Yes it is possible to dry yeast at home. No it’s probably not going to be completely sanitary, but if you read this blog at all, you know that’s not a super high priority around here. Anyway, how is this accomplished? It’s actually quite simple. Many of the traditional Norwegian farmhouse brewers have dried their yeast for ages, the method I’m about to outline I gleaned from them with the help of Lars Garshol’s excellent blog.
What you’ll need:
A baking sheet (not strictly necessary)
a couple of clothes pins or chip clips
A large spoon with smallish holes in it, a wire strainer would also probably work
Actively fermenting beer (preferably with a top-cropping yeast culture)
An electric fan
How to do it:
Start by clipping some parchment paper to your baking sheet
Next open your ferment at high krausen and scoop krausen out onto the parchment paper using a sanitized spoon.
Use the spoon to spread the krausen out into a thin layer so that it will be able to dry quickly. Place the pan in front of your fan blowing air across it on a low setting to help it dry faster.
After a day it should be fully dry and ready to collect. Crinkle up the parchment paper to get they dried yeast to flake off.
Dump the yeast into a clean dry jar. Label and date the jar and store it in the fridge or somewhere cool and out of sunlight.
Pretty simple and easy. My main barrier to doing this all the time is that fact that I generally ferment in glass carboys so I can’t get in there to scoop krausen. I have dried bottom cropped yeast slurry before and it does work, just make sure you are spreading it THIN, if it takes too long to dry you’ll end up with mold growing on it and nobody wants that. Like I said this is obviously not aseptically sanitary, certainly random wild yeast or bacteria in the air could land on your drying yeast and infect it. The drying process should help though as not all microbes handle drying all that well. If you do this to a wild culture you can certainly alter it, especially if you’re harvesting krausen, doing this over and over through a few generations you’ll definitely select in favor of the microbes that get going quickly and reduce the amount (or possibly eliminate) the slower acting microbes. Obviously this doesn’t apply when harvesting slurry post fermentation. With top and bottom cropping you’ll still be eliminating any microbes that can’t handle drying. This may eliminate brettanomyces from a culture as I have heard that yeast sellers have had difficulty drying brett to sell.
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?
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:
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
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:
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
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.
Recently I and some members of my homebrew club brewed 70 gallons of Belgian Dubbel in order to fill a former Merlot barrel. 70 gallons is quite a lot of beer and this brew required a large amount of belgian candi sugar. Seeing as how the stuff costs something like $7/pound at homebrew shops and it is basically just cooked sugar I went in search of how to make this stuff at home.
What I found was that “basically just cooked sugar” isn’t quite accurate. Despite what many online tutorials for making candy sugar tell you, there is a bit more to making candi sugar than cooking sugar syrup until it achieves a desired color. I found the process at the Sui Generis blog. The process is split among two blog posts and you have to do a bit of flipping between the two to determine the recipe which is kind of annoying so I figured I’d outline it here in a more readable way. I’m also making the syrup in a slow cooker which is a different and (I feel) superior method because you don’t have to be constantly monitoring it, stirring super hot boiling sugar, and stressing that it’s getting darker than you wanted. Another note: I’m outlining a 1kg sugar recipe here but accompanying photos are from a 3kg batch so bear that in mind when looking at the photos.
The basic premise behind this method vs just cooking invert syrup until it turns dark is that this method utilizes maillard reactions where the other method is only caramelization. With maillard you can get more complex and desirable flavors like stone fruit, raisin, etc. The main difference between this method and the cooked sugar method is that we’re not using any acid to invert the sugar (acid puts an end to maillard reactions) and are adding a base part way through to really drive the maillard reactions. I’m also making it in a slow cooker over the course of 8-10 hours depending on how dark you want it to get.
1kg table sugar
5ml dry malt extract (we need some nitrogen to help drive maillard reactions a tsp is fine)
Add your sugar, malt extract and 200ml water to your slow cooker, stir to make sure all of the sugar is wet. Turn the slow cooker on to high setting, put the lid on. If you’re able to weight the lid to help prevent any build up of steam from escaping do so.
