Capturing wild yeast from leaf litter

About a year or so ago I came across this video from Sui Generis about where wild Saccharomyces cerevisiae can be found:

I personally have a hard time believing the first part of the video about yeast being extremely rarely found on fruit simply due to the amount of successful yeast captures I have done from fruit. Though maybe many of these are not S. cerevisiae? Anyway, the part that interested me was finding wild S. cerevisiae on leaf litter on the ground. It makes sense since yeast can’t really fly, air can blow it around but it probably mostly just lands on the ground (vs on fruit hanging up in trees (defying my earlier assertion that fruit does indeed contain yeast)) and takes advantage of any available food or sugar it happens to come across, probably relying on other microbes to break larger carbohydrates down to the simpler sugars it is able to metabolize. I figured I’d give the idea a try.

I had been wanting to do a wild capture from an area of a nearby hiking trail where that had formerly been a brewery back in the 1880s. There’s some interesting history around this brewery. It was operated by a man named John Nagar in the town of Camas, WA. A year or two after he’d opened his brewery the town voted in their own city-wide version of prohibition (ahead of the nationwide constitutional amendment version). Nagar fought against this local law, even going so far as to put a whiskey scow out into the Columbia River with a bar on it to skirt the ordinance. Of course he was eventually defeated, and his brewery closed.

Fast forward to present day and there is a hiking trail along a creek that passes right by the former location of the brewery, there aren’t any obvious signs that any buildings used to be there but it has been over 100 years. I went down to the area where I’m guessing it was located based on an old map of the city and a spot along the trail where there is easy access to the creek and a spot that looks like it might possibly have been an old foundation, a bit of a somewhat rectangular looking cut into the side of a hill.

I gathered rotting leaf samples from four spots around this area and took them home. I prepared some 1.030 hopped wort for starters and since I was dealing with rotting leaves, I fortified the starters with vodka to bring them to ~2.5% abv and purged the headspace of the flasks with CO2 as well as I could just to protect against the plethora of undesirable microbes (mold, botulinum, etc) that are probably contributing to the leaf rot.

After about 5 days I began to see activity in the starters indicating some fermentation was probably taking place. One of the three grew what looked sorta like a glob of snot on the surface, maybe the beginnings of a kombucha type pellicle? The other three seemed normal, one had a bit of a ‘normal’ pellicle. After a couple of months I filtered all of the leaf particulates out and stepped up each of the captures. Three of the four took off, the one that grew the snot didn’t take off as much and I abandoned it at that point. The other three fermented out completely and dropped incredibly clear. They all tasted extremely similar (not too surprising), they were actually quite neutral, very mildly phenolic and minor ester production, but nothing compared to most of my other wild captures.

I split the three cultures among some saison wort for a real test. All three came out tasting pretty much the same (no big surprise), fairly clean, mild phenolic spice, not especially notable. Don’t get me wrong, they made good beer. Just the amount of yeast expression was muted. For a lot of brewing history including today this is a desirable trait. But of course I’m a weirdo and I like crazy yeast flavors. That said, these yeast certain could have a place in my repertoire for making hop or malt forward beers.

In the end, while the yeast itself isn’t especially exciting, the fact that it originated from some rotting leaves I picked up off the forest floor in the middle of December is pretty cool.

I harvested the leaf litter in December of 2017, I should have posted about this a lot sooner than now, but I’m lazy. Opening a bottle now, the beer is tasting like a nice biere de garde.

The appearance is light amber with a white head that lasts; clarity is pretty great (not unexpected after about 6 months in the bottle).

The aroma is malty, almost lagery?

Taste is malty with a hint of biscuit and caramel. Maybe a minor phenol in the background, but I might just be putting it there because I think it should be there…

Overall, this beer is pretty delicious, a nice malty beer, especially on a cold, nearly winter day like today.

One last thing to note on this post and then I’ll be done. I pitched this culture into a sort of Baltic Porter that I brewed last weekend and it is fermenting away just fine at 56F in my garage. Maybe it really is a descendant of a lager yeast from Nagar’s brewery?

