Mash temp drops

I use a boilermaker pot for my MLT, which is good for holding the mash temp for about 35 to 40 minutes. If I start at 156 after that amount of time it is usually down to 152. Should I add some heat and stir to get it back up or is it best to let it sit. What is an acceptable temperature drop over the 60 or more minutes.

Thanks

I recently started using a Boilermaker. After seeing the temp drop (due to the thin-walled Boilermaker) I started reserving a quart or two of strike water in another pot kept just below a boil (simmering). I use this extra water to adjust/maintain the temp. Just this past weekend I wrapped a huge beach towel around it and it made a big difference.

It will probably vary depending on your mash schedule but letting the temp drop vs. keeping it stable will affect the fermentability of your wort (if everything else is kept equal).

Most of the starch conversion happens within the first 10-15 minutes.
The rest of the mash time is just to make sure it's complete before boiling.

Back when I used a 7.5 gal aluminum pot for my MLT, I wrapped it in a sleeping bag during the mash, which meant I only lost 1 degree over an hour. 1 degree is considered by most to be "good". 4 degrees in 40 minutes is considerably more than most are comfortable with, but you'll still make beer....

HairyDogBrewing said:

Most of the starch conversion happens within the first 10-15 minutes.
The rest of the mash time is just to make sure it's complete before boiling.

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That's only true at high-ish mash temps where the alpha-amylase is working quickly.

4 degrees in 40 minutes is considerably more than most are comfortable with, but you'll still make beer....

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And it may be better than if the mash temp didn't drop. It should only affect the fermentability of the wort and however you achieve that goal is all good. Everybody has to adjust things for their system.

SpanishCastleAle said:

And it may be better than if the mash temp didn't drop. It should only affect the fermentability of the wort and however you achieve that goal is all good. Everybody has to adjust things for their system.

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I could be wrong here, but it was my understanding that it could affect conversion/efficiency too.

Say you dough in and are at 156. At this temp, you are starting to denature the beta, and the alpha is doing a lot of work. But, then you drop down to 152 before conversion is complete. Now, the betas are denatured, (they don't "renature"), but it's too cold for the alphas to function effectively. So, you can end up with unconverted starches, and things suffer...

shortyjacobs said:

I could be wrong here, but it was my understanding that it could affect conversion/efficiency too.

Say you dough in and are at 156. At this temp, you are starting to denature the beta, and the alpha is doing a lot of work. But, then you drop down to 152 before conversion is complete. Now, the betas are denatured, (they don't "renature"), but it's too cold for the alphas to function effectively. So, you can end up with unconverted starches, and things suffer...

Click to expand...

But it will eventually convert. I was going on the assumption that the brewer would ensure conversion (I guess I figured that was a given).

And if you start a rest at 156* F it should be fully converted fairly fast anyway. I agree that outside of 'reasonable' temp drops all bets are off.

I've always mashed in a pot and just let the temp drop and, once I had the system dialed in, could always acheive whatever fermentability I wanted and when I use Kaiser's Efficiency Calculator my conversion efficiency is right at 98%-99%. But with this new Boilermaker I'm still 'dialing it in'. My FGs have been as much as 2 points off target...unacceptable.

coolers are cheap!