Decoction is a traditional method of preparing herbs by simmering plant material in water and then straining the liquid.
The method is especially useful for extracting water-soluble constituents from dense, tough plant materials such as roots, rhizomes, bark and some seeds. The word decoction can refer to both the preparation method and the finished liquid.
The World Health Organization describes a decoction as a water-based herbal preparation made by boiling herbal materials with water.
How the Term is Used
In herbalism, to decoct means to prepare plant material using sustained heat in water.
You may encounter instructions such as:
“Prepare as a decoction.”
That tells you something important. Instead of simply pouring hot water over the herb and allowing it to steep, the plant material remains in heated water for a longer period.
Unlike a quick cup of herbal tea made by pouring hot water over plant material, a decoction generally remains in contact with heated water for a longer period.
This can be particularly useful for tougher plant structures that water does not penetrate as quickly.
Why Use a Decoction?
Not all plant material is suitable to be simmered. Tender leaves and flowers are relatively easy for hot water to penetrate. Dense roots, woody stems and bark can require more time and sustained heat.
A decoction provides more heat and extraction time.
Common examples of plant materials that may be decocted include ginger rhizome, cinnamon bark, licorice root and dandelion root.
That does not mean every root or bark should automatically be decocted. The appropriate preparation still depends on the individual plant and the constituents you are trying to extract.
Decoction vs. Infusion
Both use water, but the methods are different.
Infusion = steep
Decoction = simmer
An infusion generally involves pouring hot or boiling water over plant material and allowing it to steep.
A decoction typically starts with the herb in water, brings it to a boil, and then maintains a gentle simmer for a specified period. EMA preparation guidance distinguishes these methods and notes that preparation instructions matter because the method can affect the finished herbal preparation.
What About Aromatic Herbs?
Not every plant benefits from prolonged heating.
Aromatic herbs often contain volatile compounds responsible for their characteristic fragrance. Extended boiling can allow some of those compounds to escape with the steam.
That is one reason delicate aromatic leaves and flowers are often infused rather than decocted.
In a blend containing both dense roots and aromatic herbs, the tougher ingredients may be decocted first and the aromatic herbs added toward the end. EMA guidance specifically recognizes this type of combined preparation.
Basically, if your plant smells wonderful and all that wonderful smell is leaving with the steam… you may want to rethink how long you’re boiling it.
Decoction vs. Maceration
A decoction uses sustained heat.
A maceration relies primarily on soaking plant material in a liquid for a period of time.
WHO describes water maceration as soaking herbal material at room temperature for a defined period, while decoction involves boiling the material in water.
Neither method is automatically “better.”
The preparation should fit the plant.
Preparation Matters
A decoction is not simply stronger herbal tea.
The finished preparation can be affected by the plant and plant part, the amount of herb and water used, particle size, temperature, simmering time, evaporation, and whether the pot is covered.
WHO guidance specifically notes that the amount of herbal material, amount of solvent, and length of decoction should be specified.
So:
“Boil some herbs for a while”
isn’t particularly useful preparation advice.
Freshness & Storage
Water-based herbal preparations do not have the preservative qualities of alcohol-based tinctures or some other extracts.
EMA guidance for herbal medicinal teas recommends using a decoction shortly after preparation; when applicable under those instructions, a prepared decoction may be stored covered in the refrigerator for no more than 24 hours.
Specific storage instructions for the botanical or preparation should take precedence.
Safety & Considerations
Decoction is a preparation method—not a safety guarantee.
Heating an herb does not automatically remove its contraindications, interactions, or naturally occurring compounds.
The important questions remain:
Which plant? Which plant part? How much? How concentrated? How is it intended to be used?
Related Terms
Related concepts include Infusion, Maceration, Tisane, Tincture and Bioavailability. These terms all relate to preparing or understanding botanical products, but they describe different methods or concepts.
How to Evaluate Decoction Instructions
When a botanical calls for decoction, look for more information than simply “simmer the herb.”
Consider which plant part is being used, the herb-to-water ratio, how long it should simmer, whether the plant contains important volatile constituents, and whether the instructions come from a traditional preparation, herbal monograph or specific research method.
Preparation is part of the information—not an afterthought.
Why Context Matters
A decoction may look like nothing more complicated than herbs simmering in a pot, but an extraction is taking place.
Water, heat, time and plant material all help determine what ends up in the finished preparation.
Traditional herbal practices developed different preparation methods because different plants behave differently.
Modern extraction science helps us understand why.
A Note on Wellness Language
Wellness terms can change over time and may be used differently across scientific, traditional and commercial settings. Our goal is to explain them clearly, distinguish historical meaning from modern marketing, and give enough context for you to make sense of the language you encounter.
Explore Related Terms
Continue through the Herbal & Wellness Glossary to explore related herbal actions, preparation methods and wellness concepts.
A Note on Educational Information
The information in this glossary is provided for educational purposes only. It is intended to explain terminology and provide context, not to diagnose, treat, cure or prevent disease, or replace advice from a qualified healthcare professional.
Return to the Herbal & Wellness Glossary
Return to the Herbal & Wellness Glossary to explore more terms, preparation methods and wellness concepts used throughout the site.
Know the plant. Choose the preparation. Respect the process. 🌿