Combine the slaked lime with the 60ml water in a glass and stir it up and then set it aside to allow it to settle.
Go away for an hour or so
Return and stir the sugar sludge in the crock pot it probably won’t be fully dissolved quite yet. Put the lid back on and leave for another hour or so.
Return to see that the sugar has fully dissolved. At this point our simple heating should have produced some inversion of the table sugar, enough to help with the maillard reactions we’re about to help initiate.
Decant the clear liquid that has separated from the lime in the glass, I use a sort of flat ladle spoon to do this. Also be careful as this liquid is incredibly basic and will burn your skin.
Add the decanted liquid to your slow cooker to increase the pH
Stir your sugar syrup up and replace the lid and weight
Go away for a few hours
When you come back the room will smell like baking cookies, check on the color, and see where it is at.
When the color/flavor is to your liking turn off the slow cooker and pour the syrup out of the pot and into something else to hold it for storage, mason jars or a disposable foil tray work well. Keep in mind that when this syrup cools it is going to be incredibly viscous and difficult to pour out of containers without warming it up quite a bit. With the slow cooker we aren’t bringing the sugar syrup to crack temp with this method so it will not completely solidify to the point where you can break it into chunks.
This is not all that difficult to do, probably the hardest part is acquiring the pickling lime as it’s no longer recommended for use in pickling. I ordered mine from Amazon.
Making your own wild fermented hot sauce or salsa is fairly simple. I use a few special things to make it a bit easier but they’re not strictly necessary. You can easily make this with equipment you likely have around the house. If you’ve fermented your own sauerkraut before then this process will look very familiar to you.
Basically choose what you think you’d like to have in your salsa/sauce. Understand that the lacto fermentation will add some sourness and possibly some fruity flavors to the final product. It will also reduce some of the heat of your peppers. The simplest recipe would just contain hot peppers and salt.
For my most recent creation I wanted to try incorporating pineapple into the ferment, hoping to retain a bit of it’s sweetness in the final product. I used:
1 12oz can of chopped pineapple
a few cloves of garlic
half of a sweet onion
I diced every thing up and added them to a self-burping fermentation jar. I weighed the jar first so that I could get a measurement of the weight of the ingredients after they’d been added to the jar. After weighing the ingredients (minus the salt) I added 2.5% of the ingredient weight in salt, sealed the jar and shook it up to distribute the salt and mix the ingredients. If you don’t have a scale to weigh out the ingredients you can just sorta guess with the salt, for a full quart jar of veggies to be fermented, use 1 tablespoon of salt. After shaking it all up I used a spatula to push any ingredients stuck to the sides of the jar back down and pressed everything down a little bit to make sure it was submerged slightly under a bit of brine that was being extracted out of the peppers, onion and pineapple (not to mention the syrup that came with the pineapple). Don’t worry too much about getting it submerged but you don’t want big chunks sticking out as they could grow mold.
I sealed the jar and left it in my office. Within a few days I could see that it was fermenting and had formed a bit of a pellicle on the surface. I let it go for a couple of weeks, the pellicle formed a few bubbles but there was no vigorous activity. This is what I was hoping for. I was slightly concerned that with the extra sugar from the pineapple that some yeast might take hold and ferment all of the sugar out completely. A vigorous ferment would indicate that this had happened. Lacto is generally a pretty low key fermentor, but it does generally form a thin pellicle so you can see that something is happening. Another nice thing about lacto is that it’s fairly lazy and it generally will not ferment all of the sugar available to it, or at least it will take its sweet time in doing so.
I left the jar to ferment for a few weeks. I mostly ignored it but every now and then the jar would burp itself and I’d get a whiff of fruity jalapeno heat as I was working. After I’d let it sit around for long enough (how long you let it go is really up to your discretion, some people only lactoferment veggies for a few days, some go for months) I took a taste and it was spicy with an underlying sweetness. I emptied the jar into a blender and ran it until everything was pretty well liquified. This turned it into a salsa of sorts, but without the chunks. If you want a hot sauce a la tobasco instead of blending you’ll want to press all of the liquid out and separate it from the solids. You could achieve this by wrapping it in a tea towel and squeezing it or hanging it somewhere to slowly drip into a container. I prefer to just blend mine, it’s easy and it tastes good.
