Ridiculously Low Efficiency

[Guidry]

Ok, switched over from "regular" all-grain to BIAB and I was getting ~70% that way. Today I did a BIAB brew and got 52%. Any ideas how that could happen? Other BIAB brews have been 70+%.

 

[C-Rider]

How was your crush? Do it yourself? I crush at LHBS and run my grain thru the mill twice.

 

[Guidry]

I mill it myself. Like I said, I haven't had a real problem with efficiency before, I've always been in the 68-75% range. I thought about it a lot last evening because it frustrated me and I may have found a possible cause.

This was a small batch BIAB (2.5 gallon batch). I've always used one of those paint strainer bags to hold the grain, but normally my grain was in the 3.75-4.5lb range. This time I had 5.75 lbs and I think maybe the bag might be a little small for that. Maybe the mash water could not flow well enough through it. I have a larger grain bill planned for the next one so I think SWMBO might be sewing up a bag for me.

[Off to look for example photos]

 

[Kozzer]

I was just going to ask how "tight" the bag is around the grain. In my first BIAB/partial mash, my grain bag was too small and I got terrible efficiency. But after that batch I got a much larger bag that allows me to stir freely inside the bag, to ensure all grains are properly soaked/rinsed and my efficiency hasn't been below 70% since.

 

[C-Rider]

I mill it myself. Like I said, I haven't had a real problem with efficiency before, I've always been in the 68-75% range. I thought about it a lot last evening because it frustrated me and I may have found a possible cause.

This was a small batch BIAB (2.5 gallon batch). I've always used one of those paint strainer bags to hold the grain, but normally my grain was in the 3.75-4.5lb range. This time I had 5.75 lbs and I think maybe the bag might be a little small for that. Maybe the mash water could not flow well enough through it. I have a larger grain bill planned for the next one so I think SWMBO might be sewing up a bag for me.

[Off to look for example photos]

I just mashed 6.36 lbs of grain in 3 gallons of water in a 5 gallon round cooler using a paint strainer bag. Plenty of room for the grain. I use the large bags from HD>

 

[Powerturn11]

I've mashed 12lbs of grain in a 5 gallon paint strainer bag in my 10 gallon kettle with ~80% eff. On a 60 mash I stir at beginning, .5hr, and at end. I'm not bragging at all just saying maybe something else is your problem.

 

[C-Rider]

What are you mashing in and how much water did U use? Did you mix it at all during the mash? Did you stir as you added the grain?

 

[Powerturn11]

What are you mashing in and how much water did U use? Did you mix it at all during the mash? Did you stir as you added the grain?

I mash in my kettle. I always mash with 6 gallons of water regardless of grain bill and then use 170 deg sparge water to bring up to desired pre-boil water. I squeeze bag hard after initial mash and after rinsing grain bag with sparge water. Yes I stir after adding grain, stir really good too. I also stir at 1/2 hr mark, and again at end.

 

[Powerturn11]

Will be making one small change in the future. I'm going to use 5 gallons instead of 6 for The initial mash. I don't boil off nearly what I think I will. A hard boil with my kettle I only boil off around .5 gallons in an hour.

 

[C-Rider]

I mash in my kettle. I always mash with 6 gallons of water regardless of grain bill and then use 170 deg sparge water to bring up to desired pre-boil water. I squeeze bag hard after initial mash and after rinsing grain bag with sparge water. Yes I stir after adding grain, stir really good too. I also stir at 1/2 hr mark, and again at end.

I vary my mash volumn according to my grain bill. You need to start at the "finnish"
1-how much you gonna bottle.
2-add trub loss in bottling bucket
3-add boil off loss
4-add trub loss in fermenter
5-add loss to grain

Now you have an idea how much strike water u need.

 

[SDJay]

I split the grain bill in to two bags to save on my arms/back, and "tea bag dunk" and stir a couple of times, and I usually hit my OG. I do 5 gallon batches using a 10 gallon Blichmann.