BIAB temp issues

[SDJay]

First BIAB last night, a MW Heffeweissen. (Have done 10 extract batches and one partial mash) I have a 10 gallon Blichmann kettle, and the thermometer was off calibration by 12 degrees, so I ended up mashing for 60 mins at actual temp of 141. When I discovered the error using my thermometer for my sparge water, (which I didn't need because I hit volume pretty close), I extended mash time by 30 minutes at 152. Hit my target post boil gravity of 1.052. It is bubbling like crazy this morning. Any thoughts on what I can expect from this? A new, random way to step mash? I plan to get a digital, easy to calibrate thermometer with my next order. Extremely frustrating considering the pain in the a** the protruding kettle thermometer probe is when using the bag & wort chiller!

 

[josh-h]

I think the beer will be fine. As long as you got conversion and hit your gravity. Way better to be under mash temp than over. And I second the blichman thermometer issue. I'm considering removing it and using the hole for a rims build.

 

[WoodlandBrew]

It might come out a little thinner than you planned, but I wouldn't worry about it. you might be interested in a couple of posts on my blog. Search for "thermometer calibration" and "mash temperature"

The information is better organized and better tied together in my book that will be published next month.

 

[1MadScientist]

Good save on the temperature.

That's a nice thermometer. I would keep it in and calibrate it at mash temp not boiling. Also you can check the temp with another thermo at the top, I use a 12" lab thermo. You will get different readings because of the bag, dial thermo outside of mash bag. I use the dial thermo as a judge for direct firing during the mash. My mash temp is based on my lab thermo. Both thermos will eventually read the same.

With a tampered bag, my bag has never got caught on the thermo probe.

2nd Bag Design by Mad Scientist Brewhaus, on Flickr

 

[LLBeanJ]

I'd expect it to finish a few gravity points lower due to the extended time in the low 140s making for a higher wort fermentability, so a little dryer than expected and a little more %ABV. Should still be a nice beer.

 

[SDJay]

One week in the bottle, and it turned out to be as good, or better than my extract Heffeweizen.