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.
I realize I should have posted sooner about the wasp yeast. Here’s a picture:
WTF? yeah, I went and did that. It wasn’t completely my fault though. Maybe partially my fault. Okay, story time:
Ever since I captured some wild yeast from unpasteurized honey, I’ve had this thought in the back of my brain to somehow catch a bee and just throw the bee into a starter and see what I get. Well years have gone by and I haven’t done that. Then, one day a few months ago, I read an article that was posted on Milk the Funk about how some scientists determined that wild saccharomyces yeast will overwinter in the stomachs of queen wasps and hybridize in her gut. That’s kinda neat, kinda creepy too I guess.
A few hours after reading this information I was out putting some chicken into my smoker for the first time since last fall. I take the cover off, and what do I see curled up in the recess of the smoker door handle? It’s a wasp. I poked it with my finger to see if it was dead, it moved a bit, not dead, but pretty sleepy probably since it’s still somewhat cold. It’s an overwintering queen. I put her into a jar.
Coincidentally, I just happened to have to make some starters that same day for a brew day coming up. I took it as a sign from God; the wasp went into a starter. Of course by the time I was ready to put her into the starter, I had brought the jar into the house and she had warmed up and woken up and probably wasn’t too pleased about her imprisonment. Okay, so how do you get an angry wasp in a jar into an erlenmeyer flask full of wort? I thought I could put her in the freezer, but that’d take a while. In the end I just shook the heck out of the jar until she seemed to be pretty stunned then I used the flamed end of an xacto blade handle to crush her a bit and into the starter she went.
She was pretty slow to ferment initially, this picture is actually from before the starter krausened, so something else was going on in there. lacto? enteric? when I tasted the starter (before pitching it into my Farm Hand’s Ale) I didn’t detect any off flavors, mostly it was pretty bitter from hopping the starter, and had the characteristic fruity bubblegum flavors that other local captures of yeast around my neighborhood have. We’ll see how it goes. I made a lot of that beer so I can afford to let her portion age for a while to see what (if anything) shows up.
So, as you can probably guess, I love Saisons. The typical story told about the style is that it emerged from farmhouse brewing traditions in France where they needed a beer for their seasonal farm workers to keep hydrated while working. If you know anything about saison today you’ll know that it’s not exactly something that you’d want to drink a lot of and then go try to wield a scythe and get some work done. So it’s likely that the first saisons were much lower strength beers than what is typically available today. The BJCP has mentioned “Table Saison” as a variant of their 2015 definition for the style that ranges 3.5%-5% I actually wanted to make something that was even lower alcohol than that (if possible, I have this curse about trying to make session beers and they end up being 6-7% somehow). My goal was to make a beer that was around 2.5% abv, but hopefully didn’t taste too watered down.
Farm Hand’s Ale (15 gallon batch, 30 minute boil)
10lbs Northwest Pale Ale Malt
2lbs Flaked Oats
1.5lbs Aromatic Malt
1.5lbs Munich Malt
2.5oz Glacier Hops 3.2%AA FWH @30 minutes
2oz Glacier Hops 3.2%AA @2 minutes
I decided to go with the high % (though maybe not a terribly high amount) of aromatic malt for this to help give it a good malty flavor despite the small amount of malt being used. I included the oats to boost the mouthfeel of what is likely to be a rather thin beer otherwise. I used glacier hops because glacier hops are the best, and did a 30 minute boil because I like to shorten my brew day.
