What is the best feeding ratio for sourdough starter?

A 1:1 ratio of flour to water (by weight) is the most common and creates a 100% hydration starter. This is the easiest to maintain and what most recipes assume. Some bakers prefer stiffer starters (1:2 flour to water) for different flavour profiles.

How much starter should I keep when feeding?

Typically you keep a small amount (20-50g) and feed it with equal or greater amounts of flour and water. The smaller the amount you keep relative to the feed, the more vigorous the fermentation will be.

How often should I feed my starter?

If kept at room temperature, feed every 12-24 hours. If refrigerated, feed once a week. Before baking, take the starter out of the fridge and feed it 8-12 hours before you need it so it's active and bubbly.

Can I use wholemeal flour for my starter?

Yes, and many bakers find wholemeal or rye flour creates a more vigorous starter because the bran and germ provide more nutrients for the yeast and bacteria. You can maintain with white flour and occasionally feed with wholemeal.

How do I know when my starter is ready to bake with?

A mature, active starter should double in volume within 4-8 hours of feeding. The float test is a good indicator: drop a teaspoon of starter into water — if it floats, it is ready. The starter should also have a pleasant, mildly tangy smell and be full of bubbles throughout.

BakeCalcs

Sourdough Starter Calculator

Calculate flour and water needed to feed your sourdough starter to a target weight.

Target Starter Weight

Total weight after feeding

Flour : Water Ratio

Existing Starter to Keep (optional)

Leave at 0 if starting from scratch

How We Calculate This

Feeding a sourdough starter is about maintaining the right ratio of flour, water, and existing starter. This calculator works out the quantities based on your target weight and preferred ratio.

How It Works

Set your target total starter weight (what you need for your recipe + a reserve)
Choose a flour-to-water ratio (1:1 is standard 100% hydration)
If feeding existing starter, enter how much you're keeping
The remaining weight is split according to the ratio

Example

Target: 200g, keeping 50g starter, 1:1 ratio
Remaining: 150g, split into 75g flour + 75g water

Frequently Asked Questions

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Last updated: February 2026

All calculations are based on standard ratios and conversions. Results may vary with specific ingredients, equipment, and conditions.