Very high efficiency on last batch

[guinsu]

Yesterday I brewed a sort of English brown ale/light brown porter and when I measured my gravity it was much higher than expected, BeerAlchemy gave me 95% efficiency. Post boil gravity was also higher so it wasn't just one bad reading.

When I was mashing in I screwed up the temp calculation and the mash ended up at 144F, so I boiled some more water and got it up to 154F (my target). The mash sat at 144 for about 20 minutes, then at 154 for an hour. I am wondering if either the rest at 144 or just the very long mash is what helped my efficiency. The recipe used 8lbs of Muntons 2-row, a pound of crystal and then a smattering of some darker grains but there wasn't anything unmalted or non-barley in there.

My refractometer could be out of calibration, I am planning on testing that this weekend, I didn't think at the time to grab the hydrometer and compare since I was on a tight schedule.

Just trying to figure out what I did because if I am going to end up with with a 9% instead of a 6.5% beer I'd like to plan for it

 

[Reustonium]

what was your OG?

Looking at the recipe and assuming you collected 5.25G of wort, you should be around 1.060, which would seem more in line with your expectations.

Are you confident in your wort volume? Did you measure this volume at sparge temperatures or room temperature? There is an expansion factor which should be taken into account if measuring wort volume at higher temperatures (but it is not a huge factor).

Also does your refractometer have auto-temperature correction?

 

[guinsu]

My OG was 1.072, however I also added a pound of turbinado to the boil. The software said I should end up with 1.059. Pre boil was 1.048, software said 1.038. Preboil volume was measured at mash temp, post boil was measured at 68F. I know there is a 4% expansion but I don't think that is throwing it off that much. Refractometer has ATC.

When I transfer to secondary I'll test it with the refractometer and dig up the hydrometer.

 

[Beerbuck]

Pre boil at 1.048 sounds good for a final og of 1.060

 

[guinsu]

The thing is the preboil was supposed to be 1.039, not 1.048. According to the software that is 95% efficiency, I am trying to figure out how I got that if indeed I did.

 

[Sawdustguy]

You will probably get a thinner beer. What happened is almost what I would expect. Mashing lower does lend itself to extracting more sugars but that comes with a price. You loose a little body especially if the grain was well modified.

 

[guinsu]

Ah that makes sense. I'll have to keep that in mind next time I want to thin out a big beer without having to add sugar or anything like that. Actually that method would be perfect for my Christmas Ale.