Thursday, January 9, 2014

Bread from Beer: Of Barms and Such

Much of what I have posted about bread here concerns sourdough, the oldest method of leavening bread, which is not only experiencing renewed popularity but never lost its centrality in much continental European bakery.

There is another ancient method of raising a dough however, which is of course yeast. But yeast in the modern sense, an independent (and, frankly, strange) product or substance added to doughs, is quite recent. The older means of harvesting yeast links bread with beer.

Britain seems to have been a cradle of this process, which is unsurprising because beers played a more central part in diet and sociability there than wine. At some point it was discovered that the yeast present in vats or on the froth on the top of brewing beer - barm - could be combined with dough to leaven it. The brewer and baker thus began a long and happy symbiosis.

I had wondered for some time about how to join in this tradition in my own kitchen. Specifically I wondered whether it might be possible to harvest the yeast from particular beers and perhaps import some hint of their character into bread.

There is not much out there to assist the optimistic baker with this task. One widely distributed recipe from Dan Lepard's well-known book The Handmade Loaf involves a "barm bread" which turns out really to be beer-flavoured, not beer-raised - a bottle of beer is added after being heated such that the yeasts would die (I think) and then more packaged yeast is added. This recent post is more authentic, but relied on supply of barm from a home brewer, not self-started.

The hint that what I wanted was possible came from looking at home-brewing sites, where bloggers and forum participants were discussing harvesting of beer yeast not for bread but for brewing beer (obviously enough). Here's one version. The key elements seemed to be using a bottle-conditioned beer, and providing an appropriate medium for the culture.

I decided to try this, but adapting it to a starter or "mother" rather than a yeast culture for brewing, by using a well-known and widely-available Australian beer, Cooper's Pale Ale. This beer is renowned for having a cloudy character, showing that it's made with real stuff. I took two 375ml bottles stored upright, and poured most of the beer into glasses (and yes, drank it - I did get some help), then poured the last 30ml or so of each into a prepared container. I then added about 50g of wholemeal spelt flour and mixed it together. The next day I added the same proportion of beer from the bottom, and a little more spelt.

On the third day I clearly had a very active culture - I assume and hope from the beer yeast, since it was more active by a considerable margin than I would have expected if I were simply trying to begin a spelt starter with water. Although I can't rule out the spelt doing more than just feeding the mix, the results when I came to bake from it were very good, and faster than I have tended to get from sourdough starters. More on that in an accompanying post.

So it looks like you can make bread from beer at home. And yes, for the curious, there is a way to make beer from bread as well. For another day!

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