What Is a Decoction?
A decoction is one of the oldest and most effective methods for extracting medicinal compounds from plant materials. Unlike a simple herbal tea or infusion — where you pour hot water over delicate leaves and flowers — a decoction involves simmering tougher plant parts such as roots, bark, seeds, and dried berries over low heat for an extended period. This sustained heat breaks down the dense cell walls of woody plant matter, releasing beneficial compounds that would otherwise remain locked inside.
What You'll Need
- Dried or fresh herbs: Roots, bark, seeds, or rhizomes work best
- Filtered or spring water: Avoid chlorinated tap water where possible
- A stainless steel or glass saucepan: Avoid aluminium, which can react with plant acids
- A fine mesh strainer or cheesecloth
- A glass jar or bottle for storage
- A kitchen scale for accurate measurements
Step-by-Step Instructions
- Measure your herbs. A standard ratio is 1 tablespoon (around 5–10 g) of dried plant material per 500 ml (2 cups) of water. Adjust based on your specific herb and desired strength.
- Combine herbs and cold water. Place the plant material and cold water into your saucepan together. Starting in cold water allows the extraction to begin gradually as heat rises.
- Bring to a boil. Over medium heat, bring the mixture to a rolling boil, stirring occasionally.
- Reduce heat and simmer. Once boiling, lower the heat and allow the mixture to gently simmer uncovered for 20–45 minutes depending on the herb. Dense roots like valerian or astragalus may need the full 45 minutes.
- Strain immediately. Remove from heat and pour through a fine mesh strainer into a glass jar. Press down on the plant material to extract as much liquid as possible.
- Cool before drinking. Allow to cool slightly before consuming. Many decoctions are best taken warm rather than piping hot.
How Much Water Will You Lose?
Expect to lose roughly one-third to one-half of your water volume through evaporation during simmering. If you start with 500 ml, you may end up with 250–350 ml of finished decoction. If a recipe calls for a specific final volume, always start with more water than you think you need.
Storage and Shelf Life
Freshly made decoctions should be stored in a sealed glass container in the refrigerator and consumed within 48–72 hours. Unlike tinctures (which use alcohol as a preservative), water-based decoctions are highly perishable. For longer storage, some traditional herbalists add a small amount of honey as a natural preservative, though this is not a substitute for refrigeration.
Tips for Better Results
- Chop or break apart roots and bark before simmering to increase surface area and improve extraction.
- Keep a lid nearby but leave the pot slightly open — complete coverage can cause overflow and inhibits some volatile compounds from being released.
- Never use a microwave as a substitute. Decoction relies on sustained, gentle heat, not rapid electromagnetic heating.
- Taste as you go — the decoction should deepen in colour and flavour as the simmering progresses.
The Difference Between a Decoction and an Infusion
The most important distinction is the plant material and the method. Infusions use near-boiling water poured over delicate botanicals (like chamomile flowers or peppermint leaves) and steeped for 5–15 minutes. Decoctions use prolonged simmering for tough, fibrous materials. Some preparations actually combine both: you decoct the roots first, then add delicate herbs off the heat to infuse at the end — giving you the best of both methods.