Hi all,

According to Brewfather, I hit 90% mash efficiency at the end of my latest brew day. I exclusively do full volume/no sparge BIABs.

To me, this number sounds abnormally high given the fact most people are pulling around 70-80% mash efficiency using full volume BIAB. The question is: how common is this? My previous two batches have been varying around 69% to 76% of mash efficiency, and I'd rather have a consistent and predictable efficiency every single time. The only thing different in this batch was that I ordered the grain from another vendor who offered the option for a double crush (which I opted for) - apart from that, the process is the same. Can the difference be this dramatic when it comes to crush level?

FWIW, here is my process:

- I ordered the grain with a double crush.

- I heated 25 liters (6.6 gal) of mash water to strike temp, doughed in, hit 65c (149f) and kept it there for 60 minutes.

- I insulated the kettle by wrapping it in a reflective sleeping mat and a sleeping bag.

- I stirred every 15 minutes in hopes of increasing conversion and keeping temps uniform within the kettle. During the 60-minute period, I experienced a 0.5 Celsius degree drop in the mash temp, which I compensated by pulse heating the kettle back to 65c.

- After 60 minutes, I pulled out the grain bag, rested it on an oven rack that sat on top of the kettle, and I squeezed the bag using a kettle lid.

After the mash, I boiled for 30 minutes and here are the parameters that I ended up with:

Boil volume: 24 liters

Pre-boil gravity: 1.057

Post-boil kettle volume: 22 liters

Original gravity: 1.060

Grain absorption: 0.22 liters per kilogram

Boil-off: 4 liters per hour

Mash efficiency: 90.87%

Fermenter volume: 21 liters

And here's the grist:

76% 2-row - 3.6kg (7.94lbs)

15% Munich I - 0.7kg (1.5lbs)

7% Dextrin (Carapils) - 0.3kg (0.66lbs)

2% Caramel 30 - 0.1kg (0.22lbs)

Total: 4.7kg (10.36lbs)

Final gravity sits at 1.013 (estimate was 1.012).

According to Brewfather, I hit 90% mash efficiency at the end of my latest brew day. I exclusively do full volume/no sparge BIABs.

To me, this number sounds abnormally high given the fact most people are pulling around 70-80% mash efficiency using full volume BIAB. The question is: how common is this? My previous two batches have been varying around 69% to 76% of mash efficiency, and I'd rather have a consistent and predictable efficiency every single time. The only thing different in this batch was that I ordered the grain from another vendor who offered the option for a double crush (which I opted for) - apart from that, the process is the same. Can the difference be this dramatic when it comes to crush level?

FWIW, here is my process:

- I ordered the grain with a double crush.

- I heated 25 liters (6.6 gal) of mash water to strike temp, doughed in, hit 65c (149f) and kept it there for 60 minutes.

- I insulated the kettle by wrapping it in a reflective sleeping mat and a sleeping bag.

- I stirred every 15 minutes in hopes of increasing conversion and keeping temps uniform within the kettle. During the 60-minute period, I experienced a 0.5 Celsius degree drop in the mash temp, which I compensated by pulse heating the kettle back to 65c.

- After 60 minutes, I pulled out the grain bag, rested it on an oven rack that sat on top of the kettle, and I squeezed the bag using a kettle lid.

After the mash, I boiled for 30 minutes and here are the parameters that I ended up with:

Boil volume: 24 liters

Pre-boil gravity: 1.057

Post-boil kettle volume: 22 liters

Original gravity: 1.060

Grain absorption: 0.22 liters per kilogram

Boil-off: 4 liters per hour

Mash efficiency: 90.87%

Fermenter volume: 21 liters

And here's the grist:

76% 2-row - 3.6kg (7.94lbs)

15% Munich I - 0.7kg (1.5lbs)

7% Dextrin (Carapils) - 0.3kg (0.66lbs)

2% Caramel 30 - 0.1kg (0.22lbs)

Total: 4.7kg (10.36lbs)

Final gravity sits at 1.013 (estimate was 1.012).

Last edited: