Save the yeast!

My night-before-brew-day (Brew Day Eve?) ritual consists of a) weighing and grinding the grain for the mash, b) preparing the yeast slurry, if necessary, and c) setting out the first stage equipment. I mentioned the yeast preparation briefly in last week’s recipe, Mortal Sin, and promised to divulge my secrets for re-using and re-culturing yeast.

If you brew, you know that the right yeast strain can make the difference between a good beer and a great one. There are, in fact, certain beers that cannot be brewed without the correct yeast. Anchor Steam depends on a very specific warm-tolerant lager yeast; Belgian Trappist beers would just not work without a traditional high-alcohol tolerant strain; in trying to clone Dieu Du Ciel’s Mortal Sin last week, we went to great pains to capture and reuse the yeast found in their bottles.

The other thing about “the right yeast” is that it can get expensive. Fresh liquid yeast costs anywhere from $5 to $8 in the home brew shop. But if you can save it, re-use it, you cut the cost down. Tomorrow I will be brewing a Munich Dunkel lager, using the same Southern German Lager yeast from White Labs that I used to brew my delicious Munich Hell, Vienna Lager, Bock and Rauchbock over the last few months. Yup, using the same yeast, for the fifth time. Here’s how I do it. Caution: some purists, some much more scientific types, will cringe, shudder and scream at the computer screen as they read this. I know, this shouldn’t work this easily. But it does, it has, and I have no qualms about sharing my dirty little secret.

Yeast in Sanitized Milk Bottle
Yeast in Sanitized Milk Bottle

It starts on the day I rack a beer from primary to secondary. If the beer to be racked was brewed with a yeast I know I am planning to reuse soonish (within the next couple months, generally), and if the initial fermentation has gone well, as far as I can tell, I sanitize a glass pint-sized milk bottle. After racking the beer into the carboy, I scoop out, with a sanitized measuring cup, a cup or so of the dregs. These dregs consist of malt proteins, hop debris, and hopefully a fair amount of yeast cells. These dregs are poured carefully into the pint bottle, a solid rubber stopper is affixed, and the sample goes into the fridge.

Close up of Yeast
Close up of Yeast

A day or two before I will be brewing with the saved yeast, I sanitize a glass quart-sized milk bottle. I boil a cup of water with two tablespoons of dry malt extract for about 5 minutes. This wort is cooled to 70 – 75°F, poured into the sanitized quart bottle, and the saved yeast dregs are poured carefully into the cool wort. A little swirling to mix, and a stopper with an airlock is put on the bottle. I let it work for 12 hours or so, and if brewing is still a ways off I might “feed” the yeast again with another 1/2 cup of water boiled with 1 tablespoon of DME, chilled of course. Voilà, on Brew Day I have a cup and a half or two cups of active yeast slurry, ready to pitch.

In the case of a commercial yeast captured from a bottle, this process takes place a little at a time over several days, with a gradual slow build-up of a quarter to a half-cup at a time.

So, my Southern German Lager yeast is just beginning to foam and bubble, two hours after pitching, and should be ready to pitch in my Munich Dunkel in about 13 hours. See you then!

To Clone: A Sin…?

The idea of cloning a beer dates back to the earliest days of home brewing. I mean, ever since it’s been possible to brew your own beer at home, we have done so at least in part to try to replicate something we tried and liked that someone else brewed. The late Dave Line, a British beer writer of the 1970’s, is the guy I credit with the most influential pioneering work on the subject, simply called “Brewing Beers Like Those You Buy” (1978 Argus Books). Line researched and developed recipes for over 100 different beers from around the world (primarily British, to be honest, but..) and fostered the idea that a home brewer could not only save money by making his or her own at home, but could also make it as well as, if not better than, the big breweries… Dangerous concept!

I began writing for Brew Your Own a few months after the magazine’s inception in 1995. The original editor, Craig Bystrinski, was a college classmate of mine, and I signed on to do the occasional feature article and a monthly column, eventually titled “The Replicator”. Each month I offered a recipe for reproducing a personal or a reader’s favorite beer. The column grew out of an early feature which we called “Clone Your Own”, replete with pictures of Dolly the Sheep… In 1998, Storey Books brought out Mark & Tess Szamatulski’s Clonebrews, and I was asked to do the follow-up, North American Clonebrews, which came out in 2000. I will devote a post some other time to the method I use for cloning a beer, but I wanted to get the history out of the way before launching into the recipe for the beer I brewed yesterday.

