Saturday 12 July 2014

2014 Wild Yeast Hunt

This years sources of wild yeast, waiting for wort.
L->R: Clover, Chokecherries, Raspberry, Tomato, Blueberry, Young hop (goldings)
I've been doing a bad job keeping my hunting wild yeast project up to date. The brief re-cap would be that I captured and characterized a series of wild yeast I purified off of some Pilsner malt. The first results were not satisfying, but I kept the ferment going and continued to collect yeast over a period of 6 months. To summarize the results of the over 80 strains I captured and tested - they all sucked. Only half attenuated worth a damn, and those which attenuated left beer that tasted either oxidized, phenolic to the point of being undrinkable (burnt plastics and dirty socks abounded), or both.

While the first hunt didn't turn out as well as I had hoped, it did serve to get a lot of groundwork established.  I now have a tried and tested method of identifying yeasts using DNA sequencing (posts 1, 2, 3 and 4), as well as my purification methods down pat...so its time for the 2014 hunt!

This years strategy is a little different. I'm stealing some wort from my Ephemeral Cranberry Wit, and am inoculating it using various yeast sources from around the yard. My wife runs one hell of a garden, and form there I'm taking yeast from some raspberries, blueberries, tomatoes, and strawberries. In addition, we've got some hops, choke-cherries and wild clover growing in the back, so I'm going to harvest from those as well. Each fruit/veg (OK, technically they're all fruits but the clover & hops - which are neither fruit nor veg) will be dropped into ~25ml of freshly brewed wort and allowed to ferment out for at least a month.

After the month is up I'll do my first harvest of yeast, plate them out, and see what I find.  Every month or so thereafter I'll repeat the harvest. Interesting yeast will be kept frozen and eventually subjected to fermentation tests to see how well they work, and how well they taste. I'm also going to harvest the end-product of the ferments (at about 6 months) as mixed cultures, potentially for use in some sour beers down the road.

I'll add more posts as we go, but to finish here's some semi-artsy shots of the yeast sources.
Clover

SWIMBO's garden

2 comments:

  1. This is a pretty damned cool project. I'm a little shocked that out of 80 harvested strains, none proved drinkable. I suppose I shouldn't be, but I have heard so many stories that seemingly work out the first time (that yeast isolate captured from some guys beard, and Dogfishhead harvesting wild yeast near date palms in Egypt come to mind) that it seems like something would have come of 80 trials. But, I suppose those are the interesting stories to tell, not all the times it doesn't work.

    Sweet garden btw- I am jealous, as we don't get nearly enough light in our yard, and I've never been ambitious enough to knock down a few trees to get some tomatoes.

    - Dennis, Life Fermented Blog

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    1. I was pretty mad when I went through all of that and ended up with bupkis. But in retrospect, the source was malt which would have been sanitized by the killining process, and then reinoculated by whatever it came into contact with later on. I'm hoping that by starting with fruits/etc that may be expected to naturally harbour more of the good yeast I'll have better luck.

      Most people who've done the wild-yeast thing successfully used fruits, or harvested near orchards/etc. I'm hoping that's where my solution lies.

      Bryan

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