Swap between fresh and dried herbs accurately.
The general rule: 1 tablespoon fresh = 1 teaspoon dried (3:1 ratio). Drying concentrates flavor by removing water (herbs are 80-90% water). However, some volatile oils evaporate during drying, which is why delicate herbs (basil, cilantro, parsley, chives) have a 4:1 ratio — they lose more flavor when dried. Robust herbs (rosemary, thyme, sage, oregano) retain flavor well when dried, using a 2:1 ratio. Add dried herbs early in cooking to rehydrate and release flavor. Add fresh herbs at the end to preserve their bright, aromatic qualities. Dried herbs lose potency after 1-3 years (ground spices faster at 6-12 months). The rub test: crush dried herbs between your fingers — if they don't smell strongly, they're past prime. Store dried herbs in airtight containers away from heat and light.