What is sourdough, is it important and how do you make it?

When there is only one loaf left in the deep freeze, my usual bread making routine is to bake four 1Kg loaves, mostly because I only have four bread tins and also because the mixer can only mix 2Kg of dough at a time. The bread is made from two thirds wholemeal and one third white mixed grain flour. Occasionally I will take the sour dough leaven out of the fridge, refresh it, and make some sour dough bread but, as yet, I have not established a routine which means the house only infrequently gets the distinctive savoury aromas from baking sour dough.

Sourdough is bread made using naturally occurring yeasts living in a symbiotic relationship with a lactobacillus bacteria as the rising agent. Sourdough is how bread used to be made before commercial yeasts became commonly available. While this is important in a historical context, maintaining traditional skills, sourdough bread is possibly better nutritionally (opinions differ) than bread made with commercial yeasts and is certainly “better” than commercial bread made with the Chorleywood process.

There are two principal activities involved in preparing sourdough bread; making the starter and using a production leaven.

The starter is made by mixing some flour and water together as a thick paste, gloopy enough that it can be stirred with a spoon, leaving it overnight somewhere warm in a mixing bowl covered with cling film, adding more flour and water, leaving overnight again and repeating the process over several days until you have enough gloop to use as a leaven. I start with, perhaps, four table spoons worth of flour, adding two or three more each day and probably ending up with between 300 and 400g of gloop. The best results, i.e. when the leaven starts bubbling and smelling sour after the second day, have been with organic multigrain flour, but other people have other methods. Once the gloop has started fermenting, other types of flour can be added, I aim for a 60:40 wholemeal/wholegrain mix. Once the leaven is working, I transfer it to a larger mixing bowl and double the bulk of the mix which I then leave overnight again.

The next day, baking day, first thing in the morning, I transfer four table spoons of the leaven to a smaller bowl, double the bulk with flour and water, and put this in the fridge. This is your production leaven for next time.

Since I aim to make two 1Kg loaves, I need to do some maths, working out the ratios of flour and water that I need to add. If you are going to make cottage loaves or buns then ratios are less of an issue. About one quarter of resultant dough (2000/4=500g) needs to be from the leaven. Allowing for wastage, I aim for 600g in the large mixing bowl above, which is about right since the starter, which I doubled, was about 300g. Also, the final dough requires a flour/water ratio of 3:2, or for 2Kg dough, 1200g flour and 800g (or ml) water.

If I have 600g of leaven of which 360g will be flour and 240g will be water, I need to add (1200-360)g flour and (800-240g) lukewarm water, three teaspoons of salt and, optionally, three desert spoons of butter, then use the mixer to knead the dough. The dough is then transferred to a large, buttered, mixing bowl, covered and left somewhere warm for the first rise, waiting for the dough to, maybe, double in size. Since this is sourdough rising will is probably going to take longer than when using commercial yeast, possibly several hours, though I usually manage to leave it two or three hours before I get fed up, knock the dough down, divide in two and transfer to two baking tins for the second rise which, will again, probably take several hours before the loaves have risen enough to be popped in the oven for forty minutes at 175C. The house then fills with the lovely tangy smell of baking sourdough. It smells even better the next day when being toasted for breakfast,

When you need to make some more, the production leaven (probably about 400g) is taken out of the fridge and allowed 24 hours to wake up after which the bulk is transferred to a larger bowl, doubled to about 800g and left another day. Some is then transferred to a smaller bowl, has some flour and water added and put back in the fridge for the future. The 600g or so remaining is used as the production leaven as described above.

One of the main difficulties I used to encounter when bread making was finding somewhere warm enough to make the dough rise. I eventually solved this problem using heated pads which I had purchased for warming demijohns of fermenting wine.