How to make a sourdough starter and delicious sourdough bread

Humans

To make your own sourdough bread, you need to create an environment where wild yeast and bacteria want to hang out. Sam Wong explains how

By Sam Wong

4 March 2020

What you need

White and wholemeal flour
Water
Salt
Glass jar with lid
Casserole pot

IF YOU buy yeast, you get one species: Saccharomyces cerevisiae, a reliable and predictable bread-maker. But for most of history, humans have used a living culture of wild yeasts and bacteria to produce bread.

We call this bread sourdough, and the culture a starter. You could get an established starter from someone else, but it is very easy to make your own. All you have to do is create an environment where wild yeasts want to grow.

Some of the microbes you need will be in the flour already. Others, particularly bacteria, may come from you. In a recent study, researchers sent the same flour and starter recipe to 18 different bakers. They found in the resulting starters, and this was reflected in the flavour of the bread.

To make yours, mix 50 grams of wholemeal flour and 50 millilitres of water in a jar, then cover it with a loose lid and leave it in a warm place. Bubbles should appear after a few days, meaning your starter is active. If nothing is happening, throw away half of the mix and replace it with fresh flour and water. This is called feeding the starter. Once your starter is active, feed it like this every day for at least a week before baking with it.

The sourness in sourdough comes from lactic acid-producing bacteria, the same group that we recruited last week to make kimchi. The acid keeps unwanted microbes away, but Candida milleri and other yeast species don’t mind it. Don’t be alarmed if, at some point, the starter smells of nail polish remover. The bacteria sometimes produce acetone, but this won’t end up in your bread.

The night before baking, take 50g of starter and whisk it into 350ml of water. Measure 500g of strong bread flour – I like to use half white and half wholemeal – add 9g of salt, then mix in the diluted starter. Leave this for half an hour until it is less sticky, then shape it roughly into a ball. Cover with plastic and leave it in a cool place overnight, as you want the fermentation to proceed slowly.

By morning, the dough should have expanded. If you poke it, it should spring back partially, but an imprint will remain. Now shape the loaf – this can be tricky so you might want to look for tips online – or put it in a tin, then leave it to prove for another hour or two.

Preheat the oven to 230°C with a lidded casserole pot inside. Baking inside a pot traps steam, which delays crust formation and lets the bread expand more. Alternatively, bake it on a flat tray with a bowl of hot water on the shelf below.

When the loaf is proved, lower it carefully into the pot and slash the top with a knife to help the dough expand. Bake for 20 minutes with the lid on, then 30 more with it off.

Keep your starter in the fridge and feed it once a week when you aren’t baking. Take it out a day before you want to bake and give it a feed. You can keep doing this indefinitely.

For next week

Garlic

Lemon

Oil

Salt

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