Sourdough School opens second PROVEN 12-week bread programme

The Sourdough School launched its second cohort of PROVEN, a 12-week "Bread designed for your biology" programme, with deliveries and live sessions beginning in mid-January. Enrollment for this intake closed in early January; the course began rolling out handcrafted, long-fermented high-fibre loaves the week of January 12, 2026, while weekly live workshops started shortly thereafter.

Designed as a hybrid learning and intervention model, PROVEN combines practical baking instruction with structured physiological monitoring. Participants receive weekly loaves made from regeneratively grown, stone-milled flours, featuring diverse botanicals and extended fermentations, standard practice in the programme is an 18-hour fermentation to develop flavour and break down complex carbohydrates. Alongside the bread deliveries, the programme runs live workshops each week and asks participants to keep structured symptom and food logs so they can observe any bodily changes over the 12-week span.

Programme materials describe a clinical-style protocol developed from prior dietary intervention work. That framework guides the weekly curriculum and the tracking regimen, giving participants a consistent dietary baseline and a repeatable method for measuring changes in digestion, energy and tolerance. The emphasis on stone-milled flours and regenerative grain sourcing highlights both flavour and the programme’s focus on fibre and food-system stewardship.

Practical details are front and centre for UK participants: ordering and enrolment logistics, delivery schedules and programme components were set up for domestic delivery, and the materials include clear contraindications for people with certain medical conditions. The combination of doorstep loaves and live instruction lowers the barrier for those who want to test a long-fermented, high-fibre approach without sourcing speciality flours or mastering every step of production at home.

For the home-baking community, PROVEN is notable for turning a popular artisanal technique into a repeatable, monitored dietary experiment. It offers a template for how sourdough baking can be used beyond taste and crust, providing consistent, long-fermented loaves as an intervention, and pairing them with data collection so bakers and non-bakers alike can track real-world effects.

If you missed this intake, verify enrolment and delivery details with the Sourdough School for future cohorts; in the meantime, try lengthening your own fermentation toward the 18-hour mark and experiment with stone-milled, higher-fibre flours to see how they change your loaf and your digestion over time.