I mashed this beer rather thin since my HLT is my old 10 gallon boil kettle and I wanted to get 15 gallons of runnings so I mashed in with 9 gallons of water to achieve a mash temp of 155F and then sparged with another 9 gallons of water after about an hour. It took a while to get to a boil and my 19 gallon kettle was pretty much maxed out, I actually saved a few gallons off and added them to the kettle as I went to chill. Otherwise the boil went fine with no major hiccups.
I split the wort among 4 fermentors, 2 2.5 gallon and 2 5 gallon batches were all pitched with different yeasts. The 2.5 gallon batches got my wasp yeast for it’s inaugural batch and the other 2.5 gallon got some of my local yeast, that was harvested from a plum blossom. I think I need to just come up with a name for all of the local yeast captures, since they are all pretty much the same yeast. The 5 gallon batches got my hefe/brett (probably needs a better name) culture and my abbey culture that had been revived from a jar of yeast that has been in my fridge now for 3 years and 4 months, ha!
The original gravity came out to 1.031, which is 6 points higher than I was shooting for meaning my efficiency was 88.5% which seems incredibly high to me, I wonder if the thinner mash had something to do with that? So I guess this could possibly qualify at the low end a Table Saison depending on attenuation. All of the batches took off fermenting pretty quickly. I will post tasting notes when they are ready.
On March 5th I gave a presentation at the PNWHC about how to catch wild yeast. It went pretty well and I got a friend from my homebrew club to film it for me. So now it’s up on youtube for your viewing pleasure:
I’m also going to write out some words here describing what I talked about in the video for you people who hate watching videos like I do.
What is Wild Yeast
A lot of beers are marketed as wild if they contain brett, brett itself is often called a wild yeast, and WPL644 trois was thought to be brett but is apparently sacc and is being called a ‘wild’ saccharomyces. But if you buy a pure strain of brett from a lab, is it really wild? You know what you’re buying, you know basically how it will behave and what it will do to your beer. Maybe that yeast strain was wild once but I don’t really think that’s wild anymore.
My definition: Wild yeast is yeast that came from the wild
Sources of Wild Yeast
My favorite source of wild yeast is from fruit. As we all know yeast likes sugar and fruit generally is sugary so fruit would be a logical place to expect to find yeast in larger proportions. Some fruits I’ve gotten yeast off of: dates, juniper berries, cherries, grapes, apples. Other good options to try: raspberries, blackberries, blueberries, plums. Farm pressed unpasteurized apple juice is another good source, just get the juice, stick an airlock on it and let it ferment.
If you’re trying to capture a sort of terroir for a specific area then I recommend using fruits harvested from that area, either grown yourself or wild foraged. You can also get yeast off of store bought fruit, just try to get organic if you can and do not use irradiated fruit as that won’t work.
Veggies are another good source, though you’re more likely to find bacteria on vegetables. Think about sauerkraut, you chop up a cabbage, mix in some salt and it ferments itself; plenty of lacto there. Ginger root and it’s cousins (turmeric, galangal) seem to have a plethora of useful microbes hanging out on them including sacc, brett, lacto, even some useful molds.
Flowers are another option for wild yeast, especially if it’s spring and there’s not any local fruit in season to harvest from. I recommend using edible flowers, like apple/plum/cherry/peach blossoms, roses are also edible.
Raw/unpasteurized honey is another good source of wild yeast. Isn’t honey anti-microbial? It kind of is, but the main reason it never goes bad is that same reason that a sack of sugar in your cupboard never goes bad, the high concentration of sugar is the main thing that protects it. the sugar sucks the moisture out of any microbes that happen to be in there, causing them to go dormant or die. But the ones that don’t die are dormant just waiting for the conditions to become favorable, ie the sugar gets watered down.
Insects are another source of wild yeast. I recently read about how Saccharomyces overwinters in the stomach of queen wasps, a few hours later I just happened to find one taking a nap on my smoker, I also had to make starters for a brew that evening so I took it as a sign from God. She went into a starter as well, fermented quite vigorously too. I haven’t used her in a beer yet.
