Building a Production Leaven (Sourdough Series #2)

As previously reported, I am using a rye starter to create a variety of breads. The process has three parts, essentially: first the rye starter itself, which can be happily neglected in the fridge for weeks, unlike fussier wheat starters; second the intermediate phase of producing a larger leaven with part of what will eventually be the loaf you want to bake; third comes the final dough.

Of these the last part is the most varied, and I will be posting recipes that reflect the possibilities for making a variety of sourdough breads easily (if not as quickly as familiar yeast-raised bread).

Building a leaven, the second part, involves using some of the flour(s) that you want in the final product and turning them, in effect, into a sourdough starter on a larger scale.

A great example of this and the one which sent me on this pattern of rye sourdough baking is Andrew Whitley's "Cromarty Cob", featured in Bread Matters. This was one of those discoveries that involved accident and necessity - Whitley forgot his wheat starter when he travelled to the Black Isle in Scotland (incidentally where my mother's parents came from) to run a baking class and decided to work with the rye starter he had.

Whitley's Cromarty Cob recipe involves this leaven as the basis for one cob loaf:

100g rye starter
66g stoneground wholemeal flour
66g bread flour
66g water (warm, depending on your timetable)

If you look in his book the amounts are actually 150/100/100/100, but this produces 450g of leaven (prior to any evaporation etc) and the bread recipe only needs 300g of the product. Feel free to make more and see if you can maintain it as a new starter, or make a second, smaller loaf as I sometimes do.

To make the leaven simply combine the ingredients, cover and leave somewhere warm (less warm if you don't want to move onto the dough within a few hours). The mixture will be quite sloppy (see above); depending on the power of your starter, the temperature and other factors, it will become bubbly (use a glass bowl to see this) and rise over the course of maybe 4 hours. In winter I can mix this in the morning and it's fine after work; but it is best to use it to build the dough proper before the mixture collapses back down and loses its gas.

For what to do with a leaven, try this post for a fruit bread, and this one that uses the whole of Whitley's larger 150/100/100/100 starter proportions to build a large spelt and wheat cob.