A tale of two yeasts

or why it’s important to do multiple captures from one source

Last July I went cherry picking with my family in Hood River, OR. We picked a lot of cherries. Since some of the cherry picking help was from my 5 year old daughter, a few of the cherries we ended up with were slightly less than desirable for eating. I took it as an opportunity for an experiment. I cooked up some hopped starter wort and split it into two flasks. Then I took a few cherries that looked good enough for eating and added them to one starter and took a few cherries that had already begun to show signs of rot and added them to the other starter. Otherwise all of the cherries were from the same orchard so in theory you’d expect any microbes on the cherries to be the same/similar. I labeled the starters as 🙂 for the good looking cherries and 🙁 for the rotten ones.

Not unexpectedly, the 🙁 starter produced a krausen about a day sooner than the 🙂 starter did. The 🙁 starter also grew a bit of mold on one of the floating cherries before the krausen formed and completely overwhelmed it. I let them finish completely and then sit at room temp for a while before crashing, decanting and adding to new wort. Both starters smelled and tasted okay so I deemed them worthy of fermenting some real beer for consumption.

I brewed up a saison-like beer and split some wort between the two yeasts, I let them both ferment until I was fairly confident in the final gravity and then bottled them. Unfortunately something went sideways with the hops (I think oxidation from being lazy about revacuum sealing the bag of hops in the freezer?) and the bitterness on this beer was pretty harsh and somewhat overpowering. Regardless I still took some tasting notes but decided that I’d have to rebrew and try them both again before making a final judgement.

Here are my notes from the first tasting:

🙁 Culture

bubblegum/clove in the nose
slight clove and fruit in the taste with a harsh bitterness in the finish
more clove and some banana comes out as the beer warms

🙂 Culture

smells slightly of chlorine? or metallic?
kind of feety in the flavor
bitter finish, not quite a s harsh as 🙁
more foot aroma as it warms

So a pretty stark difference even in a batch with a pretty big flaw (that didn’t come from the yeast).

The second brew turned out well and I was able to taste the flavors of the yeast a bit better. I let this batch ferment for much longer (3-4 months) as I got busy with other stuff. Over this period the 🙂 batch formed a pretty funky pellicle while the 🙁 batch remained clear with a few persistent yeast rafts. This batch did not have a bitterness issue as I used a different bag of hops.

Here are my noses from tasting this second batch:

🙁 Culture

Aroma: Mild funk, cut hay?
Flavor: barnyard, mild spice, dry, malt hiding in the background and a soft smooth bitterness on the finish
Mouthfeel: well rounded from the carbonation
Clove and some stone fruit comes out as it warms

🙂 Culture

Aroma: sweet mousiness
Flavor: strong mousiness dominates throughout, some sort of phenol in the background? hard to tell with all the THP; slight tart fruitiness in the finish

So it seems the foot aroma went away and was replaced by a mouse. Even though THP flavors are supposed to fade with time, they can last up to a year, and the THP seems to have increased since bottle conditioning the beer so I’m not sure what’s up with that. After this batch I have decided to toss the 🙂 culture and only continue with the 🙁 culture.

It is amazing the stark differences between the two considering they both came from the same orchard. Also, one would expect to get weirder, funkier, nastier flavors out of the cherries that were already rotting but was not the case here. What conclusions can we really draw from this single point of data? Not much other than if you’re looking to catch a good wild culture from fruit, it’s a good idea to make a number of starters with your source material so that you have more chances to get a good culture.

Wasp Saison Tasting

Appearance: very pale straw and crystal clear with a big rocky head that is quite slow to dissolve.

Aroma: a bit of barnyard funk, slight malt/hops.

Taste: light beer flavor with an overtone of Brett funk throughout. For such a low abv beer there’s still a nice touch of maltiness and pretty strong funk considering. Hint of clove in the background.

Mouthfeel: fairly light, but not quite watery. Maybe a little watery.

