Yesterday's brew session yielded what I'm pretty sure is a 94% efficiency. At first I was excited, but after thinking about it, I'm not sure this is ideal. I ended up overshooting the Starting Gravity. So, I'm looking for some advice or thoughts on this process.
I'm using BIAB to mash my grains and I'm limited to a 7-gallon turkey fryer pot. But, I have been able to manage just fine despite the limited kettle size. Here are the numbers for this brew session:
Recipe - Reaper's Mild
5.5 lbs Simpson's Maris Otter Crisp
1.5 lbs C60
.4 lbs (6 oz) Chocolate Malt
Total grain weight - 7.4 lbs
Since I'm doing a 5.5 gallon batch, I could not do a full BIAB due to kettle space limitations. So, here is how I brewed:
Step 1: Mashed the full grain amount in a mesh bag in 6 gallons of water at 158 F for 1.5 hours.
Step 2: heated 1.5 gallons of water to 176 F in a second pot, pulled the wet grain bag out of the 6 gallon mash, drained and dunked it in this second pot for a 10 minute mash at 170 F. Pulled the bag, drained and squeezed.
Step 3: I added the 1.5 gallons of mash-out-wort to the main boil kettle and stirred it all up. I ended up with 6.75 gallons of wort I took a sample for a gravity reading, cooled it to 60 F and it came in at 1.038.
Plugging these grains, wort volume and gravity reading into The Brewer's Friend Brewhouse Efficiency Calculator and into Beersmith, I come up with 94% efficiency! Here is the online calculator I used:
Step 4: At this point, the wort is all the way to the top of my boil kettle. Too much for this pot to handle! So, I removed one gallon and set it aside. Boiled the rest for 30 minutes to cook off some, then added the gallon back into the pot. Then finished out the boil for one hour following the hop schedule as usual.
I ended up with 5 gallons of wort for pitching at 1.047 Starting Gravity. Reaper's Mild recipe calls for 1.038 SG.
Here are my two questions:
1. How can I adjust this mash method to lower efficiency? Just add water to the final wort before pitching yeast to get a lower SG?
2. I wonder if I can do two beers using this method, sort of like a partigyle? The "main mash" is one beer. Dunking the grains in a second pot of water would yield the second, lower gravity beer. I have not heard of anyone doing this BIAB, but I might experiment with it, to see what happens. The second beer would most likely be a very small volume in yield.