IN Brief:
- AB Mauri has reached full production at the UK liquid sourdough facility identified as the country’s largest by parent ABF.
- The operation expands industrial supply capability for fermented bakery ingredients, although site-level capacity figures have not been disclosed.
- ABF continues ingredients investment despite weaker demand and lower divisional operating profit in its latest financial year.
AB Mauri has brought a new UK liquid sourdough plant into full production, extending its manufacturing capacity for fermented bakery ingredients. Parent company Associated British Foods (ABF) describes the facility as the largest of its kind in the country. The operational milestone appeared in ABF’s annual results on 3 November, covering the 52 weeks ended 12 September 2026, following a programme of investment in bakery and specialist ingredients.
The plant has progressed beyond commissioning to full production, although ABF has not disclosed its location, installed capacity or project cost. That leaves the volume available for sale unspecified, even as the group identifies the new operation as part of its expansion into a growing ingredients segment. The amount of sourdough available to customers will depend on the plant’s actual operating rate and the product mix it manufactures.
Liquid sourdough normally begins with controlled fermentation of flour and water. Yeasts and lactic acid bacteria develop acidity and flavour compounds, with the final ingredient’s properties shaped by raw-material composition, fermentation time, temperature and microbial activity. Industrial production also requires repeatable hygiene and storage conditions so batches retain consistent characteristics. These are standard sourdough processing requirements; ABF has not released the UK plant’s equipment specification or proprietary process details.
A bakery using a prepared liquid sourdough adds a fermented component during dough preparation instead of generating the whole flavour profile in its own fermentation system. The ingredient changes the water balance and acidity of the formulation, while its addition rate can interact with yeast activity, flour characteristics and proofing conditions. Trials of finished products are therefore needed to establish dough handling, crumb and flavour performance across different bakery lines. Greater ingredient supply does not remove that formulation work.
AB Mauri’s range includes yeast, bread improvers, dough conditioners, bakery mixes and concentrates alongside sourdough ingredients. Liquid and dry formats also place different demands on factory logistics: pumpable materials may be metered from containers or tanks, whereas dry products generally use powder handling and dosing equipment. Cleaning, storage and product traceability have to be matched to the chosen format. The group has not specified how the new plant will pack or distribute its output.
The start-up coincides with weaker profitability across ABF’s Ingredients division. Its sales rose 2% at constant currency in the latest financial year, while adjusted operating profit declined 8% and the adjusted margin was 11.3%. ABF attributed the pressure principally to softer US bakery ingredient demand and continued spending on specialist ingredients and commercial capabilities. Capital investment totalled £245 million across the entire Ingredients division, not solely the UK sourdough project.
AB Mauri’s own profit declined as weaker consumer spending reduced demand among US customers, while some alcoholic beverage producers bought less specialty yeast. ABF said most other markets and product categories performed well, supported by its distribution network and bakery ingredient development. The UK facility has entered production after a multi-year investment cycle, even as demand for bakery ingredients varies between markets.
The group’s other bakery investment includes a fresh yeast plant in India, where commissioning remains under way and the market is expected to grow. ABF’s specialist ingredients operations have separately completed added yeast extract capacity in Germany and enzyme blending capacity in Finland. Those German and Finnish projects support different product lines from the UK sourdough plant. The projects expand distinct ingredient manufacturing streams rather than adding a single type of bakery capacity.
Producing a liquid fermented ingredient at industrial scale depends on batch reproducibility as much as total volume. Variations in acidity, microbial activity or ingredient composition can affect the dough development and fermentation behaviour seen at the customer’s bakery. A manufacturing specification can control the incoming ingredient, but mixing, proofing and baking still influence the finished loaf. Consistent product characteristics and reliable deliveries are therefore central to how the additional plant capacity can be used.
Liquid ingredient distribution adds its own constraints after fermentation. Suitable containment, transport temperatures, shelf-life limits and customer storage arrangements depend on the product formulation and microbiological specification. Bakery scheduling can be affected by the size of each delivered batch and the time available to use it. Customer deliveries will need to match each product’s shelf life and bakery batching schedule if the added capacity is to be used consistently.
ABF expects further commissioning activity in its 2027 financial year, notably at the Indian fresh yeast plant. Its UK sourdough facility is already operating, giving AB Mauri another source of manufactured fermented ingredients. Subsequent results may establish the production volumes and commercial contribution of the new plant, which were not disclosed in the annual figures published on 3 November.
