My efficiency is higher than I expected - BIAB

[Kluge]

OK, so I got excited reading the BIAB thread, and there was a sale on turkey fryers before Thanksgiving, so I decided to put down the extract and go for it - drilled a hole in the 30 qt. aluminum kettle, bought a ball valve and a pack of paint strainers, and boom! I'm brewing! My first batch came out of primary last week and is carbing. I wasn't too careful about my measurements, etc., but I thought that my efficiency was over 80%, which seemed unlikely. My second batch (today) I was more careful. I was using 8 lbs of 2-row and a half pound of Caraaroma for some color and body. I started with about 6 gallons of water, and ended up with about 5. I wasn't too careful about the temperature while mashing (probably dropped from 153 down to about 145 an hour later, and then stalled for a while at about 160-165 on the way mashing out at 170.) I squeezed the bag a little but no sparging.

I was shooting for a 1.047 OG based on what I thought was an optimistic 75% efficiency estimate, but after cooling the sample I took at the end of the boil to about 70 degrees it read 1.053, which works out to 85% efficiency. I figure it's more probable that I'm figuring something wrong than that I'm actually seeing 85% efficiency with my slap-dash techniques, but I don't know what it is. I'm trying to make a session beer so I guess I can just add water, but that seems, oh, I don't know - wrong?

I'd like to hit the OG I'm aiming for. Any ideas?

 

[thadass]

I've done 4 BIAB batches now and average 80-85% on mash efficiency. Since most recipes are geared to 70ish%, I enter them into BeerSmith and scale them to my efficiency. It's worked beautifully. The first two batches I winged it and measured my results but the last 2 I did the re-calculation and hit the target OGs almost spot on.

In general, using BeerSmith, it applies the efficiency conversion straight to the base grain and does some minor changes to the specialty grains to keep the color consistent, but it doesn't seem like that's incredibly necessary.

Seems like just adjusting your base grain appropriately would get you what you want. Assuming a recipe is written for 70%, you'd just multiply the base grain by 70 and then divide by 85.

 

[Porchfddler]

http://www.biabrewer.info/ it has a spreadsheet calculator which I find is spot on for getting your numbers right.

 

[RM-MN]

I usually only get about 80% efficiency BIAB unless I do a modified sparge which raises the efficiency up to 85%. Now that you have done one you also know that you can plan on higher efficiency for your nest batch and adjust the recipe or water quantity to hit your target OG.

 

[Kluge]

Thanks. I guess this falls into the category of "pleasant surprises."

So, if I want to dilute it to session beer ABV levels, do you recommend that I do so before pitching the yeast (I'm doing no-chill, so I haven't done so yet) or at the end of the primary?

 

[inhousebrew]

Nice! here's to buying slightly less grain. or to having slightly stronger beer!
I only hit about 75% with a no sparge but I like it because it's less work. I suppose I could change my crush or sparge but then I would have to change my crush or sparge,