Cultivating bottle dregs
UPDATE NOTE: This post describes a failed attempt at cultivating bottle dregs. If you’ve found this page looking for information on how to cultivate bottle dregs for pitching into beer wort, thank you for reading but please do not follow my process below. It didn’t work for me, as you can read in my follow-up here.
After deciding to brew a Bronze Age-inspired fig beer, I quickly went to work on the recipe in the hopes of brewing it on Monday (which I have off from my day job). It’ll be a 1-gallon experiment batch, with 2-row barley and rauch malt for that Bronze Age kiln-smoked flavor. Bitter orange peel will feature as a flavoring, and I haven’t decided yet whether it’ll have minimal hops or none. Honey and figs will round out the flavor and provide additional fermentable sugar. For yeast, I plan to cultivate a 2-step starter from the dregs in a bottle of Dogfish Head Midas Touch.
I’ve never cultivated a starter from bottle dregs before. Why now, and why Midas Touch? One usually hears about brewers cultivating dregs from sour beers like Orval to harvest the unique blend of Brett and bacteria strains that make those beers special, as described in this blog entry from TheMadFermentationist.com. But it should work with clean Saccharomyces as well.
I’m not sure what kind of yeast is used to ferment Midas Touch, though clone recipes online call for Trappist ale strains. I don’t even know if the yeast Dogfish Head bottles Midas Touch on is the same as the yeast that ferments it – many breweries use different yeasts for bottle conditioning. So my decision to use Midas Touch dregs was less about capturing a particular unique yeast than it was about superstition.
9 out of 10 prehistoric shamans agree: Consume your totem’s essence to gain its power.
Midas Touch is one of Dogfish Head’s “ancient ales” and is based on chemical analysis of bronze vessels found in Gordion in Central Turkey – roughly the same part of the world as Cyprus, where my fig beer has its inspirational roots. I thought the dregs might be a good luck charm for my first foray into ancient brewing: a little piece of the magic from Sam Calagione and Dr. Patrick McGovern, two of the high priests of modern ancient ale reproduction. But really, the main reason I did it was because it sounded like fun and I’ve never done it before.
I made a first-step starter wort of 200 milliliters to bring the bottle yeast back from the dead. When that ferments out, I’ll “step it up” to a second starter of 500 mL. For a full 5-gallon batch I’d continue stepping up to 2 liters, but for a 1-gallon batch, 500 mL should suffice.
I scaled down my usual starter process as well as I could, realizing it’s okay if some the math isn’t exact in a wild-shot experiment. I dissolved 15 grams of extra light dry malt extract in 200 mL of boiling water. Usually I use 1 gram per 10 milliliters, but I’m hoping the lower OG starter will give a little advantage to sleepy yeast.
I also added 3/32 of a teaspoon of yeast nutrient. While that sounds like a strange fraction to use, it’s simply one each of the “pinch” and “smidgen” measuring spoons (or 3 “smidgens”) available at specialty kitchen stores. Those little spoons aren’t all that useful on a day-to-day basis, but I keep them around just for tiny measurements like this. For the record, an exact scaling of my usual 1/2 teaspoon nutrient per liter of starter would have been 1/10 teaspoon.
It was almost too small to boil on the stovetop.
5 minutes of boiling reduced the starter volume more than expected, so after I cooled it and transferred to a sanitized pint glass, I topped off with pre-boiled water and chilled in the freezer to an acceptable pitching temperature of 84°F. I roused the yeast in the last half-inch of a bottle of Midas Touch (which I had already poured into a glass and was drinking) and pitched it.
Ready for the stir plate.
As of today, there’s no visible sign of fermentation in the starter, but there is a pleasant boozy smell coming from the glass. There’s no telling how few viable yeast cells were in that bottle, but even a few cells should reproduce given time.
We’ll see how it shakes out by Monday. I never do anything too crazy without a safety net, so I have a packet of Fermentis Safbrew T-58 – a spicy Belgian yeast strain with reported clove notes, which should go well with honey, fig and smoke – on hand just in case I don’t get a usable starter. But that’s Plan B.
Here’s hoping the Bronze Age beer gods smile on my undertaking.
The boldness of new beginnings
Foaming with abandon in the Harry Potter closet is a 2-liter Erlenmeyer flask on a stir plate, filled with a starter of White Labs WLP008 East Coast Ale Yeast.
She ain’t pretty, but she’s mah baby.
Anyone reading this who has been using liquid yeast without a starter should jump on the starter train. Seriously. It’s as easy as making a tiny unhopped extract brew, because that’s exactly what you’re doing. Just bring 1-2 liters of water to a boil – higher gravity worts will need bigger starters; see YeastCalc for the volume recommended for your batch – add dry malt extract at a rate of 100 grams per liter and some yeast nutrient if you’ve got it. This will make a wort of 1.035-1.040, which is perfect for a starter regardless of the OG of the batch it’s going in. Boil, cool and pitch the yeast. Ferment for 2 days, then cool in the fridge for at least 24 hours before making the “real” wort. Most of the yeast will drop out when chilled, leaving clear (but vile – don’t drink it) “beer” which should be decanted, leaving behind the yeast cake and just enough liquid to swirl up into a slurry. Pitch and watch the magic happen. If you’ve got good sanitation techniques, making a starter carries minimal risk. The rewards are higher pitching rates and better beer. And it’s so easy, there’s no reason not to.
This starter was pitched with yeast that expired in July. I’ve worked with expired yeast before. The yeast/bacteria blend in my Bacillusferatu Berliner Weisse was expired for ten months before I pitched it, though that was into a 1-gallon test batch of a low-gravity wort intended for souring. This starter is going into five gallons of wort for a very different beer: my long-overdue Colonial Progress Ale, from a recipe slightly modified from one I posted in April. Details forthcoming after I brew it this weekend.
As the photo above shows, the expired yeast is spewing so much krauesen I had to wrap it in a paper towel. The expired yeast are healthy as can be, and that’s no surprise. Sure, the expired vial had no more than about 10% of its original population of viable yeast cells, but so what? Yeast cells are dying every day in every carboy, keg and cask in the world, but fermentation continues. Many homebrewers culture yeast from commercial bottle dregs and make great beer with it. Given enough time, even a few sad, dying yeast cells will get their freak on, reproduce and ferment wort. It’s just that the first generations will be weak and languid, and make lots of foul-tasting byproducts doing it.
The purpose of the starter is to make sure those nasty byproducts end up in a beer that’s destined for the drain, not your gullet … while the real wort gets inoculated with a healthy colony of the naturally selected descendants of those few Saccharomycean pioneers who survived the long winter.
So don’t ever be afraid to use expired yeast. Don’t throw it away. You should be making a starter anyway. For fresh yeast, a starter is a leg up. For expired yeast, it’s a new beginning.
Speaking of new beginnings, best of luck to my friends and fellow writers undertaking National Novel Writing Month (“NaNoWriMo”) this November. The goal is to write 50,000 words of a novel in 30 days: fast, raw, unedited. I’ve done it four of the last five years and made it across the 50k mark each time. But I won’t be doing it officially this year. I’ve got too many short stories I want to work on, and a novel already in progress, and I don’t want to distract myself with something new. But I am using November as an excuse to write every day: a blog post, story, novel chapter, anything. I did catch wind of a blog-centric version (“NaBloPoMo”), but I love my readers far too much to subject you all to a bunch of hurried blog posts on whatever random bullshit I can think of to write about.
What do you mean, too late?
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