Ingredients
- Strong white flour
- Tepid water (freshly boiled water mixed with cold tap water until it’s slightly warm)
Equipment
- 0.5 litre Kilner-style glass jar
- A small silicon spoon or spatula for scraping the sides of the jar/mixing the starter
- Accurate kitchen scales to weigh your flour and water
Creating your starter
Day 1 – Wash the jar, dry it and add 50g flour and 50g tepid water. Mix well and leave with the lid slightly open at room temperature. The yeast particles that naturally occur in the flour and the air will feed on the flour and water. The process generates gas, so don’t seal the jar otherwise it will potentially be under too much pressure.
Day 2 – Add another 50g flour and 50g tepid water to the jar, mix well and leave with the lid slightly open at room temperature.
Day 3 – Repeat Day 2
Day 4 – Stir the starter well and discard 100g. Top up with 50g flour and 50g tepid water, mix well and leave with the lid slightly open at room temperature.
Days 5 to 7 – Repeat day 4 each day
By now your starter should be bubbling nicely and have a mousse-like texture when you first stir it.
To check if it’s ready to use, take a tiny amount and drop it in a glass of cold water:
- If it floats, it means it’s ready to use.
- If it sinks immediately, it’s not ready. Carry on feeding it for a few more days before testing it again.
Keeping your starter alive
If you store your starter at room temperature, you will need to feed it every day by following the instructions for Day 4 of “Creating your starter”. If you aren’t going to bake with it for a few days, you can keep it in the fridge with the lid shut without having to feed it daily, but you will need to feed it at least once a week to keep it alive.
If you need more than 100g of starter for your sourdough, you can feed it a bit more flour and tepid water after you’ve taken out the amount you need, but don’t add loads in one go as it will swamp the existing starter and possibly kill it off. Instead, add the usual 50g flour and water, then do the same the following day without discarding any.
Don’t worry if your starter has separated out slightly – a layer of greyish liquid on the top just means it’s ready for a feed.
If it smells sour/slightly vinegary, that’s normal too.
Baking with your starter
When you’re ready to use your starter, take it out of the fridge, add 50g flour and 50g tepid water, give it a good stir, and leave it at room temperature with the lid slightly open. It should be ready to use in 8-10 hours.