a BIAB 10g batch next since the weather is quite cold right now and was curious if it is possible (easy) to say keep the burner on a low setting to keep the mash temp.

I suppose it could be possible but many different factors would play into keeping the temp stable and where you want it. Air temp, wind, humidity, burner etc. Wouldn't it be better to rig up/use significant and effective insulation? The thermal mass of the volume of water and weight of grains that you'd have going, to end up with a 10 gallon batch, should hold temp really well if properly insulated. Then again, that might also make it easier to maintain temp with a burner on low, too

Only done stovetop BIAB, 2.5 gallon batch myself and found adding heat as needed, stirring and being very attentive, helped me keep a reasonably constant temp over the hour.

I have a few biabs under my belt and researched it quite a bit. Some people say you can and not worry about burning your bag. But i took a lighter to a corner of the fabric and it lights off pretty good. I wrap my pot with reflectix wrap and i barely lose a degree in a 60 minute mash. There is a pretty good thread here somewhere that i got it from

Wrap it with a blanket. You can check the temp and give it a stir every 15 minutes or so, but I have some experience with direct fired mashing, and it's REALLY easy to overshoot your temp.
Overshooting the temp is way worse than mashing low IMHO.

Done a couple BIABs at 52 or so ambient temps and had strike water hit 161 for mashing at 154. Hit it on the dot a couple times now and mashed for 60 minutes, checking every 15 with consistent temps.

Only seem to lose 3-4 degrees after 45 minutes, so I light and raise it up a bit. I cover my clad bottom megapot with a blanket. I'd be scared of mashing way too hot if I left the burner on.

I say give it a shot and re-apply heat if you need to.

I wrap it in an old sleeping bag then bungee cord it. Temp stays stable for 90 minutes.

LabRatBrewer said:

I wrap it in an old sleeping bag then bungee cord it. Temp stays stable for 90 minutes.

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I agree. I do 2.5 gallon biab and wrap my pot in an old comforter and holds temp for 90 minutes

I pull mine off the burner and place it in the center of an old comforter that I have laid out on the ground. I then wrap it up with the comforter and some towels/ one of my torn Brazilian Jiu-Jitsu gi's. It holds pretty well, but I do lose a couple degrees over the full hour. I've been meaning to get around to the old reflectix trick, but I haven't actually looked that thread up.

Put a small spaghetti strainer at the bottom of the kettle. The bag could rest on it without getting scorched.

When doing BIAB and adding heat it is really hard to keep from overheating the bottom as the heat doesn't circulate in that mash. You would have to stir constantly to keep it from stratifying and that stirring loses heat then too. It's better to just insulate the mash tun (kettle) better. If your crush is really fine as it should be for BIAB, conversion will happen in 15 to 20 minutes so if your mash cools too far in an hour you might be able to shorten the mash time.

^ Good point.

I've actually been thinking of getting a pump to get a recirculation going during the mash, with an inline thermometer to easily monitor mash temps

I'm planning on doing this tomorrow.

Here's the reflectix wrap post---> https://www.homebrewtalk.com/f11/keggle-insulation-keg-koozie-vs-reflectix-pics-301888/

Just make sure you watch the burner or take off the wrap if you're increasing the heat during the mash.

The bottom of mine melted a bit, even on low heat.

Sort of on the same subject, could the mash process be done in a 10 gallon cooler the same way it is done in a pot and then transferred to the kettle? I'd like to go BIAB route but its pretty cold here. I have a 10 gal cooler, just never converted one. Thank you.

Sure it could but that is one more vessel to clean. Can you get the same or nearly the same insulation from a sleeping bag?

Remember that you are doing BIAB and that

If your crush is really fine as it should be for BIAB, conversion will happen in 15 to 20 minutes so

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So you lose a couple degrees, no big deal if the mash is nearly over.

Ive been thinking about getting a cooler for winter BIAB. For me personally, i would rather give a cooler a quick rinse. Its not like its getting stuck on deposits or has to be sanitized.

If I mash outside during winter I will lose close to 5 degrees in around 30 min, and that's with the insulation. We get a pretty mean wind chill coming across the lake here in Cleveland!