Unusually High Mash Efficiency

[crispylopez]

I recently moved into all-grain and upgraded my system by building a 10-gal cooler tun. Last night I took it for my first spin around the block and got a crazy high efficiency (128??), resulting in a MUCH higher anticipated ABV than I'd planned.

I've got my big fermenters tied up, so thought I'd use the Mr. Beer fermenter that came w/ my first kit to do a little experimenting on a smaller scale (I decided to play w/ a combination of only fruity AU/NZ hops and also try my hand at harvesting Dupont yeast to go along w/ a vial of WLP565).

Here's the nitty gritty...

Grain Bill (3.5lb total):
-3lb Pilsen
-3oz Vienna
-3oz Crystal 10
-2oz Crystal 120
-8oz Pilsen DME*
-8oz Corn Sugar
-1/4 tsp. Yeast Nutrient
*originally designed recipe for 2 gal and decided after to make it 2.5 (adding DME along w/ sugar during boil to bring gravity up)

Strike Water: 1.3 gal at 154F
Sparge: 2.7 gal at 172F
Target Batch Size: 2.5 gal
(Actual Batch: 2 gal)

Mashed at 148F for 60min. Recirculated 3x. Added sparge water and allowed to sit 10min, then drained and boiled for 60min.

That's about it. If anyone has any idea what I did to overextract, please let me know. Not terribly concerned about this recipe, it was a small batch and if I can dry it out sufficiently, who cares that the ABV is high, right? If not, I'll just call it a Belgian Strong Ale.

Oh, for anyone wondering, the hops consist of Galaxy, Wakatu and Nelson Sauvin, using a smidge of Galaxy for bittering and relying almost exclusively on late additions for the rest for an estimated 28 IBU. There will also be a combined 1oz of the three going to dry hop in secondary.

 

[crispylopez]

Btw, 154F is a typo. Strike water was 158, and dropped to 148 w/ the grain in the tun (I wanted to mash low to help get it dry...which now I'm hoping more than ever).

 

[doug293cz]

There's no way you got over 100% efficiency. What were your pre-boil volume and SG, and the post-boil volume and SG? Are you sure the weights on your ingredients were accurate (I know my LHBS scale gives out about 10% more wt than indicated [ie it reads low.]) Were either the sugar or DME late or post-boil additions?

Brew on

 

[crispylopez]

Yeah, I know that it's not technically possible. That's my problem.

The preboil is the 1.040 (1.038, adjusted for temp). And the OG/postboil SG was 1.084. I added DME and dextrose just before the start of the boil, after taking my preboil reading.

I was w/ them when they weighed my grain at the LBHS, and they didn't weigh out more. Unless the scale was off.

 

[doug293cz]

Yeah, I know that it's not technically possible. That's my problem.

The preboil is the 1.040 (1.038, adjusted for temp). And the OG/postboil SG was 1.084. I added DME and dextrose just before the start of the boil, after taking my preboil reading.

I was w/ them when they weighed my grain at the LBHS, and they didn't weigh out more. Unless the scale was off.

Can't figure efficiency with SG's alone. Also need to have corresponding volumes.

Brew on

 

[crispylopez]

I know. Unfortunately, I didn't get an exact measurement of what went into the kettle because the pot doesn't them. I've got notches I made every .5 gal on my paddle when submerged in my kettle.

Of the 4 gal that went into the tun (1.3 gal strike + 2.7 gal sparge listed above), under 4 went in, but not as little as 3.5 gal. Gun to head, 3.6-3.7 gal. Which boiled down to 2 gallons (a lot to boil off, I know...got a new burner too and I guess I ran it too hot).

Thanks for your help. Much appreciated.

Cheers!

 

[EJay]

I know. Unfortunately, I didn't get an exact measurement of what went into the kettle because the pot doesn't them. I've got notches I made every .5 gal on my paddle when submerged in my kettle.

Of the 4 gal that went into the tun (1.3 gal strike + 2.7 gal sparge listed above), under 4 went in, but not as little as 3.5 gal. Gun to head, 3.6-3.7 gal. Which boiled down to 2 gallons (a lot to boil off, I know...got a new burner too and I guess I ran it too hot).

