Mash efficiency is equal to conversion efficiency times lauter efficiency. Sparging improves lauter efficiency by rinsing more of the sugars (created by conversion of starch to sugar) out of the spent grain mass. It is possible to calculate conversion efficiency and lauter efficiency if the needed data items are collected during the brew day. The required data are:
- Strike water volume
- Grain bill weight
- Grain bill potential (weighted average of all grains used, can use 80% or 37 ppg if you don't have detailed data)
- Grain absorption rate (if draining completely after sparge)
- SG of wort in mash immediately prior to draining
- Pre-boil volume
- Pre-boil SG,
- Post-boil volume
- Post-boil SG (OG)
The calculations can be done using
this spreadsheet. If your lauter efficiency is better than the theoretical efficiency for a single batch sparge, with all run-off volumes equal, then you are doing a good job of sparging. If not, then you should look at just doing a simple batch/dunk sparge instead of your current process (if you care about improving your efficiency.) Of course, what
@madscientist451 says above is also a valid choice. It's all about what's important to you.
Brew on