My good friend Rick (aka the Webmaster) and his wife Sarah went up to Montreal a few months back and while there hit a brewpub called “Dieu Du Ciel”, “God In Heaven” – a vaguely Belgian inspired place, with a nice variety of beers, cool atmosphere, etc… and they also bottle. Rick tasted and apparently fell in love with one of their beers, and brought a bottle back to me to see if I could help him brew it. The beer was called “Péché Mortel”, “Mortal Sin”, and it was/is delicious. A big Imperial Stout, about 9.5% abv, brewed with coffee. Rich, dark, dangerously smooth, a wow of a beer. So naturally I set out to devise a recipe. I brew all-grain, so my recipe is not extract-based. Rick is gently being nudged in that direction, but still brews mostly with extracts and some steeping grains. I had to work out an equivalent recipe for him. So what follows are two different versions of the same beer. Rick brewed his last week, I brewed mine yesterday, they’ll both be ready about the same time (in June or July?) and we look forward to tracking down a bottle of “the real thing” and opening ours and comparing.

Mortal Sin
5 gallons, all-grain


  • 12 lbs. Maris Otter 2-row pale malt
  • 1 lb. torrefied wheat
  • 1/2 lb. chocolate malt
  • 1/2 lb. roasted barley
  • 1 lb. dark crystal malt (120°L)
  • 1/2 lb. coarsely ground French roast coffee beans
  • 21.2 IBU’s Northern Brewer hop pellets (2 oz. @10.6% aa)
  • 12.5 IBU’s Galena hop pellets (1 oz. @12.5% aa)
  • 5.1 IBU’s Tettnang hop pellets (1 oz. @5.1% aa)
  • 3 cups Dieu Du Ciel yeast slurry (recultured)
  • 2/3 cup dry malt extract for priming
  • 3 tbsp. dark roast instant coffee

The night before brewing, crush grains. On brew day, heat 18 quarts water to 165°F, mash in grains and coffee, hold 90 minutes @153°F. Heat another 14 quarts to 170°F. Begin runoff, sparge, collecting approximately 26 – 28 quarts of sweet wort.

Bring to a boil and add the Northern Brewer hops. Boil 30 minutes, add the Galena hops. Boil another 25 minutes, add the Tettnang hops. After 5 more minutes (60 total), turn off heat.

Chill the wort to 80 – 85°F, take a hydrometer reading, pour with some splashing into your sanitized primary fermenter. Pitch the yeast slurry, seal up and ferment at 65 – 68°F for 2 weeks or until bubbling in the airlock slows down to once or twice a minute. Rack to secondary and prepare to be patient. Age at 50° – 55°F for 6 weeks or so (check to make sure your airlock doesn’t dry out at any point!). Bottle, priming with the DME and adding the instant coffee at the same time. Bottle condition for at least a month; longer is better.

OG: 1086 – 90
target TG: 1018 – 22
expected abv: 8.5 – 9%
IBU’s: 125 (not really – see note)

Note on hops: the hop utilization factors I use (see earlier post) are calibrated for worts with an OG around 1050. In higher gravity worts like this one, hop utilization diminshes by as much as 20%. This beer probably ends up with more like 100 IBU’s, but it’s a very complicated calculation and not really all that important!

Note on yeast: Hopefully, one of the keys to getting this one “right” is  the yeast. I saved the dregs from the bottle Rick gave me (it is a bottle-conditioned beer), and gradually over a couple weeks fed the yeast and built up a culture big enough to brew with. I brewed a 2-gallon amber ale just to further grow the yeast colony, then put it aside. I will post about yeast-saving and reculturing at a later date… Anyway, I built up enough of a slurry that I could divide it and give Rick some to use, and I also used it yesterday. If you want to brew this beer and can’t get the DDC yeast, you can probably get close enough results with any fruity Belgian ale yeast, or even an Irish yeast, in a pinch.

Extract-based version:
Instead of mashing the 12 lbs. of pale malt, start by steeping 1/2 lb. each malted wheat, cara-pils, chocolate malt and roasted barley, all crushed, and the crushed coffee beans, in 3 gallons of water. Use a mesh bag to hold the grains for easier removal later. Raise the heat gradually to 165 – 170°F, cover, turn off the heat and hold for 30 minutes. Remove the grains and coffee, turn the heat back on. Bring to a boil, and add either 10 lbs. amber dry malt extract or 12.5 lbs. amber malt extract syrup. This is a lot of extract for 3 gallons of water, so be careful to stir it in and not let it stick/burn on the bottom of the kettle. When it comes back to a boil, add the hops as in the all-grain recipe. After the hop and boiling schedule, chill and add to your sanitized primary fermenter along with enough chilled pre-boiled water to make a little over 5 gallons. Mix gently and take a hydrometer reading. At 80 – 85°F, pitch the yeast, seal, ferment and condition as above.