Substrate sugars
Lactose in milk, sugars from cabbage, starch unlocked by koji in soy crafts.
A lactic cell takes glucose to lactate. A yeast takes it toward ethanol and CO2 — the bubbles in bread and beer.
Jars are ecosystems: salt selects, oxygen gradients form. This page is public food chemistry, not a pathogen culture guide.
Parts
Glycolysis highway
The Embden-Meyerhof path into pyruvate. Fermentation is what happens next.
End products
Lactate, ethanol, acetate, CO2, flavour molecules. Kimchi and yoghurt are lactate-forward.
Salt and water activity
Doenjang and pickles use salt to steer who may grow.
Koji enzymes
Aspergillus oryzae unlocks soy protein for doenjang-adjacent crafts.
Gas and texture
CO2 lifts bread and can burst a sealed bottle.
Life cycle
1Select the vat
Salt, temperature and starter or wild inoculation decide the opening cast.
2Acidify or ethanolise
Hours to weeks. Yoghurt is fast; doenjang is a long season.
3Ripen
Secondary microbes add aroma. Fridge kimchi keeps changing slowly.
4Eat or stall
Cold, salt and acidity stall further change.
Home cooks already know succession as a fizz or a slow sour.
Keep exploring
More in Beneficial allies
Gut microbiome
A diverse intestinal community fed by fibre — not a single ideal species list and not a wellness shop.
Familiarity 88Probiotics
Live microbes in food or capsules — strain-specific guests, not a whole microbiome and not medical advice.
Familiarity 90Skin microbiome
A site-specific living film — oily, moist and dry neighbourhoods, not a sterile wrapper.
Familiarity 62Soil microbes
The hidden workforce of land — decomposers, mycorrhizae and a mostly uncultured majority.
Familiarity 48Nitrogen cycle
How microbes move nitrogen between air, soil, water and food — plus the industrial shortcut that feeds billions.
Familiarity 40