Fermentation Temperature Calculator
Calculate optimal fermentation temperatures for bread, beer, wine, yogurt, and other fermented foods.
Get timing estimates.
Fermentation Temperature is the single most important variable controlling the speed and flavor of fermentation. Too hot and you get off-flavors or kill the culture. Too cold and fermentation stalls.
How Temperature Affects Fermentation: Most fermentation organisms (yeast, bacteria) have an optimal temperature range. Activity roughly doubles for every 10°F (5.5°C) increase within the viable range.
Optimal Temperature Ranges:
| Product | °F Range | °C Range | Notes |
|---|---|---|---|
| Bread yeast | 75–80°F | 24–27°C | Faster rise; cooler = better flavor |
| Sourdough | 75–82°F | 24–28°C | Warmer favors yeast; cooler favors lactobacilli |
| Beer (ale) | 60–72°F | 15–22°C | Strain-dependent |
| Beer (lager) | 45–55°F | 7–13°C | Low and slow for clean flavor |
| Wine | 55–75°F | 13–24°C | White wines cooler, reds warmer |
| Yogurt | 108–115°F | 42–46°C | Thermophilic bacteria |
| Kombucha | 75–85°F | 24–29°C | SCOBY prefers warmth |
| Sauerkraut | 65–75°F | 18–24°C | Cooler = crunchier, better flavor |
| Kimchi | 65–75°F | 18–24°C | Initial room temp, then refrigerate |
| Tempeh | 85–90°F | 29–32°C | Rhizopus mold needs warmth |
Timing Estimates: Fermentation time varies inversely with temperature within the safe range. A rough rule: for every 10°F (5.5°C) below optimal, expect fermentation to take about 1.5–2x longer.
Practical Example: Bread dough at 80°F (27°C) may rise in 1 hour. The same dough at 65°F (18°C) might take 2–3 hours, but will develop more complex flavor.
Cold Fermentation: Many bakers and brewers deliberately use cold temperatures (38–50°F / 3–10°C) to slow fermentation over 12–72 hours. This technique, called “retarding,” develops deeper flavors.
Tips:
- Use an instant-read thermometer to check dough and liquid temperatures.
- Ambient room temperature is not the same as dough/liquid temperature.
- A slightly warm oven (turned off, light on) creates a good proofing environment around 78–80°F (25–27°C).
- In cold kitchens, place ferments near a heat source or use a fermentation heating mat.