Confusion over OG for Boneshaker clone

[coolmug]

Hi,

I brewed a clone of Boneshaker, and am also trying to get a high gravity ABV (10-11%). I added 8 cups of dextrose and used 2 packets of Safale US-05 dry ale yeast. The OG was 1.06, which seems quite odd considering the amount of extra sugar in addition to the enzymes in the brew. Previously, my OG of the last batch (same recipe) was also 1.06 but I only added 4 cups of dextrose. FYI, the ABV of that batch was 7.88% after 14 days or so of primary fermentation with only 1 packet of yeast. I understand the FG should be lower this time because I'm using 2 packets of yeast, but why would the OG still be 1.06 with all that sugar I added this time?

This is the recipe I followed (with the exception of the yeast amount and extra dex):

Beer Specifications:
SRM: 12
IBU: 65
OG: 1.066
FG: 1.016
ABV: 6.7%
Pre-Boil Vol: 6.85 gal
Post-Boil Vol: 5.5 gal
Adjust for 75% Mash Efficiency



Grain Bill:
8 lbs UK Pale Ale Malt
3 lbs US 2-Row Malt
1 lb 8 oz German CaraMunich III
10.5 oz UK Wheat Malt


Hop Additions & Times:
26 g US Chinook @ 60 Min.
10 g US Chinook @ 50 Min.
10 g US Chinook @ 40 Min.
10 g US Chinook @ 30 Min.
28 g US Amarillo @ 15 Min.
28 g US Amarillo @ Flame-Out


Yeast Addition:
US-05, White Labs WLP001 or Wyeast 1056


Cheers,

 

[VikeMan]

Sounds like you added about 2.5 pounds of dextrose (a little bit of a guess...sugar should be measured by weight, not volume), which in 5.5 gallons of wort would yield about 20 points. Since your OG (post-boil, I assume) was 1.60, that means you got ~ 40 points from your grains. With your grain bill, this suggests a mash efficiency of about 44%, which would be remarkably low. So, a couple questions to start:

- Was your post boil wort actually 5.5 gallons measured?
- How finely were your grains crushed?

ETA: I just noticed your wording: "I added 8 cups of dextrose and used 2 packets of Safale US-05 dry ale yeast." When did you actually add the dextrose?

 

[coolmug]

Ah yes it would have been likely 3.5 lbs of dextrose (in this batch, not the previous one I mentioned).

To answer your questions, the post boil wort ended up being closer to 6 gallons, so that may have had an effect. I'm not too sure about the fineness of the grains, as they came pre-milled. They were more of a cracked look rather than fine or powder-like if that's what you are wondering?

Dextrose was added at the beginning of the boil.

Cheers

 

[VikeMan]

To answer your questions, the post boil wort ended up being closer to 6 gallons, so that may have had an effect.

It certainly would have. 1.060 in 6 gallons would have been ~1.065 in 5.5 gallons:
60 x (6/5.5) = 65.45

I'm not too sure about the fineness of the grains, as they came pre-milled. They were more of a cracked look rather than fine or powder-like if that's what you are wondering?

Homebrew stores are notorious for coarse crushes, which reduces mash efficiency.

 

[coolmug]

Ahh OK good to know, thanks for the help! Last question then; in regards to the coarseness of the grains, could I simply extend the mash time or would it be better to grind them up further with my food processor?

 

[VikeMan]

Last question then; in regards to the coarseness of the grains, could I simply extend the mash time or would it be better to grind them up further with my food processor?

Extending the mash could help a little.

Personally, I wouldn't use a food processor to "mill" grains. You really don't want to shred/pulverize them. Crushing is the way to go. Some options:
- get your supplier to use a smaller mill gap
- get your supplier to run the grains through the mill twice
- get your own grain mill

Also, what was your mash temperature, and how did you measure it?

 

[coolmug]

I see. I'm doubtful my supplier would change their milling for me, but it's worth a shot. If not, I'll have to look into getting a grain mill then. The mash temperature was 65 celcius; I used a large floating thermometer.