100% rye with active sourdough and a little yeast

Check the culture first

A smooth, dark liquid layer can be hooch; it establishes neither mold nor readiness. Discard the entire culture if you see mold, fuzzy growth, pink/orange patches or notice a putrid smell. Don't salvage starter from a contaminated jar or taste the raw mixture. Starter assessment guide.

For an unfed starter without signs of spoilage, pour off the liquid and move 20 g starter into a clean jar with 20 g rye flour and 20 g water. Cover with a lid that lets gas escape. At about 26°C, look for predictable growth and a pleasantly sour smell after feeds; recovery may need several cycles. Eight elapsed hours alone don't make it active. To increase the quantity, keep feeding at 1:1:1 until you have the required 180 g; this preparation is outside the recipe's timing.

For purchased sourdough, use a live culture activated according to its manufacturer's instructions, at the hydration required here. Inactive powder or flavouring extract doesn't replace 180 g of live culture. For an entirely rye loaf, the seed culture also needs to be rye.

Build the starter · approximately 4–8 hours

Mix 180 g active starter + 180 g flour + 180 g water. Cover and mark the level. Aim for about 26°C in the mixture, in a spot whose temperature you've measured; adjust water temperature for the flour and room. Don't use a switched-⁠on oven or put the jar beside a hot surface.

Use when well aerated, clearly risen and pleasantly sour, near peak rise. The window comes from a 1:1:1 feeding trial, adapted here to rye. It guarantees neither bacterial numbers nor the acidification of this formula. If still inert or smelling only of wet flour at eight hours, don't proceed as though it were ripe.

Already have 540 g ripe rye sourdough at 100% hydration? Start directly with the final dough.

Mix and fill the tin · 10 minutes

Disperse the starter in 205 g water. Add 280 g flour, 12 g salt and 3 g instant yeast, mixing vigorously until no dry patches remain. Expect a thick, sticky paste. Don't add flour in pursuit of an elastic dough ball.

Transfer directly to the greased or lined tin. Smooth with a wet spatula and add optional sesame. Mark the starting level. No stretch and folds or separate bulk rise needed.

Proof · approximately 60–120 minutes

Cover without touching the surface and keep at about 26°C. Look for roughly 50% expansion, small bubbles and fine surface cracks. It doesn't need to double. Yeast, flour and starter condition can change the timing considerably; bake before it collapses. Start preheating the oven about 30 minutes before baking.

Bake · approximately 50–60 minutes

In a preheated conventional oven: 20 minutes at 250°C, then 30–40 minutes at 220°C. Shield with foil if it colours too quickly. The centre should reach about 97–99°C; extend the bake as needed. Core temperature checks baking, not adequate sourdough acidification.

Cool · at least 12 hours

Remove from the tin and leave on a rack for 12–24 hours before slicing. Freeze spare slices after cooling. Don't shorten this stage to see whether you saved time earlier.

Fermentation and digestion

Keep the live culture and an actual fermentation stage, then add yeast to help the rise. A human study that included sourdough-plus-⁠yeast bread measured effects on gastric emptying. However, it used wheat, other cultures and another formula; it doesn't validate this rye loaf's digestive effects.

The 4–8 hours are a planning window for starter ripening, not a duration that guarantees better digestion. About 49% of the flour ferments in the starter; the rest joins only for the final proof. The culture's age isn't the fermentation time of the entire loaf.

For bloating and gas, residual fructans and mannitol matter too, rather than bacterial numbers alone. In the rye clinical trial, a specialised low-⁠FODMAP process differed from ordinary sourdough. This recipe reproduces neither that process nor a measured FODMAP result. Arbitrarily extending it to 24–72 hours doesn't establish digestive equivalence either.

What stays from the old formula

Totals: 550 g rye flour + 475 g water + 12 g salt + 3 g yeast. That's 86.4% hydration, 2.18% salt and 0.55% yeast. About 49% of the flour passes through the sourdough stage, compared with roughly 9% previously. That changes fermentation and can change sourness and crumb despite matching totals.

Acidification matters for rye bread structure; more bubbles don't measure it. IREKS explains the technology. Even a pH measurement isn't a bacterial census. This recipe promises no maximum count, digestive effects or live bacteria after baking.

The story, sources and distinction between yeast and lactic fermentation are in the blog post.