Winter BIAB

[Piperlester]

Hello from the Great White North!

So, it seems Old Man Winter is coming early and it's starting to become a challenge to hold mash temps in the unheated garage. I'm seeing 2-3F drop every 15 minutes during the mash, which is going to lead to some very dry beer if I don't keep heating. The catch is it is a huge pain in the arse to pull off the insulation, strike the burner and stir while measuring to make sure I don't overshoot too badly.

My question is this... for those of you BIABing in cold weather, how do you handle this? My initial thought is overshoot by 4-6F at the start and let it drift downwards. My only worry is denaturing the enzymes too quickly and ending up with low fermentability.

 

[mongoose33]

One option is more insulation. One area that we usually don't concern ourselves with is the bottom of the kettle; hard to move it to insulate it, but perhaps after your burner is off, there's a way to use something like foamboard to plug up the area under the kettle.

Another idea is to use something to provide supplemental heat. A 100-watt incandescent bulb under the burner can also provide enough heat to eliminate that part of the system from losing heat.

Have a fermwrap or something similar? You could wrap that around at least part of the insulation you have over the kettle, which will also limit the area losing heat.

Do you have a spotlight/floodlight? They're often something that throw off a lot of heat. Set it up so it is close to the insulation and shine it on the insulated mash tun. It'll help.

When I was doing a cooler mash tun in my garage in the winter months, I'd put the cooler on top of a reptile heat mat, which didn't do a lot to heat the cooler, but it limited heat loss to the material it was sitting on.

So: more insulation, incandescent light bulb underneath, maybe a fermwrap round the outside, shine a spotlight on it.

 

[GoeHaarden]

I'm giving BIAB a try soon, so no real experience to provide.

I have thought about this problem as I too brew in an unheated garage, and I think I'm going to heat strike water with garage door open. Dough-in, close garage door and possibly aim a dish heater at the kettle if I get dramatic temp drops. Haven't tried this so I dont know if it works but it seems like it should help.

I've also heard that with BIAB a good fine crush most conversion is complete by 30 minutes, sometimes shorter but flavor extraction suffers when less than 30min. So crushing finer to decrease mash time is a sort of work around...

 

[mongoose33]

I'm giving BIAB a try soon, so no real experience to provide.

I have thought about this problem as I too brew in an unheated garage, and I think I'm going to heat strike water with garage door open. Dough-in, close garage door and possibly aim a dish heater at the kettle if I get dramatic temp drops. Haven't tried this so I dont know if it works but it seems like it should help.

I've also heard that with BIAB a good fine crush most conversion is complete by 30 minutes, sometimes shorter but flavor extraction suffers when less than 30min. So crushing finer to decrease mash time is a sort of work around...

I've thought that if you can keep your temps close to what you want for the first 30 minutes, you'll be ok--and flavor extraction isn't enzymatic, so even if the temp drops, it's probably not going to be an issue there.

 

[GoeHaarden]

I've thought that if you can keep your temps close to what you want for the first 30 minutes, you'll be ok--and flavor extraction isn't enzymatic, so even if the temp drops, it's probably not going to be an issue there.

Yeah, that's my understanding as well. I think that going less than 30 minutes is where the flavor extraction is decreased.

I've always been curious about the results of a rapidly decreasing mash temp after the amylases have done their job? I assumed it's conversion stopped once temp drop out of its range, but I've never delt with that dramatic of a drop.

 

[MaxStout]

I've done some brewing over propane in a cold garage, though if it gets below about 20-25F it's no longer enjoyable for me (I do 2.5 gal BIAB on the stove in the dead of winter, but that's another story). Anyway, I just shoot for my mash temp as usual, dough in then cover with an old blanket. Take a temp reading after 10-15 minutes, and if it has dropped lower than target minus 2, I fire up the propane at very low heat for a minute or so while constantly stirring and bring it to target plus 1 or so. After about 30 minutes I figure most of the conversion is done, and I let it ride out to 60 minutes.

 

[NewJersey]

Go electric!

 

[RM-MN]

Go electric!

Using an electric range in the kitchen is a viable alternative to a cold garage but many of them won't bring 6 1/2 gallons to a boil. Add a heat stick and you're there. Not very expensive for a heat stick. Biggest problem is removing the bag of grains.

 

[myndflyte]

If you can't add more insulation to your pot, have you thought about mashing in a 10 gallon cooler if you have one or can get one cheap? I use my ex-traditional cooler mash tun as my BIAB mash tun now, mainly because my pot is only 9 gallons, but also because it holds temps like a champ.

 

[wepeeler]

I did something very similar to this: https://www.clawhammersupply.com/bl...og/how-to-insulate-a-biab-brewing-boil-kettle I wrapped my kettle 2x with the insulation. And then wrap that in a sleeping bag. I drop maybe 4-5 degrees during a 60 min mash in the dead of winter.

 

[balrog]

I brew all winter in garage, in New England.
Milk crate on floor to get off concrete
Moving blanket spread out, middle blanket over crate
Two folded towels on crate
kettle off burner at strike temp onto towels, lid on, wrapped with two layers reflectrix, blanket lifted up with corners laid on kettle top
I used to then put a sleeping bag wrapped around the whole thing, but found I only lost about 4° over the hour and I only really care during the 5-10m of conversion at the beginning anyway.

Now I just set on towels on crate (ref @mongoose33 point about the kettle bottom) and wrap the reflectrix and I'm good. Even when it's been -8° outside. Mash was happy.

My toes and fingers were not as ecstatic.

 

[Parkinson1963]

At -25c I use my normal insulation plus two sleeping bags and two old work coats to insulate. I lose about 3 to 5c over the hour.

 

[RM-MN]

At -25c I use my normal insulation plus two sleeping bags and two old work coats to insulate. I lose about 3 to 5c over the hour.

You're doing quite well to only lose 3 to 5C over an hour but how much have you lost when conversion is complete? During conversion is the only time the temperature really matters and if you take a full hour for conversion your wort will be quite fermentable with a 5C temperature drop. If you have your grains milled really fine, conversion happens very quickly and you may not have lost more than 1C.

 

[North_of_60]

When I lived in Alaska I mashed in the house and boiled outside.

 

[LittleRiver]

... unheated garage... 2-3F drop every 15 minutes... huge pain in the arse to pull off the insulation, strike the burner and stir while measuring... how do you handle this?...

As others have already posted, if your grain is crushed very finely you are only worried about the first 10-15 minutes regarding conversion. Since you are within 2-3F of target for that time, you should be good to go with your current process.

Are you removing insulation to check temp? If so, you're losing a lot of heat each time. A remote probe thermometer will allow you to monitor temps without disturbing the insulation. I use a Thermoworks ChefAlarm with a modified (waterproofed) probe, because I like its alarm & timer functions.

I use an old sleeping bag for insulation. I carefully tuck it around the bottom of the burner and tie a cord around it so everything stays put. In warmer months I stay within one degree, in colder months I lose a few more degrees, but not within the first 10-15 min.

 

[balrog]

Yea the thermal mass of 7gal of water and 10# of grain will hold a pretty steady temp for 10-15m without much effort.

 

[OG-wan Kenobi]

I use 5 blankets and 2 bungie cords to secure them to the kettle in the winter you can also consider an electric blanket as being part of the mix if needed but my mash temps go up 2 (3 in the summer with 3) degrees and hold solid from there I brew in New England in my garage just know you got to fold those blankets when your done or the wife will be unpleasant about it trust me don't just throw them on the kids bikes and tell her you forgot it's quicker to fold them

 

[NitrogenWidget]

I brewed once in the winter last yr and that was enough for me. I’m currently brewing every weekend to make sure I got enough beer to last me until I get a stove setup in the basement. Yesterday it was 40 out and no wind so kind of warm. I used a wool blanket, sleeping bag, and moving blanket and I dropped only a few degrees over the hour with a 10 gallons batch. 5 gallon batches cool quicker I’ve noticed.

 

[rabbitburger]

My question is this... for those of you BIABing in cold weather, how do you handle this? My initial thought is overshoot by 4-6F at the start and let it drift downwards. My only worry is denaturing the enzymes too quickly and ending up with low fermentability.

I am in Canada too, and most recently BIAB'd on Sunday, outside, around -3 ambient. I use a sous vide during mash, and had no trouble at all.

 

[mirthfuldragon]

I'm seeing 2-3F drop every 15 minutes during the mash, which is going to lead to some very dry beer if I don't keep heating.

In my experience, mash temperature matters less than you think it does. I do 90-minutes mashes with an initial target strike temperature for 149-150°, oxygenate, and pitch active starters, and my FGs are typically at or near the bottom end of the style guide. I like my beers on the drier side, so here I am intentionally aiming for dry beers, and not quite getting there. My last hefe finished at 1.010 on the nose, and I wanted it at 1.008.

If you are aiming for something more in the middle of the style, I would up my initial strike maybe 2-3° F and mash for an hour. I also BIAB in a keggle, which is a giant heat conductor, so my temp losses are probably 10° F an hour in Chicago winters (at or near freezing in the garage).

If you have a quality burner, you can always turn it on very low and stir midway during the mash.

 

[kevin58]

I use a convert keg and have never insulated. I just use the burner to keep my mash temps in line.

 

[Piperlester]

I use a convert keg and have never insulated. I just use the burner to keep my mash temps in line.

I built a nice insulation wrap, but can't use it when the burner is on. My "challenge" is my burner is far too big for the size of kettle and keeping it low enough to just keep the temp warm usually results in it blowing out whenever a nearby squirrel farts.

 

[teeWRX]

Last brew day hovered around -7 to -10 Celcius for us, 2 layers of Reflectix insulation around the kettle and an old blanket over that kept the mash rock solid. I only aimed for 2 degrees (Fahrenheit) higher than and strike water calculator spit out to account for temperature lost during a really good stir at dough in. That being said 1 degree F higher would have been plenty as the temp barely dropped and I had to leave the lid off a little longer than needed to hit my target 153. We were using a 10gal SS brewtech pot. And I built a small brew pot sized "pallet" out of scrap wood I had lying around to get the pot up off my cold concrete garage floor.

 

[BigJoeBrew]

How about heat your strike water in garage, then bring into house, pour in grains and then insulate. Granted, this is only plausible if you feel comfortable with lifting the kettle. Also, you could heat to mash strike temp on Kitchen range and mash in house to avoid long distance carrying, plus you stay warm while heating strike water!