Also increasing efficiency

[UltraHighABV]

Hi guys; just finished my first real brew, and my efficiency was much lower than anticipated. Here's a detail of my protocol....

14.75lbs grain, at 1.25q/lb;

-Heated up 4.5 gallons of water to 175F; added to my 10 gallon home depot MLT.
-Overshot mash temp to 163F
-added ice and a small amount of cold water, got it to 151F in about 3-4 minutes
-mashed for 90 min at 151F; temp was 150F after 90 min. I stirred and took the
temp every 30 mins

-Recirculated wort, recovered 2.7 gallons to boil pot

-Added 4 gallons 184F water to grains
-Stirred, temp was on the nose 170F
-Waited 20 min
-Stirred, recirculated wort
-recovered 3.9 gallons to boil pot

Got a 1.050 from the 6.6 gallon wort (at room temp); calculated efficiency was 61%.


Any ideas on why it was so low? My temps seemed right on the money and everything went really well without hangups except for the initial mash temp overshoot.

Thanks guys!

 

[doug293cz]

Hi guys; just finished my first real brew, and my efficiency was much lower than anticipated. Here's a detail of my protocol....

14.75lbs grain, at 1.25q/lb;

-Heated up 4.5 gallons of water to 175F; added to my 10 gallon home depot MLT.
-Overshot mash temp to 163F
-added ice and a small amount of cold water, got it to 151F in about 3-4 minutes
-mashed for 90 min at 151F; temp was 150F after 90 min. I stirred and took the
temp every 30 mins

-Recirculated wort, recovered 2.7 gallons to boil pot

-Added 4 gallons 184F water to grains
-Stirred, temp was on the nose 170F
-Waited 20 min
-Stirred, recirculated wort
-recovered 3.9 gallons to boil pot
1
Got a 1.050 from the 6.6 gallon wort (at room temp); calculated efficiency was 61%.


Any ideas on why it was so low? My temps seemed right on the money and everything went really well without hangups except for the initial mash temp overshoot.

Thanks guys!

Your grain absorption + MLT dead space loss is 4.5 - 2.7 = 1.8 gal or 1.8/14.75 = 0.122 gal/lb (actually not quite that good due to the ice and "small amount" of additional water.) This is a typical value for a traditional MLT, so no problem there.

That points a finger at your conversion efficiency, meaning it appears you did not convert enough of the available starch to sugar. Since your temps were good, that leaves crush, mash stirring, and mash pH as your most likely issues leading to your low conversion efficiency. So, some questions:

1. Did you crush your own grains, or did the grain supplier do it?
2. Do you know the mill gap setting used for crush?
3. How much did you stir during mash in? Are you certain you didn't have any dough balls?
4. Didi you stir well before initial run off?
5. Did you stir your sparge water in aggressively?
6. Do you know your water profile, and did you do any salt additions to adjust mash pH? Did you measure your mash pH (at room temp)?

You should get in the habit of measuring and recording your first run off SG. This value is essential for calculating your conversion efficiency. And you need to know if the problem is incomplete conversion, lautering inefficiencies, or wort volume losses elsewhere that are causing your low efficiencies.

Brew on

 

[UltraHighABV]

Awesome, thanks for the reply this is just what I was looking for.

1) Crushed my own at the brew store in a large mill
2) No, I just flipped the switch and poured them in
3)I stirred once every 30 minutes, for a total of 4 stirs (final stir at time 0); I stirred thoroughly, making sure to get all the stuff up from the bottom. I assume a dough ball is a large clump of grain?, I didn't see any large clumps of grain
4) can't recall; but I did stir at time 0, so probably yes
5) I stirred the sparge water in, I would say my stir was equal to all previous stirs
6) My girlfriend lost the pH paper, so I couldn't measure it unfortunately. I don't have a water profile.

So it seems it could be either pH, water ion concentration, or inefficient grinding. I don't think stirring was an issue.

What mill setting should I be using? Is it okay to just run the grains 3-4 times through for a total grind?

I'll try to get some water values from the city tomorrow and report back, thanks

Your grain absorption + MLT dead space loss is 4.5 - 2.7 = 1.8 gal or 1.8/14.75 = 0.122 gal/lb (actually not quite that good due to the ice and "small amount" of additional water.) This is a typical value for a traditional MLT, so no problem there.

That points a finger at your conversion efficiency, meaning it appears you did not convert enough of the available starch to sugar. Since your temps were good, that leaves crush, mash stirring, and mash pH as your most likely issues leading to your low conversion efficiency. So, some questions:

1. Did you crush your own grains, or did the grain supplier do it?
2. Do you know the mill gap setting used for crush?
3. How much did you stir during mash in? Are you certain you didn't have any dough balls?
4. Didi you stir well before initial run off?
5. Did you stir your sparge water in aggressively?
6. Do you know your water profile, and did you do any salt additions to adjust mash pH? Did you measure your mash pH (at room temp)?

You should get in the habit of measuring and recording your first run off SG. This value is essential for calculating your conversion efficiency. And you need to know if the problem is incomplete conversion, lautering inefficiencies, or wort volume losses elsewhere that are causing your low efficiencies.

Brew on

 

[doug293cz]

Awesome, thanks for the reply this is just what I was looking for.

1) Crushed my own at the brew store in a large mill
2) No, I just flipped the switch and poured them in
3)I stirred once every 30 minutes, for a total of 4 stirs (final stir at time 0); I stirred thoroughly, making sure to get all the stuff up from the bottom. I assume a dough ball is a large clump of grain?, I didn't see any large clumps of grain
4) can't recall; but I did stir at time 0, so probably yes
5) I stirred the sparge water in, I would say my stir was equal to all previous stirs
6) My girlfriend lost the pH paper, so I couldn't measure it unfortunately. I don't have a water profile.

So it seems it could be either pH, water ion concentration, or inefficient grinding. I don't think stirring was an issue.

What mill setting should I be using? Is it okay to just run the grains 3-4 times through for a total grind?

I'll try to get some water values from the city tomorrow and report back, thanks

Yes dough balls are clumps of grain in the mash. They don't get wet, so the grain in them might as well have been left out, as it contributes no sugars to the mash.

Many people run thru the mill twice to improve the crush and minimize the number of uncrushed kernels. More than twice thru the mill is probably a case of diminishing returns, and not worth the trouble. A mill setting of 0.032" is used by many people, although lots of BIABers crush much finer as they don't have to worry about stuck sparges. One thing to be aware of is that wheat kernels are much smaller than barely kernels, so need a closer mill gap to get cracked open. Uncracked kernels pretty much don't convert in the mash.

The 90 minute mash would normally take care of small deviations from optimality of crush or pH, so things may have been way off here. Or, your high temp excursion went higher or longer than you thought, and denatured a lot of your amylase enzymes.

Brew on