mash effiency

[bomberns127]

i posted a topic a while ago about the amount i get from sparging, and 1 reply mentioned mash effiency, checking online on how to do it, do you work out the sg at fermenting temp(20 -30deg) or temp of mash when sparged?
i have never worked out my effiency as i dont think it makes that much difference, does it?
how will knowing your effiency help the brew? what hints will it give to improve for next time?
im sure someone will tell me otherwise lol
if there is an easy way to work it out please can someone let me know
cheers people

 

[phettebs]

Well, one reason why you'd want to know your mash efficiency is if you are formulating recipes. Most recipes are calculated to hit a certain OG at a certain efficiency (around 75%). If your mash efficiency is say 58%, you will fall well under the expected OG. If you know this ahead of time, you can compensate by adding more grain or extract to make up the difference. This is exactly what I had to do when I first went AG.

You'd want to cool the wort sample down before taking the reading.