Pitch More or Let it Be? High-Mashed Brown Ale

[Andrew82]

I brewed a brown ale just about two weeks ago.

OG = 1.060
SG (10/7) = 1.021

10 lbs VIenna
1 lbs Caramel 60L
1 lbs Victory
12 oz Special
2 oz Chocolate

Yeast = 1 11.5g sachet of US-05.

I mashed around 156, although it erred a bit higher at times, for 60 minutes. Expected FG is 1.016 according to Beersmith.

Is it worth pitching another packet of US-05? Or should I just cut my losses and package?

 

[VikeMan]

I mashed around 156, although it erred a bit higher at times, for 60 minutes. Expected FG is 1.016 according to Beersmith.

The one thing BeerSmith doesn't take into consideration when predicting Attenuation/FG is grain bill. Your grain bill is not particularly fermentable. I put your specs into BrewCipher, and got an FG prediction of 1.018 (for a 156F mash) and 1.019 (for a 158F mash, since you indicated it went higher). My guess is your attenuation is about as done as it's going to get, or nearly so. If the FG doesn't change in a few more days, I'd package.

 

[Holden Caulfield]

I put your specs into BrewCipher, and got an FG prediction of 1.018 (for a 156F mash) and 1.019 (for a 158F mash, since you indicated it went higher)

I have endeavored to model FG, but ran into a wall when I thought through all the variables that have to be considered for a comprehensive model and the lack of data on many of the variables.

1. Attenuation range of the yeast
2. Mash temp - impact curve above 150, impact curve below 150
3. Mash time
4. Mash type: single infusion, step, decoction
5. Grain bill: % crystals, % kilned, types, lovibond, adjuncts
6. PH of the mash

I would greatly appreciate hearing how you approached it. Also, I understand if you want to keep it a secret .

 

[VikeMan]

I would greatly appreciate hearing how you approached it. Also, I understand if you want to keep it a secret .

I'm happy to talk about my approach. The actual formulae are hidden, password protected, and proprietary.

Attenuation range of the yeast

Greg Doss' data is useful here. And for the strains not tested (e.g. White Labs strains), consider using the same data for equivalent/close strains.

Mash temp - impact curve above 150, impact curve below 150

Mash time

Look at Gregg Doss' and Kai Troester's data.

Mash type: single infusion, step, decoction

I only truly modeled single infusion, because that's the data that's available. I added step mash to my sheet, using some unproven assumptions, but I wouldn't claim to be very accurate for step mashes.

Grain bill: % crystals, % kilned, types, lovibond, adjuncts

See Doss' data, notice the relationships between certain grain characteristics and results, and extrapolate to grains that he didn't test (or in a few, do some fermentability experiments of your own).

PH of the mash

I ignored pH. Troester found some relationship, but within the normal target pH range, there's not enough difference to be useful. Or at least that's how I originally felt.

 

[Holden Caulfield]

Thanks VikeMan! Simplification and going with what is available is good advice.

I have read through most of Troester's analysis but have not delved into Doss' data. Looks like I have some reading to do.

 

[Andrew82]

Thank you for your response! I figured it might be done given the temperatures and grain bill, and your analysis has confirmed it.