Editor’s Notebook: Brewing with Sourdough Culture at Scratch

Scratch—the rural Illinois brewery just nominated for a James Beard Award—is known for a seasonal range of beers made from foraged ingredients. Less well known is what they use to ferment most of those beers: the same stuff they use to raise their breads.

Joe Stange Mar 14, 2020 - 8 min read

Editor’s Notebook: Brewing with Sourdough Culture at Scratch Primary Image

Photo courtesy Scratch Brewing

When I taste a flight at Scratch Brewing in Ava, Illinois, the first thing I notice is the sense of balance. They intrigue through the use of ingredients such as chanterelle mushrooms or toasted hickory bark… yet those flavors are more familiar than odd—fruit, spice, smoke—and in full harmony with the rest of the beer. Most of them are really drinkable—and tasty, too.

So, I am surprised—and then I feel guilty for being surprised. It means I was biased against them from the start. Why? Because of years of trying too many bad spiced beers, made from hasty ideas, things grown in gardens and fields, or found in the supermarket spice aisle—where a risk taken by a brewer’s foggy notion exceeds the tolerance of any drinker beyond a few sips.

The second thing I notice—and it interplays beautifully with the first—is the delicate texture and how nearly all the beers seem to lightly tingle away to dryness on the tongue. Some are gently tart, others more peppery-spicy, but they all finish in that light and dry way that recommends another sip (please) as soon as you don’t mind putting that glass back to your lips.

At this point, we must give some credit not only to the creatures who, through years of trial and error, have developed some thoughtful recipes—they would be Marika Josephson and Aaron Kleidon, the founder-brewers—but also to the creatures who actually make the beer—they would be the yeast.


It’s the same stuff that goes into their excellent, crusty bread loaves.

“Our house sourdough culture was created in our kitchen from nothing but flour, water, and what was floating around in the air,” Josephson says. “We created it to make sourdough hearth bread and pizza, not beer. But after we played around with it on a homebrew scale with good results, it didn’t take long for us to scale up and start using it in the brewery.”

Whenever Josephson and Kleidon decide that something works, it’s wise to pay attention. Besides their recent Beard nomination as outstanding wine, beer, or spirits professionals, they won a Great American Beer Festival medal in 2016 for their Oyster Weiss, brewed with oyster mushrooms and turmeric. They also published a book that year, The Homebrewer’s Almanac: A Seasonal Guide to Making Your Own Beer from Scratch. It’s packed with recipes built around things you might be able to find in the backwoods or backyard at any time of the year—from a wild-grapevine wee heavy to an arugula rye porter.

Here is one thing the book doesn’t mention: that sourdough culture. It wasn’t until after the book was published that they started to scale it up and brew with it more often. It took a while to get there.


“It was a long process of understanding the culture and how it worked—the flavor profiles it produced, how to make a beer sour or not sour, when it was healthy, and the quantity to pitch,” Josephson says. “We’re still learning about it after six years.”

One of the surprising things about the culture is its versatility. Technically, a sourdough starter is not only yeast—it’s also Lactobacillus, hence the mild, sourish taste of a good loaf. Hops inhibit its production of lactic acid, so a brewer can control the acidity to some degree. Want it more tart? Use less hops. Want a more saison-like profile? Use a bit more hops.

Josephson says there’s no reason why homebrewers couldn’t use a sourdough culture in their beers. She recommends a book called The Bread Builders, by Daniel Wing and Alan Scott, for learning how to create a sourdough culture and bake crusty loaves with it.

If It’s Good for the Bread, It’s Good for the Beer “The biggest challenge, I think, is in keeping your culture healthy and happy,” Josephson says. “If it doesn’t bake good bread, it won’t make good beer. That’s a good rule of thumb because most homebrewers won’t have lab equipment to help them see what their pitch rate is on a brew day—we don’t have that equipment here, either. But you need to be confident that the populations of Saccharomyces or Lactobacillus are big enough to do what you need them to do.


“We found through months of baking and brewing that if our bread was rising up well, getting a lot of loft in the oven and nice pockets in the crumb, we had a healthy culture, and it was fermenting our beer well, too,” she says. “If the bread was dense and flat and small—if it didn’t rise well—our beer was simultaneously going through poor fermentation. Using the bread as a judge is just a good indication of whether the yeast is happy and healthy. I’ve talked to a handful of commercial brewers who have used a sourdough culture and asked for advice, and I think everyone who had problems has said they had a lackluster culture that wasn’t making very good bread.”

Josephson says that they haven’t really tinkered much with the sourdough culture—they like it how it is. “We haven’t added anything to our culture,” she says. “It is just as it was to start. We feed it flour and water every week, and we feed it flour and water to build it up for a pitch into beer.

“That said, we have changed our actual flour in the past year. We use all locally grown and milled flour in our kitchen now. We were worried about how that may affect our beer. I think it still remains to be seen. But so far, the fermentation profile seems to be just as it was.”

However, a major reason that Scratch’s beers have attracted acclaim is that they are products of extensive trial and error. Just as Josephson and Kleidon experimented with many different ways to use various foraged ingredients over hundreds of homebrew-size batches, they are likely to continue exploring what else they can do with their yeast, too.

For example, Josephson says they have considered blending the sourdough with other cultures, “just to give us a different range of flavor profiles and to see what it would do. I think that’s a project we’ll be working on in the coming year.”

Any visitors who come to try the results—or any brewers who decide to try it on their own—would be wise to do so with their minds wide open.