Sugar consumption and alcohol production follow predictable yeast kinetics
When yeast is pitched into a sugar solution (grape must for wine, grain for beer, honey for mead), sugar concentration drops exponentially as yeast consumes it. Alcohol concentration rises at a roughly proportional rate: yeast converts glucose into ethanol and CO2 through glycolysis and fermentation. The curve shows a lag phase while yeast acclimates, an exponential growth phase where consumption is fastest, and a plateau when yeast either runs out of sugar or alcohol levels become toxic.
The final alcohol content depends on starting sugar concentration and yeast tolerance. Wine yeasts stop around 15-18% ABV; ale yeasts around 8-12%; mead yeasts can push to 20%+. The plateau represents the equilibrium point: either no sugar remains, or alcohol concentration has suppressed yeast activity.
Fermentation timing and flavor development
The steep middle section of the curve (active fermentation) lasts days to weeks depending on yeast strain, temperature, and sugar concentration. During this phase, yeast generates flavor compounds like esters and phenols. Once the curve plateaus, fermentation is complete or dormant. Cold storage can reactivate dormant yeast or slow fermentation, extending the flavor development phase. Stopping fermentation early (by cooling, filtering, or adding sulfites) preserves residual sweetness.