Friday, May 4, 2012

Kentucky Common Reboot

After my last debacle I decided to give it another shot trying to brew up a Kentucky Common.  After my last beer developed intense hot vomit aromas I had to dump it out.  Luckily I dumped it out in my grass so that I was able to smell the wonderful aromas for quite some time!
This time around I decided to change a few things up.  I think one of the biggest issues in using raw grain as a source of cultures is that you really never know what your gonna get.  And its very likely that there are some enterobacter, butyric acid bacteria or other nasties living on the grain that will give it a nice garbage aroma and taste.  Luckily though those nasty type of bacteria are killed by lowering the pH, so once fermentation starts in most all of them die.  Well then you say, why did they ruin your last Kentucky Common? That's because the flavor thresholds for the compounds they produce are extremely low, so it doesn't take much time for them to leave a lasting impact on a beer.

A great way to avoid having to deal with them is by making a "starter" using raw grains to build up a culture to add to your beer.  The nasty bacteria may be present initially but if you dump off most of the starter and step it up 2 or 3 times the nasty flavors are gone and the bacteria are dead leaving you sacch, brett, and any lactic bacteria you may have grown up.

This was the approach I took to this beer, I'm hoping that the culture will end up much more sour that when I tried with the funky peach from a month back.  In this attempt I grew up the culture over a much longer time (~1.5wks) and added backing soda/chalk to buffer the acidity so the bacteria didn't die. Other than that the only other thing I changed in this go around was to do a no boil batch, and added mash hops to make up for not boiling.  Hopefully these changes will give me a nice sweet/sour beer that is an easy drinker relatively quickly.  Worst case I dump it out again (though this time I'll use the toilet to get rid of it)

Kentucky Common Reboot
Malt Bill
Amt (lbs)Type
6.25Pilsner
2.0Flaked Corn
1.0Caramunich
1.0 ozRoasted Barley
Hops
Amt (oz)TypeTime
0.75EKG (5.1%)Mash
Mash Schedule
TempRatioTime
152F1.1qt/lb45
170F1.7qt/lb15min - vorlauf
YeastGrain Culture + Nottingham(3days later)
Stats
5.5galOG1056
92% effIBU7
No BoilFG
Notes: So this ended up being quite a bit higher OG than I had anticipated.  I planned on getting worse than normal efficiency because I wasnt running off as much wort.  Somehow I managed to get about 5% better than I normall do, so this one ended up quite a bit higher (~10pts):  The mash smelled amazing with the hops in there, I might have to do that again soon!



7 comments:

Jeffrey Crane said...

I tried a similar technique with the grain culture that was written about in a Zymurgy article a year ago or so. It didn't work so well, but making multiple steps makes sense to promote the lacto, sacc and Brett.

More recently in Chad's interview on the Brewing Network he talked about his spontaneous beer (Petite Sour) and how he got tons on butyric acid. The interesting part is that Brett can metabolize that and turn it into the fruity ester - ethyl butyrate (flavor agent for pineapple) - http://www.math.unl.edu/~jump/Center1/Labs/CarboxylicAcidsandEsters.pdf.

The other thing he mentioned that he will do for future batches (you as mentioned)is to lower the mash pH to less than 4.5 before running it off into the fermenter if doing a no-boil method as this will kill the bad bacteria.

I'll be interested to hear your results.

Ryan said...

Ive heard his petite sour, the guava one I believe, actually had a lot of cheesy flavor/aroma. so while brett may metabolize some, it doesnt seem to do it all, which to me still would ruin a beer

maybe with more culturing he'll get it to work all the way through

GuitarLord5000 said...

I've tried the sour wort trick twice. The first ended up smelling like hot garbage and throw up. I boiled it, and the smell remained. I didn't even bother trying to ferment it. The second attempt was much better. I used saran wrap to cover the top of the wort to keep air out, and after 30 hours the wort smelled wonderfully sour, with only slight hints of hot garbage and throw up. I boiled and fermented it, and then dumped it. The resulting vomit smells were subtle, but still in the finished beer. And who wants to drink vomit flavored beer?! I've come to conclude that sour worting as a technique pretty much sucks.
How did your starter end up smelling by the time it was all said and done? I've been considering putting together a Louisiana Lambic culture using a similar approach. Leaving some wort out for the evening near some berry bushes, and then building up that culture to the point that it kills off the really unwanted critters.

Ryan said...

Guitar - Im kinda there with you on sour worting. However building up the starter as Ive done on this beer, and the funky peach seems to work wonders. I also did both during the cooler time of the year, which I think played into it as well. Being in Louisiana you might have similar results if you try it while its actually not scorching outside

My starter actually smelled extremely fruit and slightly acidic just before I pitched it. I had to add chalk a couple times to keep the acidity in check (Ive found wild cultures often kill themselves quickly)

GuitarLord5000 said...

I'd imagine it's hard to know what the fine line is between killing off the unwanted bacteria, and killing off the wild culture. Are you monitoring pH levels when you're doing the starter? At what point do you begin adding chalk? And how much chalk does the trick?

Eric said...

On a more general note. I have notice that you get extremely high efficiencies in your beers. I never get above 70% efficiency. Recently I bought Monster grain mill and mill much finer than I normally mill and then add 1/2 pound of rice hulls to prevent a stuck mash (the first time I did it without rice hulls and got a stuck mash so I am probably at the finest I can go) and I am getting closer to 75% efficiency, but NEVER 91% efficiency. Any tips you can pass along??

Ryan said...

Eric,

I think there are a couple areas that really help me get great efficiency

1 - good crush, not fine enough to cause a stuck mash, but as close to it as possible

2 - thick mash

3 - total sparge volume / total mash volume == big number

4 - after mash out I typically drain the bed almost entirely dry before turning on my sparge water

5 - using a pump to recirculate (A LOT) when vorlaufing. This really helps to make things uniform and get lots of the sugars early

6 - my system design. I have a buddy who used the same cooler, but a different manifold, and no sparge arm, he gets about 70% efficiency

Subscribe via email

Enter your email address:

Delivered by FeedBurner

Search This Blog

Followers

Related Posts with Thumbnails