# Mash Efficiency?

### Help Support Homebrew Talk:

#### redd1982

##### Well-Known Member
How many gallons of water should I use for a grain bill of 16 lbs.? May seem like a dumb question, but I am have had efficiency problems in my last 3 brews (my average efficiency is 62%). I have been using Sparge Pal, and its not helping. Thanks in advance!

#### gcdowd

##### Well-Known Member
What is your target pre boil volume? I assume 0.12 gallons per pound for absorption.

#### mdgagne

##### Well-Known Member
1.25 qt/lb is my go-to grist ratio

#### branCHEs

##### Well-Known Member
Everyone has their own system and you will have to figure out what works best for you equipment.

For my mash tun, I use 1.5 quarts of water per pound of grain. There are 4 quarts in a gallon.

I drain my mash tun. Then I measure how much wort I have. I then take the difference between my wort and my pre boil volume and use that volume for my sparge water. Since the grains should be fully saturated, what ever you add for sparge should drain out giving you you exact pre boil volume.

Hope this helps!

#### gcdowd

##### Well-Known Member
I measure all my water before hand, rather than measuring first runnings then calculating the sparge water. I find that using 0.12 gallons per pound of absorption gets me close enough so that i can measure out my mash and sparge water before hand. I aim for 7.5 gallons of pre boil wort, so in your case you would need 9.42 gallons to get 7.5 gallons pre boil:

16 lbs x 0.12 gallons per lb = 1.92 gallons lost to absorption

7.5 gallons + 1.92 gallons = 9.42 gallons

OP

#### redd1982

##### Well-Known Member
Makes complete sense. Thanks for the help! In total, I was only using approx. 8.25 gals of water (see the attached picture). My numbers are "all over the place". Hopefully I don't screw up the IPA I plan to make Saturday.

#### rklinck

##### Member
Are you ending up with the right amount of preboil volume? If not, why not add some more sparge water? I fly sparge and always heat a lot of extra water just in case. Even if you batch sparge, I would think you could have the water ready and if your volume ends up short, you can do a second batch sparge with however much additional water you need.

Just as an FYI, I don't think you should expect to get great efficiency with a 16 pound grain bill for a 5 gallon batch. For my 9 pound grain bills, I routinely get 85% efficiency. I made an imperial stout with 19.125 pounds of grains and ended up with 70% efficiency. There was just not enough sparge water to really rinse the grains well.

OP

#### redd1982

##### Well-Known Member
What would happen if I cut the grain size down to 9 lbs.? Would that screw up my recipe?

#### rklinck

##### Member
9 lbs of grain is my average grain bill. It gets me an OG of around 1.050. That's a beer with about 5% ABV depending on attenuation.

OP

#### redd1982

##### Well-Known Member
I cut my grain bill down to 13 lbs., and ended up with an OG of 1.081. I am looking at 76% efficiency (so far), and an ABV of 8%.

PS - I know "I over did it on the corn sugar". This was a test batch to get everything running smoothly again.

#### rklinck

##### Member
Is the recipe you posted wrong (it is still showing a 16 lb grain bill)? Assuming that you actually used 10 lbs of 2-Row, my calculations show you got 66% efficiency from the grain. The 2 lbs of sugar contributed 90 gravity points (or 18 points per gallon), meaning that you would have had an OG of 1.063 from the grain alone. According to BeerSmith, that equates to 66% efficiency.

#### amandabab

##### Well-Known Member
big grain bills like that are where decoctions start making sense and become worth the huge PIA and extra time, if you don't want to take a big efficiency hit.

you move grain in and out at each temp rest and the mash tun becomes a big enzyme tank.

OP

#### redd1982

##### Well-Known Member
Yes, the image was posted incorrectly. Sorry about that...it was an old screen shot. Good idea to just disregard that.

OP

#### redd1982

##### Well-Known Member
amandabab said:
big grain bills like that are where decoctions start making sense and become worth the huge PIA and extra time, if you don't want to take a big efficiency hit.

you move grain in and out at each temp rest and the mash tun becomes a big enzyme tank.
How large are your average grain bills? I am still new to all-grain brewing, and only using a 5 gal mash tun. I could use any info at this point. What base grains give you the best efficiency? I am a bit confused about that.