Sauce Reduction Calculator
Calculate how much liquid to reduce a sauce by percentage or target volume, and how long it will take at a simmer.
Reduction Result
The Science of Sauce Reduction
Reducing a sauce means simmering it until water evaporates, concentrating flavors and thickening the liquid. It’s one of the most fundamental techniques in professional cooking.
What Happens During Reduction
When you simmer a liquid, water molecules escape as steam. The non-water components — sugars, proteins, starches, acids, and fats — stay behind. This concentrates flavor intensity and changes viscosity (thickness).
Common Reduction Targets
| Reduction | Remaining | Use |
|---|---|---|
| By 25% | 75% remains | Light sauce, soups |
| By 33% | 67% remains | Standard wine or stock sauce |
| By half (50%) | 50% remains | Demi-glace, rich pan sauce |
| By two-thirds | 33% remains | Syrup, glaze, balsamic drizzle |
Evaporation Rate
The rate of evaporation depends on:
- Pan surface area — Wider pans evaporate faster than narrow pots
- Heat level — A vigorous simmer evaporates 150–250 ml per minute from a wide sauté pan
- Starting volume — Small volumes reduce faster
Approximate evaporation rate (vigorous simmer, wide pan):
- Wide sauté pan (28–30 cm / 11–12 in): ~200 ml per minute
- Medium saucepan (20 cm / 8 in): ~100 ml per minute
- Small saucepan (16 cm / 6 in): ~50–60 ml per minute
Tips for Perfect Reductions
- Start with cold or room-temperature liquids — add them to the hot pan and bring to a simmer.
- Never add salt until after reduction — the sauce can become over-salted as volume decreases.
- Swirl the pan occasionally to prevent burning on the edges.
- Test thickness by spooning — it should lightly coat the back of a spoon for a sauce consistency.
- Remove from heat just before reaching your target — the sauce continues reducing off-heat.
Metric and Imperial Reference
| Amount | US Cups | Imperial |
|---|---|---|
| 250 ml | 1 cup | ~8.5 fl oz |
| 500 ml | 2 cups | ~17 fl oz |
| 1 liter | 4 cups | ~34 fl oz |