Theory 12/Food Science & Fermentation /Microbial ecology/3 min
The Winner Sets the Flavour
Complex starters are prized for their diversity. The outcome may be decided by whoever wins the first day.
The flavour of a spontaneous fermentation is set by which genus becomes dominant, and the winner is determined by the initial pH rather than by the diversity of the starting community, so flavour is predictable from a single early measurement.
01The evidence
- Fermentation has been regulated on the basis of the dominant genus, with the dominant organism shown to drive microbial succession and the resulting flavour compounds.Food Bioscience
02The tension
Spontaneous fermentations are valued for their microbial diversity, and the assumption is that diversity produces complexity. In practice, most spontaneous fermentations are dominated by one or two genera, and the diversity that remains is often metabolically silent.
03The theory
A fermentation is a competition for a limited resource under conditions that change. The organism that grows fastest under the initial conditions establishes a population advantage, and its metabolites then set the environment that selects against competitors.
That makes the winner a function of the starting conditions, particularly pH. A small difference in initial pH can change which genus wins, and therefore the flavour, even with an identical starting community.
The prediction is that initial pH should predict the dominant genus and the flavour profile better than initial diversity, and that adjusting pH should reproducibly steer flavour without changing the starter.
The practical consequence is that fermentation control should target initial conditions rather than inoculum complexity, which is both cheaper and more reproducible.
04What this is not
Those models assume that more starting diversity yields richer flavour. This assumes a winner whose identity sets the flavour, which predicts that initial pH beats diversity as a predictor.
05Predictions
- P1Initial pH should predict the dominant genus better than initial diversity.
- P2Adjusting pH should steer flavour reproducibly.
- P3Diversity should not predict flavour once the dominant genus is known.
06What would refute it
Flavour tracking diversity at fixed initial pH would restore the complexity model.
07What it would change
It would make fermentation control a pH problem rather than an inoculation problem.
08Evidence base
- Regulating fermentation by dominant genus and its effect on succession and flavour — Food Biosciencehttps://www.sciencedirect.com/science/article/abs/pii/S221242922500255X