Overall impression: As a super session saision, an attempt to make a hydrating beer for feeding to summer farm workers this definitely succeeds. This is actually my favorite variation of them. It seems like with so little malt sugar it’s difficult for sacc yeast to produce a lot of it’s signature flavors. Brett doesn’t seem to have that problem though it seems like bottle conditioning helped it out. I think I will make this beer again next spring in larger quantity if possible.

Dry hop run down

A member of my homebrew club brought a ton of hops to our Christmas party in January to give out and I went home with three good sized bags of hops. Two of which were Chinook, which I really dislike when used for bittering. I mentioned on twitter that I wasn’t sure what to do with all of these chinook hops, and another member of the club, Tyler, tweeted back that he was in the same boat.

I suggested we try them as dry hops:

An interesting idea that’s been floating around in the craft brewing and homebrewing arenas recently is getting yourself some generic american light lagers, opening the bottles and dry hopping them with a few pellets of hops. You use a variety of hops (though only one variety per bottle) let them steep at room temp for a few days, then chill, decant and taste. It’s a way to give yourself an idea of how that hop variety would taste when used as a dry hop without much in the background beer to muddy the waters (so to speak). I believe this idea originated with Anchor Brewing.

This idea resonated with tyler, and he suggested we do so with a large variety of hops and bring the resulting beers to the next club meeting since the theme was hoppy beers. He got some additional hop varieties donated from our LHBS, I had some additional pellets in bulk in my fridge, in all we ended up with 11 different hop varieties dry hopped in Coors Light since we couldn’t bring ourselves to buy Bud (lesser evil I guess? we were gonna get Miller Lite but couldn’t find it in bottles).

Anyway, after that long introduction here are my notes on the hops we sampled:

  • Hallertauer Hersbrucker – quite lemony, herbal
  • East Kent Goldings – mild herbal
  • Amarillo – fruity and delicious
  • Willamette – cheesy (these were also gifted at the club party and had apparently not been stored well, I doubt this is representative of the variety)
  • Horizon – herbal, slight lemon
  • Cascade – fruit, citrus
  • HBC 438 – slight peach and licorice? this one was kind of odd
  • Glacier – herbal
  • Mosaic – overwhelming cat piss, lemon, fruit
  • Falconer’s Flight – really lemony
  • Chinook – herbal, flowery; could be good dry hopped in a saison

A few things that stuck out to me:

I was surprised at the lemonyness of the Hallertauer Hersbrucker. That wasn’t something I would expect from a noble hop.

I didn’t hate EKG or Chinook as dry hops. I generally dislike both of these hops when used in the boil. I’m actually looking forward to using the Chinook as a dry hop in some saison down the line.

I thought Mosaic was disgusting, it was super cat pee. I’ve gotten this before from beers featuring Mosaic, but generally not as a dry hop. I used to think it was a 30 minute addition that brought out the cat pee for Mosaic, but now I’m wondering if there’s something else at work here (harvest time, hop yard, vintage?).

The Willamette were cheesy, I guess they hadn’t been stored well, but it’s still not a loss, I’m going to put them into a paper bag and let them sit out and fully oxidize, the cheesiness well go away and they’ll eventually be good hops for use in sour beers.

All in all it was a cool experiment and an easy one to do to try out a whole bunch of hop varieties. Just don’t be too upset about drinking some hop particles as they don’t always like to stay at the bottom of the bottles.

Raw brett ale tasting

Appearance: Fairly clear light straw color with minimal head that dissipates quickly into a thin surface lacing. Vastly different from the other raw beers.

Aroma: Slightly hoppy with a rustic barnyard note: earthy, herbal.

Taste: Grainy, herbal, a touch of citrus/lemon, funk throughout. I love it. The taste is everything I want out of a farmhouse ale.

Mouthfeel: Fairly thin but not watery; hard to explain.

