How to refresh a sourdough starter
One of the most confusing aspects of sourdough is the maintenance and feeding of a starter. Often the feeding regime is complicated and convoluted. So let’s start with the first thing. Not all flours take the same amount of time to reach their peak. Often this is one of the key things that makes life complicated. So the rule of thumb for each is:
- Rye is the fastest and peaks after about 3 hours.
- Wholemeal flour peaks after about 4 hours.
- White roller milled flour is ready in 8-10 hours.
- Chocolate starter is slower, it peaks at about 12 hours.
I often use my french white or chocolate because the timing fits in with the retarded schedule perfectly.
I use my Rye or wholemeal for enriched doughs as this suits the timings at the Sourdough School.
I cannot stress enough the importance of getting to know your flour as different flours ferment at different rates. Depending on the amount of enzymes and nutrients available to the microbes. This is the timing for a white sourdough starter. Generally the wetter starters are more lactic, and sweeter, and white roller milled flour ferments at a moderate rate. 8 – 12 hours of fermentation gives you an optimal microbial colony that is ready to make a leaven with and then transfer to the fridge ready for the next time you bake.
- 25g Starter
- 100g Water
- 100g Flour
A standard 100% hydration refreshment (sometimes called a 1:1) – Refreshment for starters
It is absolutely imperative before you started baking that you reactivate your starter. To do this you simple remove the mother from the fridge. She will smell sour but not unpleasant. Don’t worry if there is a hooch on top, just stir it back in, or if it is very old pour it away.
Put 25g of your starter (a tablespoon) into a jug or sterile jar.
Add to this 100g of water (generally I use warmer water at 35°C to encourage the sweeter homofermentative LAB in our white starter) stir well and then stir in 100g of white roller milled flour. If you choose to use stoneground, it will ferment slightly faster so it will generally be ready to use after 6 – 8 hours.
Leave the jar in a cool but not cold area until the starter has doubled (please see timings guide above).
This way the yeast and bacteria colonise the mixture and it will be ready to make a leaven. Your starter is at her microbial peek and now needs to go back into the fridge until the next time. Please always remember not to use every last bit, as you need some to build a new starter back up. Your old starter discard is now redundant – but you can use it in lots of other baking, and it is especially good to use in rye bread. Transfer your starter to a clean, sterile jar and keep it covered, but not airtight, in the fridge at about 5°C/41°F and feed it every week. We have our classroom at an ambient room temperature of about 20°C – 22°C (or 68°F – 72°F)
On rare occasions, a starter can get bacteria in it from elsewhere and will smell horrible or the bread may taste unpleasant. This happens when the bacteria that have occupied your starter are not the right kind, and the lactic acid, which makes the starter inhospitable to other organisms, hasn’t got going or the acidity has dropped.
Discard it and start again, moving the location of your culture to a different room.
Refresh your starter at least once a week, even if you are not baking. Always refresh your starter the day before you bake – and if you can refresh it twice back to back. It will make all the difference.