Thanks for your help. Much appreciated.

Cheers!

How do you know what efficiency you got? What numbers did you plug into what calculator?

 

[crispylopez]

I plugged the numbers into the BrewersFriend and HomeBrewing online calculators. All they ask for is wort collected, gravity and grain bill.

 

[crispylopez]

Thanks, btw

 

[doug293cz]

2 gals @ 1.084 nets out to 168 total gravity points achieved. You put in 45 points worth of sugar + DME, so you got 123 gravity points from your grain. Your grain bill had a potential of 128.15 points (@ 100% eff), so your efficiency looks like 123/128.15 = ~96%. That is probably an unrealistic number (but at least not impossible), so I suspect you had more grain than you thought, and/or less volume.

Brew on

 

[crispylopez]

Hmm. Either one is possible. My method for measuring volume is so spotty at this point. I'll need to prioritize a better kettle w/ markings whenever I can do it. And I suppose the scale where we weighed could be off too.

I also put the recipe together going off 70% efficiency. I know it takes a few before you can really get a feel, but I'm thinking I should go off a higher estimate for my next batch and see how it shakes out. Idk, 80, maybe?

Any thoughts on my mashing times and recirculation, think maybe I overdid that? I was just trying to be thorough, but I could see how recirculating 3 times and letting sparge sit on the grain bed for 10 min could overdo things. Still, people fly sparge just fine, right?

Thanks again. I really appreciate you taking the time to help me out b

 

[Yooper]

Hmm. Either one is possible. My method for measuring volume is so spotty at this point. I'll need to prioritize a better kettle w/ markings whenever I can do it. And I suppose the scale where we weighed could be off too.

I also put the recipe together going off 70% efficiency. I know it takes a few before you can really get a feel, but I'm thinking I should go off a higher estimate for my next batch and see how it shakes out. Idk, 80, maybe?

Any thoughts on my mashing times and recirculation, think maybe I overdid that? I was just trying to be thorough, but I could see how recirculating 3 times and letting sparge sit on the grain bed for 10 min could overdo things. Still, people fly sparge just fine, right?

Thanks again. I really appreciate you taking the time to help me out b

It's hard to tell what your efficiency was, as the crucial part (volume) is missing. I would guess that even 80% is a bit too high of a guess, but who knows?

The other thing is that your preboil may have been inaccurate as well, if you didn't cool the sample to under 100 degrees or so as any sample over 100 degrees would be inaccurate. If you cool the sample to 90 degrees, and then use correction software for the reading, it is probably pretty close but at mash temperatures it's not usually even close.

You can't really get a high efficiency by recirculating, as that won't increase the diffusion (the principle by which sparging works).

 

[doug293cz]

Not sure what your crush looks like, but @RM-MN and others have shown that 30 minute (and even shorter) mashes work well with very fine crushes (coarse flour.) If you have a more traditional crush, then you may need to stick to longer mashes. 10 minutes is not too long to let the sparge sit. You should stir about 5 minutes, let sit for 10 - 15 minutes, stir again, and then drain. The time sitting allows for sugars to diffuse out of the grain particles. The larger the particles, the more time that takes. Some people recirc mashes continuously, so 3 recircs is not excessive.

To get a good handle on efficiencies, you need to have accurate grain weights and volume measurements. Get yourself a digital scale. I have started re-weighing what I buy at my LHBS because I know their scale is not accurate (now I have to figure out what to do with small amounts of left over grain; maybe a "garbage" brew.) The easiest way to measure volumes is with a dip stick calibrated for your pot.

Brew on

 

[crispylopez]

Yooper, I didn't cool my preboil sample, so that may be off for sure. Still, my OG I get right before pitching yeast, so that was at 70F.

Doug, I actually have marked my paddle to the volume in the kettle, but I realize now I was also measuring by marking in the cooler too...can't have helped reading it in two places. I'll look into the scale. Sounds like a good idea.

Thank you both!