Our Sourdough Starter

Every loaf of sourdough we bake at Krumb begins with the same thing: our live sourdough starter. It has been fed and tended every single day since we opened, and it is the quiet heart of everything we do with bread. If you love proper sourdough belfast style, knowing a little about the starter is a good place to start.

What Is a Sourdough Starter?

A sourdough starter is a living culture of wild yeast and natural bacteria. It is made from nothing more than flour and water, left to ferment over time. The wild yeast in the atmosphere and in the flour itself colonises the mixture, and the bacteria produce the lactic and acetic acids that give sourdough its characteristic depth of flavour and its keeping quality.

Unlike commercial yeast, which does one job and does it fast, a sourdough starter is complex and alive. It responds to temperature, to the flour you feed it, to the rhythm of the bakery around it. It is, in the best possible way, a little unpredictable. That unpredictability is part of what makes every sourdough belfast bake genuinely unique.

How We Look After Our Sourdough Starter

Caring for a sourdough starter is a daily commitment. Ours is fed every morning before baking begins: a portion of the old starter is kept, fresh flour and water are added, and it is left to bubble and rise before we use it in the dough.

The feeding schedule matters. Feed it too infrequently and the acids build up, making the bread sharply sour rather than pleasantly tangy. Feed it at the right time and you get a starter that is active, bubbly and full of the wild yeast needed to raise a proper loaf. We have got our routine dialled in, and the starter repays us with consistent, characterful bread every day.

We keep ours at room temperature during baking season, which suits our small-batch workflow. Temperature is everything with wild yeast: too cold and fermentation slows right down, too warm and things move faster than you want them to. Part of the craft is reading your starter and adjusting accordingly.

Why Wild Yeast Makes Better Bread

Wild yeast ferments more slowly than commercial yeast, and that slow fermentation is where the flavour lives. The long, cold overnight proof we give our doughs allows the wild yeast to work steadily, developing the complex, slightly tangy taste that sets a proper sourdough belfast loaf apart from a supermarket sliced.

The natural acids produced during fermentation also improve the bread's keeping quality. A well-made sourdough stays fresh and flavourful for longer than a yeasted loaf, and it actually improves slightly over the first day or two as the crumb sets. That is the starter doing its work.

Beyond flavour, the fermentation process makes the nutrients in the grain more digestible. Many people who find commercially yeasted bread difficult to digest get on much better with a properly fermented sourdough. We are not making medical claims here, just passing on something we hear regularly from our regulars.

From Starter to Loaf: Our Sourdough Process

Once the starter is active and ready, we build a levain: a larger portion of starter that is given one more feed before being mixed into the main dough. The dough itself goes through a series of folds during bulk fermentation, developing strength and structure without mechanical kneading.

Then comes the shaping, the final proof, and the bake in a screaming hot oven. The result is a loaf with a proper crust, an open, chewy crumb, and that signature sourdough depth of flavour that you simply cannot get from a packet of instant yeast. Every last krumb of that process matters.

Our sourdough menu changes slightly with the seasons as we play with different flour blends and additions, but the starter underneath it all stays constant. It is the one ingredient we never change.

Questions We Get Asked

Can I get your sourdough starter recipe?

Starting your own is simple in principle: equal parts flour and water, left somewhere warm, fed daily for about a week. Use strong bread flour or rye for best results. The wild yeast in your kitchen and flour will do the rest. Patience is the main ingredient.

How is sourdough different from regular bread?

The leavening comes entirely from wild yeast rather than commercial yeast. The fermentation is slower, the flavour is more complex, and the bread keeps better. It is also made without any additives or improvers, which is how bread should be.

Do you bake sourdough every day?

We bake fresh daily, Wednesday to Sunday. Our sourdough sells out most days, so if you want to be sure of a loaf, click and collect is the way to go.

Order online: Large Sourdough, Seeded Sourdough and more on click and collect.

More from the Krumb journal

• Our Sourdough: Baked Fresh Daily in Belfast
• Seeded Sourdough at Krumb
• How to Store Sourdough So It Lasts

Come and try a loaf for yourself. We are at 258 Ormeau Road, Belfast, open Wednesday to Sunday from 9am to 4pm. Order via click and collect to have your sourdough belfast loaf waiting for you, freshly baked and ready to go. Bake it nice, every day.