will correct strike water vol get me improved efficiency

I'm 4 AG batches in and still refining my technique and numbers. Today reading How to Brew I realized the last two batches with 12.5lbs and 13.25lbs of grain were mashed in with well under the 1.33-1.5qt/lb ratio it seems alot of people use. I mashed in with 4 gal for both batches, collected 3 gal, mashed out with 1.25gal and sparged with 4 gal and collected my 7-7.25 gal pre boil. I've managed to hit my preboil gravity numbers via refractometer but I'm wondering if my efficiency would b better using the correct amount of strike water for my first runnings or maybe it wouldn't make any difference. Brewing this week and plan on trying 1.5qt/lb to mash in and c what happens. According to beersmith, I've plugged in some recipes I've already done and my mash efficiency was anywhere from 75-83% but my brewhouse efficiency was 68-70% due to boil off issues I think

 

I wouldn't say you were well under the 1.33-1.5 qt/lb that a lot of people use. Your last two batches were at 1.28 and 1.21 qts/lb, which is very close to what most folks do. I myself tend to do 1.5 because I find that thickness easier to work with. My advice is to try different rates between about 1.25 and 1.75 and see what you like.

It sounds like you're batch sparging, so the single biggest factor in your mash efficiency is going to be the size of your grain crush. If you mill your own grain, try adjusting the size of your mill gap and see what effect it has. If you mill too finely, you may encounter a stuck sparge, and if you mill too course, you'll see lower efficiency. If you get your grain milled at your LHBS, plan on whatever efficiency you get from it (and cross your fingers their gap consistent from batch to batch).

If you're getting different values for mash and brewhouse efficiency, it's likely due to losses in your system (losses to dead space, trub, hoses, chiller, etc.). If you have no losses, those two values should be the same. That is, a difference in those two values is independent of boil off rate.