There are two main ways of naturally leavening or making a dough rise. The most common one used today is Saccharomyces, a cultivated form of yeast and the other, older method is using a Lactobacillus culture, usually in symbiotic combination with natural yeasts to create sourdough. Since the rise in popularity of wheat based breads which can easily be leavened with yeast alone, sourdoughs have fallen out of favour since they take a bit more work, and care is needed to look after the starter. However with a little effort, sourdough makes bread with a wonderful flavour, a longer shelf life and it has even been suggested that the bacteria can help balance your intestinal flora, ease digestion and could help with gluten intolerance.
Before you can make sourdough bread, you first have to create a sourdough starter, also called a levain. Technically all you need to create a sourdough starter is a flour, water, a jar and time, though it can be a bit tricky sometime to capture the wild yeasts and bacteria, and encourage them to create a culture where they live in complete symbiosis. You can buy starters over the Internet, which I have used, but the easiest method I have found is as follows;
Take a clean wide mouthed jar or plastic container, add 2tbsp of rye flour, about 4tbsp of clean water, mix together into a loose paste , loosely cover the container and leave. After anything between a day and 3 days you should start to smell lactic acid, which smells a bit like vinegar and see small bubbles appearing. If so then you have a sourdough starter, if not then wait a bit longer or start again. If you don’t have rye flour, try organic whole-meal, or even organic plain flour to see if that helps, but I find that rye works pretty much every time.
Once you have your starter, you now have to treat it like a pet, feeding it, pampering it and you could even give it a name if you want to. If you are not making a lot of bread you can keep it in a sealed container in the fridge. Every 3 or 4 days, take it out, remove half of it (use or discard it), add 1 tbsp of rye flour, 2tbsp of water, mix and return it to the fridge.
If you need to use some of your starter to make bread, repeat the previous procedure, but with the half you have removed, add it to a bowl with a cup (150g) of flour (this can be any type depending on the type of bread you wish to make), a cup (150ml) of water, mix, cover and leave for a day to double in size. Now you can start making your bread, remembering to take into account the weight of the starter when adding it to your recipe.
You may find that after a while you starter loses vitality and there are methods and tricks to give it a kick-start again, but since it is pretty easy to get going you can start afresh. However some sourdough starters have been passed down through the generations and some in San Francisco are over 150 years old. Sourdough makes great white breads, pizza bases, rye breads, pancakes, etc. that have far more flavour than normal breads. They are also great for making toast and have a unique texture, that is both crunchy and chewy. The Sourdough Companion has hundreds of recipes if you are interested in making any.
For anyone who doesn’t know about the sock puppets, watch this Alton Brown episode of Good Eats.