# Sourdough Starter Calculator

Calculate sourdough starter feeding amounts by weight. Enter your desired total and feeding ratio to get exact flour and water measurements with timing estimates.

## What this calculates

Take the guesswork out of feeding your sourdough starter. Enter how much starter you need and your preferred feeding ratio, and the calculator will give you exact weights for starter, flour, and water. It also estimates peak time based on your kitchen temperature.

## Inputs

- **Desired Total Starter** (grams) — min 0 — Total starter weight you want after feeding. Most bread recipes need 50-200g.
- **Starter Ratio Part** — min 1, max 10 — The starter portion of the ratio (e.g. 1 in 1:2:2)
- **Flour Ratio Part** — min 1, max 20 — The flour portion of the ratio (e.g. 2 in 1:2:2)
- **Water Ratio Part** — min 1, max 20 — The water portion of the ratio (e.g. 2 in 1:2:2)
- **Room Temperature** — options: Cool (60°F / 15°C), Mild (68°F / 20°C), Room Temp (72°F / 22°C), Warm (78°F / 25°C), Hot (85°F / 29°C) — Warmer temperatures speed up fermentation

## Outputs

- **Existing Starter**
- **Flour**
- **Water**
- **Feeding Ratio** — formatted as text
- **Estimated Peak Time** — formatted as text
- **Feeding Frequency** — formatted as text
- **Starter Hydration** — formatted as text

## Details

Common feeding ratios (starter:flour:water):

  - 1:1:1 -- everyday maintenance, peaks in 4-6 hours at room temp

  - 1:2:2 -- slightly longer ferment, more food for the culture, peaks in 6-8 hours

  - 1:5:5 -- long ferment, great for overnight or before a bake, peaks in 8-12 hours

  - 1:10:10 -- very long ferment, useful for warm climates or weekend baking

Temperature and timing:

  - 60-65F: slow fermentation (12-24 hours to peak)

  - 68-72F: moderate (6-10 hours to peak)

  - 75-80F: fast (4-6 hours to peak)

  - 80-85F: very fast (3-5 hours to peak)

Hydration explained: A 100% hydration starter (equal parts flour and water by weight) is the most common. It should have the consistency of thick pancake batter. Stiffer starters (less water) ferment more slowly and develop more acidic flavor. Wetter starters ferment faster and taste more mild.

## Frequently Asked Questions

**Q: What ratio should I use for my sourdough starter?**

A: For daily maintenance, 1:1:1 is simple and works well. If you bake in the morning, try 1:5:5 the night before so it peaks overnight. In warm kitchens (above 76F), use higher ratios like 1:3:3 or 1:5:5 to slow fermentation and prevent over-proofing between feedings.

**Q: How do I know when my starter has peaked?**

A: A peaked starter will have roughly doubled in size, have a domed top (not collapsed), smell pleasantly sour and yeasty, and be full of bubbles. If it has started to sink or collapse in the middle, it is past peak and the yeast is running out of food.

**Q: Can I use the discard?**

A: Absolutely. Sourdough discard is great for pancakes, waffles, crackers, pizza dough, and many other recipes. Discard does not need to be at peak activity since the recipe typically uses baking powder or baking soda for leavening instead of relying on the starter's yeast.

**Q: How do I store my starter if I do not bake often?**

A: Feed your starter, let it sit at room temperature for 1-2 hours, then put it in the refrigerator. It will stay healthy for 1-2 weeks without feeding. When you want to bake, take it out, feed it at room temperature 2-3 times over 24-48 hours until it is rising predictably again.

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Source: https://vastcalc.com/calculators/everyday/sourdough-starter
Category: Everyday Life
Last updated: 2026-04-08