Better efficiency with less sparge water?

[Randar]

New to AG and had this problem with my last brew. I was trying to collect 12.25 gallons pre-boil and as I was sparging (fly sparge with a 75 qt rectangular MT) I felt like I was chugging along real well. But I was still collecting runnings in the 1.020-1.025 range but had already collected 13 gallons! I didn't want to have to boil off for 2 hours, so I cut it off at that point.

So, how do people get better extraction with the same volume? I did a 2-stage mash (alpha and beta rests) so before I even started sparging I had already had ~1.75 qts/pound of water in the MT. I volaufed a pretty significant volume as well (probably close to 5 gallons). My sparge took almost an hour so I don't think I was going too fast with my flow.

Suggestions? Recirculation? Grain bed too shallow?

 

[Bobby_M]

You were already thinned out so for most of the sparge you were simulating a no-sparge runoff. How much grain was it and what was the batch size?

 

[Randar]

You were already thinned out so for most of the sparge you were simulating a no-sparge runoff. How much grain was it and what was the batch size?

25.5 lbs of grain overall (mostly german munich) and the target batch size was 11 gal (target 80% efficiency was trying to collect 12.25 gallons of 1.059 wort and ended up with 13 gal of 1.052).

 

[Randar]

bump. Really no suggestions? Seems to me this would be a common problem.

 

[DrinkNoH2O]

So basically you ended up with with 13 gal of 1.052 when you wanted 12.25 gallons of 1.059?

Next time with the same grain bill use .75g less water, the sugar levels will remain the same and you'll have a higher gravity on the 12.25g yield.

 

[Randar]

You were already thinned out so for most of the sparge you were simulating a no-sparge runoff.

Are you saying that I should have thinned out my original mash-in to avoid having so thin a mash at the end of the Beta Sacch rest? i.e. it would have provided me with similar total extraction for less volume?

 

[Bobby_M]

No, I meant the first rest should have been much thicker.

25.5lbs of grain with like 25 quarts. Then you can make the move to your next rest with a small portion of boiling water. It would depend on where your two rest temps were but you should be able to make it with around 1.5qts/lb total before you start sparging.

I think this is a reason why decoction mashing or direct fire/HEX step mashing is preferred to pure infusion based step mashing.

Honestly, I've never done an infusion step mash so I can't convey my efficiency experience there.

 

[Randar]

No, I meant the first rest should have been much thicker.

25.5lbs of grain with like 25 quarts. Then you can make the move to your next rest with a small portion of boiling water. It would depend on where your two rest temps were but you should be able to make it with around 1.5qts/lb total before you start sparging.

I think this is a reason why decoction mashing or direct fire/HEX step mashing is preferred to pure infusion based step mashing.

Thanks Bobby. This was what I was looking for. I had seen a lot of references to starting protein rests with as little as 0.75 qts/lb but nothing really about Alpha/Beta rests (or any rest in the gelatinization temp ranges) doing the same with a really thick starting mash. Makes sense.

Direct fire sure seems like it has its benefits if you're into the 2 or 3 step mashes as you noted the lack of additional water required.