Herbal Decoction Ratio Calculator
Calculate water-to-herb ratio and simmer time for herbal decoctions.
Standard 1:8 ratio for roots, barks, and tough plant material with traditional methods.
Decoction is for the tough stuff — roots, barks, and woody plant material. Anything you cannot reasonably steep with hot water alone needs simmering to break down cell walls and extract constituents. Astragalus, dandelion root, burdock, ginger root, willow bark, marshmallow root: these are decoction territory. Leaves and flowers are usually infusions, not decoctions.
The standard ratio is 1:8 by weight, dried herb to water. That means 1 ounce (28 g) of dried root needs 8 ounces (240 ml) of water to start. After simmering, you lose 30-50% of the water to evaporation, so finished volume is closer to 4-5 ounces. For a 1-cup serving, start with 1.5 cups of water.
Simmer time depends on the material.
- Soft roots (dandelion, burdock): 15-20 minutes
- Medium-firm roots (ginger, turmeric): 20-30 minutes
- Tough roots (astragalus, codonopsis): 30-45 minutes
- Hard barks (willow, slippery elm): 20-30 minutes
- Woody material (cinnamon sticks, oak bark): 30-60 minutes
Always cover the pot during simmer. Volatile compounds (including the ones doing real work) evaporate fast in an uncovered pan.
Cold-start matters. Add the herb to cold water, then bring to a low simmer. Throwing dried root into already-boiling water shocks the cells and seals some constituents inside. The cold-start gives time for water to penetrate the material before heat fully kicks in.
Strength variations.
- Standard: 1:8 ratio, 20-30 min simmer
- Strong (medicinal dose): 1:4 ratio, 30-45 min simmer
- Concentrated (decoction syrup base): 1:2 ratio, simmered to half, then reduced further
Storage. A finished decoction in the fridge keeps 48-72 hours. Add a teaspoon of brandy per cup for a week of life. For longer storage, decant into a sterilized bottle while still hot — that gives a couple weeks. For months of shelf life, turn the decoction into a syrup with honey or sugar.
Worked example. 30 g of astragalus root for a 4-day supply.
- Water at 1:8 = 240 ml
- Simmer 30 minutes covered
- Strain, expect ~150 ml finished decoction
- 4 daily doses of ~38 ml each — typical immune-tonic dose