First eBIAB complete, now some questions.

[dfborn]

This weekend, I completed my first BIAB in my newly finished electric kettle. It's a 60qt Concord Kettle with a 5500 ripple element. The recipe was Northern's Bourbon Barrel Porter.

I hit the gravity of 1.065 on the recipe after milling the grain twice with my Corona mill (which was much messier than expected).

Here are my questions:

1.) The mash temp dropped much more than I expected. 30 mins in I lifted the bag and turned the element back on - it was in the mid 40s. I had the kettle wrapped in a blanket and was inside (71F) but that didn't seem to help much. I picked up some Reflectix to add to the kettle. Will that be enough to hold the temps, or should I look into getting a pump so I can recirculate the mash with the element on?

2.) I'm assuming that hitting Northern's OG isn't actually that great of efficiency, and I know that consistency is more important than increasing my efficiency as long as it's not terrible. However, is the Corona Mill going to be good enough for BIAB, my crush wasn't what I would call uniform. After the first time, there was a lot of flour but also some grains that were completely uncrushed. The second time through eliminated almost all of those. Do I need to go finer? Is there such a thing as too fine for BIAB (at least with what I can do with a corona mill)?

Thanks!

 

[RM-MN]

2. I don't think you can go too fine with your Corona mill. On mine, the milling plates rub together when there is no grain in there and if I tightened it up any more I wouldn't be able to turn the crank. With a finer milling of the grain, conversion is quicker and more complete so your efficiency goes up.

1. With the grains milled fine, your conversion will be done so quickly that the heat loss will be nothing to worry about. I've used iodine to test for conversion (when starch is present, a drop of wort on a drop of iodine and the mixture will turn dark blue) and found that it was complete at about 2 minutes. Complete conversion does not mean that you should stop the mash at that point as it takes longer to extract the flavors from any other grains but the temperature loss is less important then. From my experience with the short mash times, the least time I recommend would be 30 minutes to get the full flavor extraction.

 

[wilserbrewer]

Tighten up your corona mill, there should be no need to run through twice.

Perhaps strike a few degrees warmer next time. Also, you mash temp should be measured after thorough mixing and several minutes to allow the temp to stabilize. If you stirred and checked the temp immediately, you may get a false high reading in that the grain was still absorbing the heat of the strike water. It takes more mixing and time than one would think for the temp to plateau, maybe 3-5 minutes.

 

[TexasWine]

Is there such a thing as too fine for BIAB (at least with what I can do with a corona mill)?

Thanks!

I've found that the answer to this is, "it depends." I know you're not here yet, but if you ever go the route of recirculating with BIAB, there is a limit to how fine you can crush. You'll end up with a stuck mash if you go too fine.