7 Malt Black Stout Yeast Experiment

[AKnewbrews]

I brewed a 2 gallon batch of an AG stout recipe I concocted over the last couple months. It consists of 7 different malts/grains/adjucts of British pale, flaked oats, chocolate malt, flaked barley, roasted barley, Black Patent, and black barley. I hopped it with an oz of Columbus and an oz of Northern Brewer for 60 minutes.

I ended up boiling down 6 gallons to 2 gallons over the course of 4 or 5 hours and ended up with 1.625 gallons. My volume measurement device needs to be calibrated, obviously! Besides that, I ended up with 73% efficiency with an average of 1.134 OG. I say average because I split this batch into two 1 gallon batches, the first half out of the kettle reading 1.133 OG and the last amount from the kettle reading 1.135 OG. I split these into 2 batches to use 2 different yeast. I want to see the difference in the beer between the Wyeast 1028 London Ale and the Wyeast 1272 American II Ale.

It ended up being a good thing that I cam short about 3 cups of a gallon for each "gallon" batch I made because if they were a full gallon, i would be afraid the headroom in the jugs would not be sufficient for fermentation.

Anyways, I hope to try this out after bottle conditioning this winter. Approximate ABV is around 11.5%

I can't imagine how I would get a full 5 gallon batch of this made without horrible efficiency unless I was to have 10 gallons of wort after sparge and boil out 5 gallons of it. my equipment isn't up to that task at the moment.

 

[GryphonBrew]

Sounds sexy as hell to me.

 

[AKnewbrews]

Just transferred these two test batches into 2 secondary containers until I figure out if I want to just bottle or leave them in secondary for a little while.

I measured final gravity for both, unfortunately I am not 100% sure Which one has which yeast in which due to my labeling getting rubbed off somehow.

The one I believe is the London Ale yeast had a final gravity of 1.066. I thought that was too high, but then I calculate out ABV and it comes in at 9%. It was very chocolatey, like a bittersweet chocolate, but also an obvious roasted malt character as well. Very thick, you could feel the thickness in your mouth. No hot alcohol flavors present.

The other that I think is the American Ale II had a final gravity of 1.058, ABV of 10%. It did not have the chocolaty taste that the other had. It very much lacked the chocolate and was more pronounced in the roasted malt area. I would say it was a bit more balanced in bitterness with a warm, butterscotch-like aftertaste. It was visibly thinner in viscosity and felt so in the mouth. A little bit of alcohol in this one, but still smooth.

Do you think I under pitched or had a yeast issue and that both of these batches should have attenuated out more? I made a starter for both, but it may not have been quite large enough. They were only 0.8 gallon batches though.

Considering that the American Ale I, the 1056, does very well, I am guessing that this yeast better fermented the sugars. I have not had the best of luck with the London Ale and I believe that the 1.066 FG batch is because of this yeast.

Suggestions, comments?

 

[hoppymonkey]

Did you oxygenate well? That is a mean brew for any yeast to chew through.

 

[Calder]

I really don't think I could drink anything that sweet. 1.066 is like dissolving 1.5 lbs of sugar in a gallon of water, or about 2.5 ozs of sugar in a 12 ozs glass of water. Or about 2 lbs of honey in a gallon, or 3.5 ozs of honey in a 12 ozs glass.

My wife went to a local beer tasting (commercial), and someone had a keg of HB (Oktoberfest I think), so she bought home a glass for me. I tasted it and it was way too sweet for me - undrinkable as far as I was concerned. I poured it into my hydrometer jar to check it, and it measured 1.032. I don't know why this guy was giving away samples, I would have been embarrassed to give that to anyone.

I think your yeast is done; probably due to a combination of high alcohol and high osmotic pressure, and you may still have a lot of fermentables. How are you planning on carbing in the bottle? Using any different higher strength yeast will almost certainly get further fermentation with potential bottle bombs.

 

[ksbrain]

In fairness the ofest had a much lower OG. Though I'd want a lower FG myself, I think these two might be OK, especially since it's less than a gallon each.

But I do agree... good luck bottle conditioning!

 

[AKnewbrews]

I thought 1.066 was going to be sweet too, but at 9% ABV and a good dose of chocolate and roast grains, I found them anything BUT sweet. My last amber came out sweeter than these did.

The batch at 6 gallons was around 1.040 if I remember correctly. At 0.8 gallons, it should not require a ton of yeast compared to if it was a 5 gallon batch. I made a starter for each yeast.

At the same time, 1.066 and 1.058 are both very high gravities, which means there are probably a lot of dextrins that cannot be fermented. I ended up mashing a little high with some decent temperature fluctuations, so this may have something to do with the high gravity.

I am going to bottle condition for 6 months and try one. Then I'll wait until next year and see how it turns out. It's going to be a patience brew! Maybe next winter's treat.

 

[emjay]

If the yeast did a good job attenuating, then there's no reason for it to be sweet.

It's a very common misconception that high mash temps will create a sweeter beer. That's simply wrong. It adds body, and lowers the ABV potential, but does not increase sweetness.

What does mash temp have to do with this? Well, if the yeast properly attenuate, then they will leave behind the more complex sugars/dextrins, which are unfermentable. The misconception seems to stem from the fact that there are more of these sugars left in the beer, and sugars are thought of as sweet. But these complex sugars have very little if any sweetness at all. So it sounds like your yeasties did a good job of eating up all the more easily fermentable (and as it happens, sweeter) sugars.

But... this is a good example of why beers like this should be mashed low. Russian Imperial Stouts, for instance, tend be pretty thick and big-bodied beers, and so many people (especially newer brewers) take that as a sign that the beer ought to be mashed at a high temperature, like you'd see in a lower-gravity stout. But if you look at most highly-proven RIS recipes, they don't typically have mash temps as high as one might expect. Because the fact is, with such a high-gravity beer, even if you mash pretty low there will still be MORE than enough unfermentables to provide the nice, thick body you'd expect from an RIS, while not being so over-the-top as to affect drinkability.

So yeah... it's almost definitely the mash temps which caused the beers to finish alarmingly high, but they appear to have attenuated fine. Personally, I prefer to keep my grain bills simple, but if you do this one again, try mashing around 150, or 152 at the most.

 

[AKnewbrews]

That all makes a lot of sense emjay, and I did shoot for a high mash at 158, which ended up fluctuating from 150 to 165 degrees. I think it averaged around 156 for the duration of 45 minutes.

It has such a great flavor, so I am no unhappy with the results. After all, they are test batches. If you have ever had the Ten Fidy, the viscosity is of that consistency of the 1.066 FG beer. With carbonation, I can imagine it being quite good.

 

[buckeye2011]

Test batches that you won't drink for at least a year? You have more patience than me!

 

[AKnewbrews]

Haha, I will probably base a larger batch off of how these taste in 6 months. What else do you do with something like this, blow 100 bucks on a batch that ends up crap after you wait for a year for it to condition?

I do have a lot of patience....