BiaB repeatable efficiency

[azazel1024]

I haven't done too many BiaB sessions yet. 4 now total.

My efficiency is improving as I am getting my technique down. However, it still seems pretty all over the place.

My first try with a 2.5G batch ended up at 68% efficiency. My next one, a wheat beer (which may have made a difference?) ended up at 78% efficiency. The next was 62% efficiency. My last one was 70% efficiency.

One of the things I know I need to do is get equal sized pots. I am doing batch sparge. I mash in my 32QT pot with generally around 75% of my total water. After a 60 minute mash which I usually shoot for 154F start temp (which drops to around 146F by the end of an hour in my pot), mash out at 165F. Then I drain the grains, squeeze out what I can and transfer to my smaller pot (20qt) with the rest of my water at 165F. I let that soak for about 15-20 minutes, drain, squeeze out what I can and then transfer the smaller pot to the large one and bring it up to a boil.

I would of course love to get my efficiencies higher, but I care more about repeatability in it. Makes it hard to repeat a recipe, or even do a good job planning it if my FGs are going to be 20+% off and have to play with boiling longer (which can be a lot of boiling 20% off) or dilluting, which both also mess with my IBUs.

It would be nice to be able to get efficiencies within about 3-4% repeatable (so within about 10% of the same FG each time, same recipe).

 

[Oginme]

Couple of things from someone who has a number of BIAB under my belt:

First if you are not grinding your own grain, do so. If you are getting your grains milled at your LHBS or an on-line supplier, request that they be double milled or specially milled for BIAB. My efficiency was all over the place as well until I got my own mill. Now they are consistently around 86%.

Second, divide your water up as evenly as possible between mash and sparge. This seems to give me the most efficiency.

Third (OK, I lied, there's more that a couple...), I would be looking to stabilize your mash temperature. I mash in on the stove to get the mash temperature I want. I pre-heat the oven at the lowest possible setting. My oven has a warm setting which is supposed to be 160F, but actually measures around 170F. Place the covered mash pot in the oven, close it up and turn the heat off. At a mash temperature of 149, my ending temperature after one hour is around 150F. At a mash temperature of 156F, the ending temperature is around 155F. The range of 152 to 154 is the same coming out.

Make sure you check for conversion at the end of one hour with a iodine/starch test.

Hope this helps!

 

[241]

Water volume is also a huge part of efficiency. Make sure water volume is consistent across batches.

 

[wilserbrewer]

Water volume is also a huge part of efficiency. Make sure water volume is consistent across batches.

Yes, excellent point! Especially with small volume batches, a small variation of a quart or two is a large percentage!

 

[azazel1024]

Okay, great. Thanks guys.