Simple sourdough starter

True sourdough breads are made using a starter that contains a culture of naturally occurring yeasts and lactobacilli or lactic acid bacteria. The yeasts produce carbon dioxide (CO₂) that makes the bread rise and the bacteria produce lactic and acetic acids that affect characteristics including taste, texture and sourness of the finished bread. In the right quantity, the acids also act as a preservative, slowing the onset of mould – a much more natural method than the spraying of calcium propionate that many modern factory loaves get.

From a hundred or more species of yeasts, saccharomyces cerevisiae (brewer’s sugar fungus) is the one usually predominant in sourdough cultures, the same species that’s sold as fresh, dried or instant bakers’ yeast. The main difference is that these industrialised versions are specific strains that have been bred (or even spliced together using GM technology) for characteristics such as speed and/or volume of CO₂ production. These are then grown as monocultures, often on molasses.

Various instructions or recipes for making sourdough starters, leavens or whatever name you choose, call for ingredients such as yoghurt, grape skins or other fruits. Whilst there is a good reason behind some of these (live yoghurt contains lactic acid bacteria and yeasts adhere to grape skins) they are not necessary as colonies of both live on the skins of grains. The argument that those best suited to feeding off cereals (and producing CO₂ and acid as by products) are the ones found living on them is a very persuasive one.

The recipes also often call for varying amounts of water and flour at each stage (or refreshment) and for portions of the mixture to be thrown out along the way.

The following is both simple and effective. Rye grains apparently host very large microbe populations and certainly, testing this recipe has produced a very active starter that’s made a mess of my kitchen worktop more than once. As the yeasts live on the outside of the grain, your chances improve when using wholemeal flour, preferably from organic farms where they will have used less or no fungicide.

A plastic container with a lid is convenient for storage and if your starter gets frisky, the lid will simply pop off, where a glass jar with a screwtop or metal clip seal could crack or shatter.

Recipe/method

Day one

30g rye flour
30g water (at about 20°c)

Mix together and leave at room temperature (again about 20°C) for 24 hours.

Day two

Mix in another 30g of flour and 30g of water and leave for another 24 hours.

Days three, four, five and six

As day two.

Notes

For the first few days, the mixture might seem lifeless and could smell a bit iffy. Don’t worry about this as by day four or five, it should start bubbling and the smell will develop into something yeasty, slightly acidic and maybe even floral.

If your starter is a bit lethargic (it will take longer in a cooler room and some flour will have lower amounts of, repeat the refreshment for another day or two until it comes to life.

You can then use some of the starter straight away or keep in the fridge until needed.

Caring for your starter

Give it a name. You can’t call yourself a proper sourdough nut if you don’t.
Get to know it. Starters all have varying acidity, tastes, aromas and speeds at which they ferment.
Unless you are using it every single day, keep it in the fridge
Each time you use some of the starter, simply replace with an equivalent quantity of flour and water
When refreshing, feel free to experiment with different ratios and total amounts of flour to water in your refreshments: a looser starter will ferment more quickly than a stiff one; refreshing more often or adding a large refreshment will dilute the taste and acidity
Though you can use the rye starter for wheat breads, if you prefer 100% wheat, you can convert it by replacing the rye in refreshments with wheat flour (white or wholemeal) until it is all wheat. Either that, or get a separate wheat starter going
Forget it. Unlike other members of your household, your starter will be very forgiving of neglect. Though it will be happy to help you bake bread once a week or even daily, your starter can be left untouched at the back for the fridge for weeks or even months. The yeast and bacteria populations will decline over time but enough will live on in a dormant state. To revive, simply add flour and water and leave for up to 24 hours or until it’s bubbling again

For more on sourdough, click here.