Open air inoculation is probably a method you’ve heard of for producing wild yeast beers. Lambic and other belgian sour beer producers utilize this method most famously and some american breweries have also begun replicating this process. I haven’t done a ton of open air inoculations, from what I’ve read of other people doing it, it’s a good way to catch mold, though I have been successful the one time I’ve tried it.
How to capture
So you’ve got your source, how do you get the yeast that may be on it into a beer? Essentially it boils down to: make a starter, add your source. However there’s a few things to do a bit differently for this starter:
if you’re just trying to capture yeast and not bacteria (yeast in this case includes sacc and brett) you should make a hopped starter, just toss a small amount of pellets in your starter before you boil it, you don’t have to target a specific IBU level hops will inhibit lacto even when dry hopped. Make sure your starter is high enough gravity (~1.030) to end up being above 2% abv when fully fermented out, this will kill enteric bacteria. I also add some nutrient to the starters to give the yeast some extra food. Shake up or otherwise oxygenate the starter before adding your source.
Add the source. If you’re inoculating from open air, I’d pour the starter into a sanitized shallow bowl, cover with cheesecloth to keep bugs out (or don’t) and let it sit out for at least 3-4 hours and not longer than 24 hours, shorter is probably better to minimize oxygen exposure and reduce the chances of catching mold. Then add it back to your starter flask. Put an airlock on the starter and don’t stir or otherwise try to aerate this starter at this point. This is to deter mold and acetic bacteria.
Wait patiently. I’ve had to wait upwards of a week before I noticed any visible activity/fermentation in some starters.
If you want to catch both yeast and bacteria then there are a few things to do differently. Mainly, don’t hop the starter. Add your source and cap the starter with foil and feel free to aerate. Try to keep the starter cool, in the low 60sF if you can, this helps the yeast to have a chance to grow alongside the faster growing bacteria which prefer warmer temps. Again, wait patiently.
Some nasty things can potentially grow in this first starter that can make you ill. You’ve probably heard that no human pathogens can grow in beer and this is generally true, but they can grow in wort. The reason why this isn’t an issue for homebrewers is that they are typically pitching a vast amount of yeast into their wort and nothing else is going to have a chance. With this first starter, we’re not pitching a vast amount of yeast, we’re pitching a tiny amount of yeast, and also a tiny amount of other microbes that we may not want.
Here are some things to do to lower the risk of those things taking hold.
Pre-lower the pH of the starter wort to 4.5 or less to inhibit E. coli and C. botulinum. Typical wort pH is 5.0 so you don’t have too far to go to get to 4.5. You can also fortify the wort to 4+% abv by adding a neutral spirit such as vodka, this will inhibit E. coli and outright kill enteric bacteria. You can also keep the starter for a month at room temp (not in the fridge) which will let E. coli really die off. You can read more about safety precautions here. I haven’t done any of these things (partly because I wasn’t aware of them until recently) and I haven’t gotten sick, maybe I’m just lucky? Regardless, if you do happen to be immune compromised then I recommend that you stick with lab yeast.
Did you catch anything good?
So now you’ve got your source in your starter, how do you know if you caught anything good? Well first off, did it ferment? Like I said earlier, be patient, you may have to wait some time to see any signs of fermentation and it’s also possible (but unlikely in my experience) that it may not ever ferment. If it doesn’t ferment then, obviously you didn’t catch anything you’d likely want to put into a beer. If it does ferment, let it ferment out completely.
Did it grow mold? If so you should toss it and start over. Yes there are some molds that aren’t harmful, but I don’t know how to distinguish them from the bad ones so better/safer to just start over.
If it fermented, how does it smell? If it smells awful, like poo or vomit or feet, you probably don’t want that in your beer so chuck it and start over. If it smells good, that’s a good sign that you got something good. If it smells good and didn’t grow mold crash it in the fridge, decant the pseudo beer from the top of the yeast and give that a (small at first) taste. It’s not going to taste exactly like beer but it’ll give you an idea. If it tastes good then you probably got something good.
