So I've just completed my fifth BIAB brew, and this time I decided to try and calculate the mash efficiency of my setup since I'm fairly sure it's not as high as it should be. I also think at the moment its the most useful efficiency measure, but I'm not sure!
I tested the wort after the mash and after putting it into the fermenter to get gravity readings.
The readings were 1.020 after the mash (67C), and 1.030 into the fermenter (~25C).
The recipe for this brew is here: http://brewerschoice.com.au/little-cheapers-pale-ale-2/
To determine the post-mash gravity, I plugged the values into this calculator and got this:
I then plugged the recipe and this gravity reading into this calculator (approximating the recipe as close as possible) to get this result:
34 litres was my strike volume - I'd estimate the volume post mash was probably more like 32 litres, and I think my keggle has about a 3L trub, which when accounted for brings the calculated efficiency down to 67%.
- Am I doing this right?
- Is mash efficiency the usual measure people quote?
- What can I do if the gravity is too high or too low pre-boil?
Any assistance is greatly appreciated!