temperature stabaliization in kettle during mash

[jonny24v01]

This is my second BIAB batch. I did my own cream ale, i'll post results later.
-8lbs 2 row
-1lb flaked maize
-0.5lbs honey malt
-0.75lbs crystal 15L
-0.25lbs flaked oats

1oz cascade(60 min)
1/2oz cascade(5min)
1/2oz cascade whirlpooled in
+1/2 whirlfoc and some yeast nutrient near the end
White labs 001 with a half liter starter(i get really fresh yeast from my supplier)

I used biab calculator to get my water volumes and strike temperature. At the end i adjusted, as per my setup for the next batches, that my grain absortion is 0.08gal/lb and my water boil-off rate is 1.4 gal/hr. The default values left me with 6.75 gallons pre-boil. So i boiled it down a little before adding hops

Anyhow, to the point now. My 1st batch, i had a decent size temperature drop during the mash even in 85 degree weather and stirring periodically. This batch i put 4 layers of reflectix insulation around my ss brewtech 10 gallon gallon and wrapped a wool blanket around it. The temp didnt drop a degree for 10 mins when i started my mash at 153 degrees, then i stirred. After another 20 mins it was down to 146 degrees. I took the lid off and stirred again. I applied the heat on nearly the lowest the bayou classic jet burner would go for about 5 mins and stirred and it was at 152 degrees. 15 mins later(45 min into mash) it was down to 145 degrees. I stirred and it came up to 150 degrees and i let it finish.
I have not been doing a sparge cause hitting the target gravity is not an issue especially with how fine the grains i get are. I figure i wont need to apply heat at all and just stir every 15 mins if i use a smaller volume of water and add sparge water over the grain to get to my 6.5 pre-boil volume. However with a smaller volume of water there would be more air space in the kettle. Would it be in my best interest to use about 2 qts/lb of grain and do a sparge to get to the correct volume of water or just insulate a little more and stir every 15 minutes

 

[tofuguy]

Have you tried a batch without stirring? I have to think the uncovering and pulling heat from the bottom to the top is what is getting your drop in temp. I only did one BIAB before jumping into recirc eBIAB, but that one batch I left it alone with only a blanket covering the pot on the stove and only saw a couple degree drop over 60 minutes.

 

[Beesnbeer]

I used to stir and had the same problem as well as poor efficiency. I quit stirring except at the beginning and the end of the mash and my problems resolved themselves.

 

[jonny24v01]

I stir to equal out the temp from top to bottom. Im not sure how necessary it is. My temperature probe starts at 4 gallons, so the bottom is going to be a couple degrees warmer

 

[wilserbrewer]

Do you check temps with a stick hand held thermometer?

I've heard of less than reliable results w kettle mount?

I stir and check with a digital hand held and without much insulation I don't get large temp drops like your reporting.

How large is your kettle?

 

[Seattle2k]

I periodically lift the grain bag and let the bulk of the wort drain. Then, dunk, pull, dunk. Check temp again, then flame-on, if it's low. My OG comes out perfect every time. I brew in weather cooler than 85F..usually more like 65-70F ambient air temps, no kettle insulation...just bare lid. I've never had a drastic temp drop...but then again, I keep checking my temps and adjusting.

 

[madscientist451]

When you get tired of the temperature swings, get a round cooler, add a spigot and put your BIAB bag in that. After you mash in, lay a piece of foil on the top of the mash, put the lid on and go do something else for an hour.

 

[Inkleg]

I stirred at first with the same results. Now I trust BeerSmith to calculate the temperature numbers for me. Like @madscientist451 said, Mash in, lay foil on top to lessen the dead space between the mash and lid, insulate the pot and just walk away. It also helps if your blanket reaches the ground. I brew at my LHBS a few times a year and people are always amazed at how steady the temperature remains.

 

[jonny24v01]

Its been hot lately. Im making another brew tommorow. Im going to stir it at the beginning going for around 150-152 degrees to start the mash. Wrap my 4 layers reflectix, wool blanket on the lid and an extra thick moving blanket draped completely down the kettle. Then at the end, i'll stir and see what the temp is on the kettle mount and use a probe thermometer too. Maybe opening it up several times is unnecessary. It sure does drop heat in a bbq when you lift the lid for any length of time. This time im also trying a water adjustment to the RO water ive been using to add a little bit of minerals and lower my mash PH a tad. One of my favorite things about BIAB brewing is that my local homebrew store has good pricing on grains and fresh yeast. My ingredients are costing around 10 bucks less a batch

 

[wilserbrewer]

I have noticed that it takes more time and more stirring for the grain to fully absorb all the heat, say 3-5 minutes and a couple good stirs.