You probably noticed I said toss it and start over a number of times above, while my success rate for catching wild yeast is above 50% there are many roads to failure at this step so you may want to make up multiple starters at one time to increase your chances of success.
Step it up
Now that you’ve caught something good it’s time to step it up to eventually pitch into a large batch. You can do a starter now how you normally would, though if you’re going for just yeast it won’t hurt to continue using a few hop pellets in your starters. Feel free to aerate your starter like your normally would at this point.
For newly caught yeasts I typically have a standard saison recipe that I like to pitch it into, but you can let your culture choose the style of beer you brew, if it seems very fruity, maybe a british or american style would be more appropriate. Spicy/bretty would lend itself to a saison or farmhouse beer. bubblegum and clove flavors could do well in a wit or abbey style beer. Did you go for bacteria and get some sourness? Brew a Berliner Weisse or Gose. Whatever you choose to brew for this initial large batch of beer, I’d steer away from overly hoppy or malty styles just so that you can really get a good understanding of the sort of flavors your yeast produces.
Keep in mind that your wild yeast may take longer to ferment a beer. I typically give my beers at least two weeks in primary sometimes as long as a month depending how busy/lazy I am. For the first trial of a new yeast, when it seems to be done fermenting ie the beer has reached expected FG (or lower) and doesn’t seem to be dropping any further, I like to rack a gallon into a separate jug, put it under airlock and stash that away for 6+ months just to see if the yeast does anything further with the beer. Sometimes after tasting that aged beer I’ve wished that I had left the entire batch to age. The rest of the beer I’ll keg, I recommend against bottling, especially for this first batch just because you don’t know if they yeast will slowly continue to produce CO2 and result in bottle bombs. If you are unable to keg then you could bottle and store the bottles in the fridge after they have primed, but I still caution against that as I’ve had some jars of slurry carbonate in the fridge. Cold temps aren’t a guarantee of stopping some wild yeasts, they can be very hardy.
Save the slurry
After racking the beer off the trub, I just dump it all into a jar and stick it in the fridge. Put a label on the jar or you will forget what it is. I have 2 mystery jars in my fridge right now. When I want to make a beer with that yeast again, I’ll make up a starter and just take a scoop of the trub from the jar and grow it up in the starter. In this way I always have a sort of baseline from which to draw, every beer with that yeast is ‘second’ generation. How long can you store it? I’ve had one jar in the fridge for three years and still got viable yeast out of it, though it took a lot longer for the starter to get going. Maybe it’s just that particular yeast, but like I said wild yeast is typically hardier than their coddled lab cousins.
Where to go from here?
Well obviously, make amazing beer. If you want to get more scientific you can learn about making plates for isolating specific yeast strains from your culture and making slants for better long term storage. I haven’t done either of these things yet. As we know with homebrewing, the rabbit hole goes ever deeper and you can go as deep as you want.
Here are some more great resources for info about wild yeast beer, sour and funky and other crazy beer experiments.
You’re probably already familiar with The Mad Fermentationist. If not it’s a great blog about wild and mixed microbe beer making (among other things). he has also written a book called American Sour Beers that I can’t recommend highly enough.
There is a facebook group called Milk the Funk that is just amazing. It’s full of tons of smart people who are happy to share their knowledge and are doing a ton or really interesting things with beer. Joining that group has vastly improved my facebook feed. Milk the Funk also has a website with a great wiki full of tons of great info.
The Yeast book by Chris White and Jamil Zainasheff is also a great resource though it can get pretty technical at times. It is packed full of great info about yeast in general.
Another great resource is Wild Brews by Jeff Sparrow, this book deals more with the production of Lambic and sour Flemish ales. There’s a ton of great info about a lot of the microbes we’re looking to catch though: Saccharomyces, Brettanomyces, Lactobacillus, and Pediococcus.
I hope this info is helpful to you. If you have any questions hit me up on twitter. Go catch some yeast!
Update: A Spanish homebrewing blogger requested to translate this post into spanish for his readers: here’s the post!
Update: A French homebrew blogger has translated this post into French.
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.