I read an interesting pair of blog articles today on generating sourdough starters. Debra Wink, writing at The Fresh Loaf
, describes some challenges
to getting a yeast culture going and a somewhat technical discussion of her solution
, which involves adding pineapple juice to speed up the process of building the yeast-and-lactobacillus culture that bakers use to make sourdough breads.
I love sourdough; my partner bakes regularly with a well-tended starter that we got from King Arthur Flour. We've also experimented with building our own starters in the past. Part of it is the flavor — I love tart flavors in general — and part of it is my seemingly never-ending wonder about the alchemy of fermentation and maintaining living cultures.
I sometimes think there may be some overlap between my interest in sourdough and my interest in beer and wine.
Alchemy is a word I love to throw around in conjunction with fermentation. With beer, there are typically two alchemical steps: the conversion of starch into sugar, where grainy cereal is turned into sweet, sticky wort by soaking malted grains in hot water; and the conversion of sugar into alcohol and carbon dioxide by yeast. Each of these techniques was developed over thousands of years of beer brewing, and trained brewers had the skill to perform these steps repeatedly and reliably with essentially none of our modern understandings of technology.
That last sentence doesn't begin to describe what a marvel it is.
When I brew, I use a large Igloo cooler to maintain my mash in the narrow temperature range required for proper starch-to-sugar conversion. I have a fast, accurate modern bi-metallic thermometer to ensure that I hit my target temperature. But the thermometer has only been around since the 17th century and wasn't used in brewing until the 18th century!
There are a lot of... different understandings of the mechanisms of wild fermentation: like where the yeast and lactic acid bacteria come from and how to get them into your starter. Part of me really appreciates that there is still some mystery. Another part of me wants to know what is going on in this invisible, microscopic world and that part absolutely loved the discussion of how yeast might be activated from dormancy in sourdough starters.
There are many spontaneously fermented wines. There's a tendency in the fine-wine world to equate "natural" fermentation (without the addition of cultured commercial yeasts) with better wines. Some winemakers I've talked to, however, scoff at the notion, believing that the ambient bacterial culture in a winery will overwhelm anything that's present on the grape skins, meaning that, in a sense, they feel that the "wild" fermentation in many wineries is actually a form of cultured fermentation.
And in the Belgian breweries around Brussels where sour lambic ales are produced, some of the breweries have special slatted roofs over their fermenters, so that the outside air can carry in the complex mix of microorganisms that are responsible for the distinctive dry-tart character of lambics. It's claimed that the airborne bacteria change by season and that a true expert could identify winter lambic or spring lambic.
It seems highly likely to me that there are plenty of people out there operating on models of yeast propogation that are, by scientific judgement, incorrect. Despite that, many of them are able to produce breads, beers, and wines that I find utterly compelling. As much as I love science and deep understanding, I'm happy to have a little room for some good old-fashioned alchemy in my life. While I'm not going to stop reading articles like Debra's — and will recommend them in a heartbeat to my baker friends — I'm also determined that I want to leave some room in my life for alchemy.