Biab Mash Temp Problems

[Kwitty]

So this was my first biab two days ago. I have a Maris Otter/Simcoe smash IPA. My temps throughout were always a bit low (150-154). I started the burner when it hit 150 and kept it low. I stirred every few minutes but the mash rose slowly. I killed the flame 5 minutes before lifting the bag out to drain, & just hit 154. After the bag was out I took another temp and it was 164! Guess there was water below the grain not being stirred in, but didn't think of that at the time. With a 75 minute mash my O.G. hit 1.070. I was aiming for 1.057. The higher gravity is ok for the IPA I'm making but I don't know why it happened. I assume the temp? Is it a problem? Do I need to worry about off flavors? Thanks for any help, and Happy Easter!

 

[monkeyman1000]

Let me start by saying I am no expert. Does your bag completely fit your pot. I suppose if the bag is sitting off the bottom of the pot then the water under the grain with heat more than the water above the grain. The grain will act as a heat block, from what I've read on here. Hopefully someone smarter than me will chime in.

 

[Kwitty]

It does reach the bottom but I had an up side down colander on the bottom to keep the bag from melting during heating. I also kept the bag from being slack so it couldn't make it to the edge of the colander. So what you're saying makes sense. I just hope it didn't make enough difference to screw things up! The high O.G. has me concerned. Did it result in something bad? I guess time will tell. Just hope it wasn't a total waste!

 

[soccerdad]

Not sure how your fermentable sugars will be effected by the possible high temp, but just wanted to say that i have read that adding heat when mashing in the bag is best done in short bursts. I try to do that .. add heat, stir, gather the top of the bag, bounce it up and down a few times to move water around, kill the heat. It seems to move things that 1 or 2 degrees that i need.

 

[RM-MN]

It does reach the bottom but I had an up side down colander on the bottom to keep the bag from melting during heating. I also kept the bag from being slack so it couldn't make it to the edge of the colander. So what you're saying makes sense. I just hope it didn't make enough difference to screw things up! The high O.G. has me concerned. Did it result in something bad? I guess time will tell. Just hope it wasn't a total waste!

Whooo boy does it ever result in something bad. Your level of alcohol will be higher than you planned and as a result you will get drunk much easier on this batch.

Other than that, there is nothing wrong with the higher OG, it's happened to me a few times when I brewed a recipe that was intended for a 70% efficiency and with BIAB I hit about 85% efficiency. If your grains were well crushed your conversion was done well before you added the heat so all you did by heating the wort was increase the amount of sugars that could be dissolved in the wort. Now quit worrying and start planning the next batch and see if you can get that kind of efficiency again. If you can do it consistently, you can scale your recipes to 85% instead of 70 (software and computers make this so easy).

 

[Kwitty]

I guess my biggest concern was off flavors from the grain at the bottom getting too hot. The alcohol I can live with! But you're right if this works and I can reproduce that efficiency, it will be a money saver.

 

[RM-MN]

I guess my biggest concern was off flavors from the grain at the bottom getting too hot. The alcohol I can live with! But you're right if this works and I can reproduce that efficiency, it will be a money saver.

Since your grains were in a bag surrounded by wort they couldn't get hotter than the boiling point of the wort, just like you would have if you were doing a decoction. That shouldn't cause any off flavors.

 

[PRE66_6TART]

You might get less fermentable sugar from the grain at the bottom where the temp was hotter. That combined with the higher OG might result in your beer being sweeter than you wanted. Maybe, maybe not.

I've given up on trying to maintain my mash temps by applying heat, because I have similar issues with uneven heat distribution and end up bouncing up and down trying to get it to stabilize at the right place. So I just focus on insulating the pot instead. I know some people do it without problems though, I just don't bother with it anymore. I have a slightly different setup than most people though.

 

[Kwitty]

Thanks everyone for the input. Guss I'll just have to tweak my process until it's dialed in. Can't wait to see the results, good or bad. Either way I learn something!