June 21, 2015

Spontaneous Fermentation Project Part 16 -- Eighteen Months

I decided this month I'd give this beer a taste and make a definitive decision on what to do with this beer. It's been long enough that if I'm not seeing something worthwhile develop then that is unlikely to change and I should use the carboy space for something else. This sampling was not encouraging so I decided letting whatever I captured on that bitterly cold night just isn't getting it done and it's time to admit failure. However, rather than dump the beer I decided to send in reinforcements and see where they can take the beer. Ultimately I may end up dumping this beer but for the cost of a few pounds of grain and some propane I had fun with it and learned something new so even if this beer ends up flavoring my backyard it wasn't a complete failure.

The sample I drew this month was a natural progression of where the beer was last time I tasted it a few months ago. The ph is still around the mid-4 range and gravity is still right at 1.010. By those metrics and the traditional lambic grist, this is just a generic wheat beer with a weird flavor. The flavor is what made me decide to pull the trigger. It was about as close to pure apple juice flavor as one can get. It tasted exactly like generic apple juice with a little malt mixed in. It was sweet, bland and apple-y. If you have ever had one of those Woodchuck graffs it's similar to that but if you cut it with unfermented apple juice so it had less malt flavor. Just not something I want or need in any volume. Visually the beer is reasonably clear with a slight haze, similar to an unfiltered wheat beer. The islands of yeast are still there, always mocking me.

I suppose it's worth diagnosing where things went wrong with this beer. My mistake was going forward with a brew day on such a cold day. By the time the boil ended it was about 8pm and the temperature had dropped into the twenties with an aggressive wind. The combination of those two things might not have been a problem except five gallons of wort is too little volume to cool at a reasonable rate under those conditions, especially when I broke it up among several vessels. The wort was freezing at the surface in less than an hour which meant I was getting very little contact time for microorganisms to descend into the beer and what was getting there was either dying by freezing or not having an opportunity to start building colonies right away. These conditions resulted in little opportunity for a wide range and sufficient numbers of microorganisms necessary to make good beer. That would explain why I ended up with little to no lactic acid bacteria or oxidative yeast needed to create a wonderful sour beer. The absence of pellicle in turn meant no regulation of oxygen contact and the apple juice flavor is likely due to oxygen exposure.

Rather than dump the beer and start over I decided to culture some reinforcements and see what happens. I whipped up six ounces of 1.030 wort and dipped a store-bought nectarine in the wort. It destroys the localness of the beer but I am more interested in gaining a good mixture of microorganisms than terrior. I let the wort sit overnight in a mason jar and then sent the open jar outside for several hours in the morning. There was clearly activity by the smell and after a couple days the aroma of lactic acid was assertive. Several days later a thin ring on the inside of the jar at the surface suggested a krausen had come and gone and left a thin layer of creamy white yeast at the bottom of the jar. After seven days the jar's contents registered at 3.6 ph. I added another six ounces and let the jar sit for two more days. Another krausen ring appeared at the ph clocked in just below 3.6 ph. Today I unloaded the contents of the mason jar into the spontaneous beer.

I have hope the reinforcements will get in this beer and make something work. The bacteria are apparently aggressive so sourness will hopefully develop. I'd like something more than sour apple juice so I am also looking for some activity from brett and its friends to throw up a pellicle and go to work on the available flavor compounds. If I don't see a pellicle within the next few months then I will consider pitching some brett to help the beer along. Hopefully I won't have to mess with this beer anymore and I'll be able to bottle something decent next summer.


Post a Comment