Starter feeding calculator
Tell it how much starter your recipe needs and how fast you want it ready. You get the grams of starter, flour and water to mix, with a little left over to keep.
A little extra also covers what sticks to the jar.
Feed
- Starterfrom your jar
- 24g0.8 oz
- Flour
- 48g1.7 oz
- Water
- 48g1.7 oz
Makes 120 g at 100% hydration
Usually peaks in 6–8 hours at about 75°F (24°C)
Choosing a feeding ratio
The ratio is starter : flour : water by weight. More fresh food per gram of starter means the yeast and bacteria take longer to eat through it, so the starter peaks later. Use that to line the peak up with your mixing time.
| Ratio | Typical time to peak at 75°F (24°C) | Good for |
|---|---|---|
| 1:1:1 | 4–6 hours | Feeding in the morning to mix in the afternoon |
| 1:2:2 | 6–8 hours | A relaxed same-day bake |
| 1:5:5 | 8–12 hours | Feeding at night to mix in the morning |
| 1:10:10 | 12–16 hours | Long gaps or a warm kitchen |
These are typical ranges. Every starter is a little different, so watch yours for a few feeds and adjust.
Feeding for exactly what you need
If your recipe needs 100 g of starter, feed for a bit more than that. Some always sticks to the jar and spoon, and you need a spoonful to keep the culture going. The calculator adds your “extra to keep” on top before splitting the total into starter, flour and water. Plug the starter amount into the sourdough calculator to build the rest of the recipe.
Stiff or liquid starter
Equal flour and water by weight gives a 100% hydration starter, the most common kind. A custom ratio like 1:2:1 makes a stiff starter at 50%, which ferments more slowly and tastes milder. Set Custom to try it.
Questions bakers ask
What does 1:2:2 mean?
One part starter, two parts flour and two parts water by weight. 20 g of starter fed with 40 g of flour and 40 g of water is a 1:2:2 feed, and it makes 100 g of starter at 100% hydration.
Which feeding ratio should I use?
Pick the ratio that makes your starter peak when you want to mix. 1:1:1 is fast, good for a same-day bake. 1:5:5 or 1:10:10 is slow, good for feeding at night and mixing in the morning.
How do I know my starter has peaked?
It has roughly doubled or more, the top is domed or just starting to fall, it’s full of bubbles, and it smells pleasantly sour. Use it at or just before the peak.
What do I do with the discard?
Anything left in the jar that you don’t feed is discard. Keep it in the fridge for crackers, pancakes or waffles, or compost it. Feeding only what you need, as this calculator does, keeps discard small.
Does temperature matter?
A lot. The peak times shown are for about 75°F (24°C). A cooler kitchen can take much longer and a warmer one can be noticeably faster. Warm water and a warm spot speed things up.