Overall impression: This is a great beer; like I said above, it’s everything I want a farmhouse ale to be. I’m really pleased with this, especially since I was initially considering dumping it. This was the other half of the batch with the cypress/lemon balm wort, fermented with a wild sacc/brett mix for four months. It had this sort of unpleasant dirt flavor going on that I really disliked, I think from the lemon balm? I figured I should try dry hopping it so I filled a bottle from the fermenter, dropped a couple of horizon pellets in and a carb tab, after a week it was pretty good. I tried it again with some glacier pellets and it was also good so I kegged it with both and I was blown away! The dirt flavor is gone and replaced by this pleasant citrus note. Additionally the hops just seem to accentuate the funk from the brett. I need to dry hop with these hops more, they really are my favorite varietals.

Another thing rather striking is the clarity of the beer. Considering the other raw ales were quite hazy this one is downright transparent. I don’t know if that’s from the time or the brett or both.

Kveik Beer Tasting Notes

Appearance: The beer is a pale amberish to slightly red in color, with a respectable amount of head upon pouring that condenses into a mat of foam capping the beverage.

Aroma: A hint of roast (I assume from the victory malt) and subtle esters.

Taste: Malt and mild roast with maybe a bit of hoppy astringency. I think I don’t like the Sonnet Hops that I tried out for this beer. There are some subtle esters below the surface but nothing that really stands out.

Mouthfeel: Thin with high carbonation on the tongue. I may have bottled this too early.

Overall Impression: I don’t really like this beer all that much. Not that it isn’t a good beer, it is. There aren’t any off flavors that I can detect, I think it’s just the matter of I don’t like the Sonnet Hops. That said, I prefer the control I fermented with the same yeast (the one that came from my neighbor’s honey) that hadn’t been dried on a stick. The control seems to have more fruity esters and bubblegum flavor that I really like about this yeast. Now that I think about it, the kveikstokk yeast is a bit more similar to other wild yeasts I’ve captured from around the area here.

Raw Cypress Lemon Balm Tasting

Appearance: The beer is a pale amber and slightly hazy with a large pillowy head of foam that dissipates very slowly and never fully goes away. Quite a bit of lacing here as well.

Aroma: Grainy with a touch of an earthy herbal aroma and some fruitiness with a hint of lemon that comes out more as the beer warms up.

Taste: This is a malty beer with a fruitiness from the yeast and the herbs involved, it actually harmonizes quite well, nothing dominates. It’s not bitter but there is some hiding in the background, due to the beer’s dryness it, again, balances very well.

Mouthfeel: There is good body, it’s not thick like the spruce ale, but a nice body that sticks in your mouth for a bit after swallowing.

Overall Impression: This beer is very good, it’s extremely well balanced (toward the malty side). Considering that it’s a ‘herbal’ (not sure if cypress counts as a herb?) beer it’s not punching you in the face with either the cypress or the lemon balm and if you weren’t told they were in there you may have difficulty picking them out.

Raw Spruce Ale Tasting Notes

Appearance: The beer pours a hazy light amber with a ton of foamy white head. As the foam collapses it forms a dense foamy cap that does not dissipate, or at least it hung around until I finally drank it down with the final gulp. Lacing is abundant.

Aroma: Wheaty with a slight maltiness, but the dominant aroma is of the spruce tips, a hint of pine but mostly a sort of cool fruity citrus? I know that doesn’t make any sense, deal with it.

Taste: Spruce up front, not piney but more fruity with a hint of ascorbic acid that grudgingly gives way to malt/wheat on the finish with a very slight fusel alcohol burn probably from the hot ferment.

Mouthfeel: Very full bodied despite the FG of 1.003, probably due to the extra protein.

Overall impression: This is a good beer, but not great. I’m not sure if that’s particularly due to the fact that it is raw, I think it’s more due to fermenting it too hot than anything else. I also think it could use a little more hop presence which can probably be achieved with additional mash hops and/or some hops in the first wort/whirlpool.

I’ve read that raw ales do not last more than four to six weeks (though I’m not sure when you should start counting). It’s been nearly a month since brewing this beer and it’s only improved thus far. I’ll be sure to update this post if it declines (or if it doesn’t).