This has got to be one of the easiest ways of harvesting wild yeast, at least of the methods I’ve tried it worked on the first try and I’ll be brewing a beer to ferment with this yeast this coming weekend.
As you may know honey is naturally preservative, ie it won’t ever spoil on its own. Honey has some natural anti-bacterial properties in it, bees are pretty awesome that way. Of course one of the main reasons that honey won’t go bad is because sugar is a preservative. Yes, sugar. Ever noticed how the bag of sugar in your pantry also never goes bad? Sugar at very high concentrations is a preservative. Think of the fruit preserves your grandma used to make perhaps.
Anyway just because honey is a preservative doesn’t mean there’s not some of our friendly yeasty pals sleeping dormant in the honey just waiting for it to become diluted enough to get to work on all that glorious sugar. The key to harvesting yeast from honey is to get raw or unpasteurized honey. I was lucky enough to buy a whole bunch from a neighbor of mine that keeps hives in their back yard. So the yeast is a uber-local, yay!
Anyway, what you do is get a sanitized container, like an ehrlenmeyer flask or heck use a clear beer bottle. Add some of the unpasteurized honey, add about 4-5 times as much water as honey, plus a bit of yeast nutrient or energizer. Swirl it all up to dissolve the honey and nutrient in the water and then stick a bung and airlock on and wait. Don’t become discouraged it may take a few days, my concoction sat around doing what looked like nothing for a couple of days before I noticed the beginnings of fermentation.
I’ve only done this once and it worked, and was not contaminated so I’m not sure if that’s typical with harvesting yeast from raw honey or if I’m just lucky. However you will likely be able to tell by sight and smell if you have an infection. if it looks like you’ve just got yeast let it ferment completely and let the yeast settle. Then draw off some of the fermented liquid (which is technically mead) with a thief or baster and give it a taste. Mine had some fruity notes which I’m not sure if they were from the honey or the yeast (the local honey had a really fruity flavor to it) and no off tastes like bandaid or solvents.
If the yeast seems good then on to the next step: ferment a beer with it! which I’ll be doing hopefully this weekend. I put together a simple recipe for a sort of belgian pale ale and I’ll be adding my small starter of wild yeast to it and see what I get.