What I have observed is if you mash in quickly and take a temp, you are imo getting a false high reading which in turn can be thought to be temp drop, when it is actually the mash stabilizing.

I suggest mashing in, stirring well for say a minute, cover the kettle and let rest a few minutes then stirring very well again and checking your temp at several locations in the mash.

Then insulate...

Imo I would start a little high to anticipate some temp drop at 152 or 153, as 150 does not leave much if any room for a several degree temp drop. With a 4 degree drop, 152-148 is preferable over 150-146 imo

 

[balrog]

I have noticed that it takes more time and more stirring for the grain to fully absorb all the heat, say 3-5 minutes and a couple good stirs.

What I have observed is if you mash in quickly and take a temp, you are imo getting a false high reading which in turn can be thought to be temp drop, when it is actually the mash stabilizing.

I suggest mashing in, stirring well for say a minute, cover the kettle and let rest a few minutes then stirring very well again and checking your temp at several locations in the mash.

Then insulate...

Imo I would start a little high to anticipate some temp drop at 152 or 153, as 150 does not leave much if any room for a several degree temp drop. With a 4 degree drop, 152-148 is preferable over 150-146 imo

This. It's my method too. Temps will stabilize after dough in but it is not instantaneous. It will take dialing in your system unfortunately, but this. Dough in, then lid on, reflectrix on, blanket on and wait 5 minutes. No touchy. Then open lid and stir and measure with long probe several places all over. Then lid on, wrap blanket and go sit on your hands for an hour. No peeking. No touchy. Go read a book, keg your last batch, chase small furry woodland critters, whatever. At mash end, stir to equalize any temp stratification, and measure throughout the entire volume again.

 

[jonny24v01]

Im always looking at ways to improve the beer, while still keeping it relatively simple. If my SG are on point, is their any flavor improvements of doing a sparge even if its just dunking it in a bucket of strike temp water. At the current time, i am brewing a batch about every three weeks. But i may have to brew more often to keep up. I just checked my cream ale from last batch after 6 days at 64-68 degrees and its about 1.014 FG, i'll transfer in a couple more days. I've been having good results leaving beers in the fermenter for 10-14 days.

 

[jonny24v01]

I just finished the 60 minute mash and stirred at the beginning for 3 minutes. Then i covered and let sit for a couple minutes and stirred again. After the 60 minutes it went from 152 to just over 150 degrees. My other thermometer read 1 degree higher than the fermentap kettle mount. Looks like all that insulation and waiting for the grain to heat up works

 

[RM-MN]

I just finished the 60 minute mash and stirred at the beginning for 3 minutes. Then i covered and let sit for a couple minutes and stirred again. After the 60 minutes it went from 152 to just over 150 degrees. My other thermometer read 1 degree higher than the fermentap kettle mount. Looks like all that insulation and waiting for the grain to heat up works

Do you know why you mashed for 60 minutes? I limit my mash to 20 to 30 minutes. You had to double or triple what I use for a mash period.

Reasons to mash for 60 minutes include poor milling of the grain so it takes more time for the starches to gelatinize or using grains with low conversion ability. Many people do a 60 minute mash in BIAB because that is what you use in a conventional mash tun where the milling of the grain must be coarser to avoid having problems with draining the tun. With BIAB you can mill much finer since you have a bag with much more filter area and that finer milling gets you quicker gelatinization and thus faster conversion.

 

[brew703]

I have the same issue- this past Saturday I brewed and had a 8 degree temp drop. I too stir every 15-20 min which I know plays a part in temp drops. I turned on the heat to bring it back to mash temp.

Next brew I'll stir good at the beginning and let it ride then stir at the end. May opt to just get a cooler and another bag and mash that way.
I also insulate with insulated jacket- may have to get welding blanket or large sleeping bag so that it touches the ground.

 

[jonny24v01]

I used 4 layers of reflectix insulation with 2 on the lid. A wool blanket on the top and a moving blanket draped completely over it. It worked great.

Im waiting on the cream ale to finish now. I transferred it after 10 days. It started at 1.052 and ended at 1.014. I cant wait to try it with it done. It is tasting very similar to cali creamin. Got to wait till about the end of the month or so.

 

[porterguy]

I have the same issue- this past Saturday I brewed and had a 8 degree temp drop. I too stir every 15-20 min which I know plays a part in temp drops. I turned on the heat to bring it back to mash temp.

Next brew I'll stir good at the beginning and let it ride then stir at the end. May opt to just get a cooler and another bag and mash that way.
I also insulate with insulated jacket- may have to get welding blanket or large sleeping bag so that it touches the ground.

Iuse a largesleeping bag. It works great