Sweet Stiff Starter: How to Make One and Why It Makes Softer, Sweeter Sourdough

A sweet stiff starter (often shortened to SSS) is a firm, lightly sweetened levain made from your everyday sourdough starter. It is closely related to Italian lievito madre, the stiff starter traditionally used for panettone, and it is the reason many bakery-soft sourdough buns and loaves taste mild and rich rather than sour.

If your brioche, milk bread or cinnamon rolls come out dense, slow or a little too tangy, switching to a sweet stiff starter is the single biggest improvement you can make.

What makes it different?

• It is stiff. A normal starter is equal parts flour and water (100% hydration). A sweet stiff starter is around 45–50% hydration — a firm dough rather than a batter. Lower hydration favours the yeast over the acid-producing bacteria, so the flavour stays mild.
• It is sweet. A little sugar, about 20% of the flour weight, gets the culture used to a sugary environment before it meets an enriched dough, so it does not stall when it gets there.
• It is strong. A well-ripened sweet stiff starter has terrific rising power, which is exactly what heavy, buttery doughs need.

How to make a sweet stiff starter

You need about 10 minutes of work and 8–12 hours of waiting.

• 50 g active sourdough starter, at its peak
• 100 g strong white bread flour
• 45 g water at about 30°C
• 20 g caster sugar

1. Stir the sugar into the water until dissolved, then add the starter and mix until milky.
2. Add the flour and knead for 2–3 minutes into a smooth, firm ball. It will feel like a stiff bread dough.
3. Put it in a straight-sided jar or tub, press it flat, and mark the level.
4. Leave at 26–28°C for 8–12 hours until it has roughly tripled and the top is domed.

That makes about 215 g — enough for most single-loaf or tray-bake enriched recipes.

How to tell it is ready

• It has tripled in volume and the top is domed, perhaps just starting to flatten.
• When you tear it open, the inside is stretchy and full of fine strands, like a honeycomb or cobweb.
• It smells sweet and yeasty, like a bakery, not sharp or vinegary.

If it smells sour or has collapsed, it has gone too far — feed it again (one part starter to two parts flour, plus sugar and water in the same proportions) and use it at the next peak.

How to use it

Use a sweet stiff starter in place of your usual starter in any enriched recipe, at about 25–30% of the recipe's flour weight. Because it is stiffer than a normal starter, add an extra 5–10 g of liquid to the dough for every 100 g of sweet stiff starter you use.

It is ideal for soft sourdough milk bread, cinnamon rolls, dinner rolls and the brioche in our enriched sourdough guide.

Keeping a sweet stiff starter going

You do not need to keep one permanently. Most bakers build it fresh from their everyday starter the night before an enriched bake. If you bake sweet doughs often, you can keep it going by feeding it once a day at the same ratio (1 part starter : 2 flour : 0.9 water : 0.4 sugar), or store it in the fridge between bakes and refresh it twice at room temperature before using.

FAQ

Is a sweet stiff starter the same as lievito madre?

They are close relatives. Lievito madre is a stiff starter traditionally kept without sugar and used for panettone and pandoro. A sweet stiff starter adds sugar to make it more tolerant of rich, sweet doughs.

Can I make one from a rye or wholemeal starter?

Yes. Use a spoonful of your starter to seed it and build it with white bread flour. After one or two feeds it will behave like any other sweet stiff starter.

Why add sugar to a starter?

Enriched doughs are high in sugar, which slows a culture down. Getting the yeast used to sugar in the starter means it keeps working strongly when it meets the dough.

My sweet stiff starter barely rose. What went wrong?

It was almost always too cool. Sweet stiff starters like warmth — 26–28°C. Also check your everyday starter was at its peak when you built it.

Start with a lively culture

A sweet stiff starter is only as strong as the starter you build it from. Our San Francisco sourdough starter is a live culture held dormant rather than dehydrated, and is ready to bake with in about two hours.