Sourdough UK vs US: The Differences Between American and British Sourdough Jargon

Sourdough might be a global obsession, but the way we talk about it depends entirely on where you’re baking. If you’ve ever followed an American sourdough recipe in a UK kitchen (or vice versa), you’ve probably found yourself pausing at unfamiliar terms like “all-purpose flour” or “baker’s percentage.”

Don’t worry — it’s not you. The world of sourdough is full of jargon, and the language can vary wildly between British and American bakers. Here’s a guide to the key differences, so you can translate on the fly and get back to baking.

1. Flour Confusion:

Strong vs. All-Purpose vs. Bread Flour

UK:

Strong white flour – High-protein flour ideal for bread-making

Plain flour – Lower protein, used for cakes, biscuits, sauces

Wholemeal flour – Whole wheat flour, includes the bran and germ

US:

Bread flour – High-protein, similar to UK strong white flour

All-purpose flour – Medium protein, a catch-all used for most baking

Whole wheat flour – Equivalent to UK wholemeal

Tip: If a US recipe calls for “all-purpose flour,” don’t swap it directly for UK plain flour in a sourdough recipe — it often won’t have enough gluten strength. Use strong white flour instead.

2. Sourdough Starter: Levain vs. Leaven vs. Preferment

American recipes love using terms like levain or leaven, especially when describing a portion of starter that’s built specifically for a bake.

US:

Levain/leaven – A fresh mixture of starter, flour, and water built to raise one loaf Sourdough starter – The mother culture you feed regularly

UK:

Starter seems to be the go-to word for everything — whether it’s the culture you keep or the portion you’re using

It is the same concept, just different levels of detail. In the UK, we’re a bit more casual with terminology.

3. Feeding Ratios and Percentages

US bakers often use baker’s percentages: flour is always 100%, and all other ingredients are given as percentages relative to that.

UK bakers may use baker’s percentages too, but are more likely to work with straight-up weights in grams (or ounces).

Example:

American recipe: “Use 100% hydration starter”

UK recipe: “Feed your starter equal parts flour and water by weight”

They mean the same thing. Just don’t confuse hydration percentage with water content by volume, it’s always weight-based.

4. Proofing vs. Proving

Classic British vs. American language divide:

UK:

Proving – The time your dough rests and ferments

US:

Proofing – Same thing, different spelling

You’ll also hear “bulk fermentation” on both sides of the Atlantic. That’s the first rise after mixing, before shaping.

5. Scoring vs. Slashing

UK & US:

Both use scoring, but you might also see “slashing” in American recipes. Both refer to the cuts you make on the dough before baking to control the oven spring

Bonus term: Lame (pronounced “lahm”) — the curved razor tool used for scoring. Used in both countries but sounds way more common in US home baking circles.

6. Temperature Talk: Fahrenheit vs. Celsius

This one catches UK bakers out constantly. American recipes list oven temperatures in Fahrenheit and often ferment at “room temp,” which they assume to be around 75°F (24°C).

British bakers work in Celsius, and our kitchens are often much cooler, especially in winter.

A “room temp” proof in an American recipe might be painfully slow in a UK kitchen. Always check the actual temperature of the dough, not just the vibe.

In Summary:

British and American sourdough bakers are doing the same thing — just speaking slightly different dialects. Once you get the hang of the terminology, the process is exactly the same: flour, water, time, and a bit of patience.

So whether you’re feeding a starter or building a levain, proving dough or watching it rise, just remember: sourdough speaks many languages but the end goal is always the same.

“Delicious bread”

Got a favourite British vs. American sourdough term? Share it below — or let us know which ones still confuse you!