RISky Business (Looking for answers!?!)

[LouieMacGoo]

A few months ago our HBC bought a 52 gallon Four Roses Bourbon Barrel and after some discussion we decided to fill it with a Russian Imperial Stout recipe (see below). Today (Sunday) me and another club member (John) brewed the last 10 gallons that we needed to fill the barrel and we both fell well short of the projected OG of 1.099 and we're not sure why but we have a suspicion of what might be the cause. Allow me to share the details.

I finished first and my OG ended up being 1.076. John finished up about an hour or so later with an OG of 1.079! Both of us brewed 5 gallons batches, we both bought the all the grains, hops and yeast from Adventures in Homebrewing on the same day (Saturday) about 2 hours apart and after talking we found that the same person helped us with our purchases. I did the recipe in my usual BIAB fashion starting with 7 gallons of water to which I added the grains to but rinsed the grain bag into my brew pot once I finished the mash to get as much sugar from the grains as I could and bring the pre boil volume up enough to make sure I had 5 gallons of wort left after the boil.

John brewed the same exact recipe, grain bill and all in the traditional 3 vessel All Grain method. Neither of us experienced issues while brewing. We both used our refractometers to check the OG of our batches. When he failed to hit his OG we started digging in a little deeper and we rechecked the OG with our hydrometers, which confirmed the 1.070ish OG readings. Just to make doubly sure I grabbed my distilled water and we both re-calabrated our refractometers. Both were just slightly off but not enough to change our OG readings significantly.

John has brewed this very same recipe several times before and never had any issue hitting his OG numbers. After our re-checks and confirmation that our refractometers and hydrometers were accurate we came to the conclusion that the grain scale at Adventures must be about 2 lbs off, causing both of our grain bills to less than the nearly 21 lbs of grain of the original recipe.

What do you think? Am I missing something? Could it be something else?

RIS Recipe specifics:

Style: Imperial Stout
Batch size: 5.0 gal
Boil volume: 6.0 gal
OG: 1.099
FG: 1.025
Bitterness (IBU): 92.4
Color (SRM): 62.2
ABV: 9.7%

Grain/Sugars:

17.00 lb Two-row (US), 81.9%
1.50 lb Roasted Barley, 7.2%
1.00 lb Special "B" (Belgian), 4.8%
0.75 lb Chocolate Malt, 3.6%
0.50 lb CaraPils, 2.4%

Hops:

4.00 oz Challenger (AA 7.2%, Pellet) 60 min, 70.6 IBU
2.00 oz Kent Golding (AA 5.8%, Pellet) 30 min, 21.8 IBU

Yeast/Misc:

California Ale yeast

[Beer-lord]

I've got no clue Leigh except that I really have trouble getting higher than 1.080 using BIAB and I've read many others have the same problem without doing extra work. But that doesn't explain your friends problem.
Are you sure you got the correct weight of grain from Adventures?

[LouieMacGoo]

Are you sure you got the correct weight of grain from Adventures?

The guy at Adventures measured out the grains for me as I watched and it appeared to be correct as he added the grain. John said he measured out his own grains. So we were thinking that the grain scale at Adventures was off by 2 pounds.

[Beer-lord]

I can see scales being off but if off by 2 pounds, that's sad. I wonder what it shows if someone ordered just 1 lb of specialty grain. You'd think they'd know they have a problem.

Did they crush it for you? How was the crush?

[LouieMacGoo]

Yes they crushed it, and it looked good. All the grain was pretty well broken up and there wasn't an excessive amount of flour in the mix.

[RickBeer]

Can't speak for the Adventures in Taylor, I go to the one in Ann Arbor. Although I haven't been there in some time (working through inventory), I measure my own grain and I always ensure that the scale reads 0 when I put the bucket on it. I also weigh each component separately, then mix them, to ensure I don't make a mistake.

I find it hard to believe the scale is off by 2 pounds. I find it easy to believe that someone hit TARE without a bucket on it, then put a 2 pound bucket on it, didn't notice it, and gave you 2 pounds less of the first grain. That is, if a 5 gallon bucket weighs 2 pounds. Yup - just Googled it. A 5 gallon bucket weighs 2 pounds...

[Inkleg]

Did you take a SG reading after the mash was complete? Like Paul said 1.080 can be pushing it BIAB, but doesn't explain your friends unless he had some channeling issues or like you said that you were short grain. After the mash readings could tell the tale.

On bigger beers I like to boil longer to evaporate more water helping raise SG. My RISs are at least a 90 minute boil and sometimes longer depending on refractometer readings.

[LouieMacGoo]

Did you take a SG reading after the mash was complete? Like Paul said 1.080 can be pushing it BIAB, but doesn't explain your friends unless he had some channeling issues or like you said that you were short grain. After the mash readings could tell the tale.

On bigger beers I like to boil longer to evaporate more water helping raise SG. My RISs are at least a 90 minute boil and sometimes longer depending on refractometer readings.

I did do a pre-boil SG and it was about 1.030 from what I remember. I was thinking that was low at the time but just continued with what I was doing. I don't know if John took a pre-boil SG or not. As for getting the 1.080 BIAB ceiling I have been able to get 1.095ish a couple of time with big brews but usually by starting with a lower mash volume and sparging the grains into the pot.

I think this one will go down as we'll never know for sure!

[D_Rabbit]

Louie,

With my new project in my basement going forward I have been diving in to PH and water profiles a little more. I just can't fathom a scale being off by that much. Where was the batch made? If he has made the batch before with his water with no issues did he make it at a different location with his setup?

My only thought would be a possible shift in PH levels which prevented proper conversion or grains not being crushed well enough.

[BlackDuck]

Brewing Considerations for High Gravity Brewing is an article that was just published (1/10/18) by Brad Smith of BeerSmith. It's an interesting read and may possibly shed some light on some of your issues.

[LouieMacGoo]

Louie,

With my new project in my basement going forward I have been diving in to PH and water profiles a little more. I just can't fathom a scale being off by that much. Where was the batch made? If he has made the batch before with his water with no issues did he make it at a different location with his setup?

My only thought would be a possible shift in PH levels which prevented proper conversion or grains not being crushed well enough.

This is a good thought however he brought his own RO water with him where as I used my tap water as I usually do.

[RickBeer]

Again, seems pretty simple to me. A 2 pound bucket is put on a scale that is not then zero'd out, so the grains are short by 2 pounds.