Infusion is a method of extracting soluble constituents from plant material by allowing it to steep in a liquid for a period of time.
In herbalism, the word most commonly refers to a water-based preparation made by pouring hot or boiling water over herbs, allowing them to steep, and then straining the liquid.
The term can describe both the process and the finished preparation.
How the Term is Used
An infusion is an extraction method.
The liquid acts as the solvent, moving soluble plant constituents out of the botanical material and into the finished preparation.
Leaves, flowers, and other relatively tender plant parts are commonly prepared this way because they often do not require the prolonged heating used for tougher roots and bark.
Infusion vs. Herbal Infusion
These terms overlap considerably.
Infusion describes the preparation method itself.
Herbal Infusion usually refers specifically to an infusion made from herbs or other botanical material, particularly one intended as an herbal beverage or traditional preparation.
So an herbal infusion is an infusion—but the word infusion can be used more broadly when discussing extraction methods.
See Herbal Infusion for a closer look at the familiar herb-and-water preparation.
Infusion vs. Decoction
Both are water-based herbal preparations, but they use different methods.
An Infusion steeps plant material in water, while a Decoction uses sustained heating or simmering, often for tougher plant parts. The preparation should fit the plant—not simply whichever pot happens to be handy.
See Decoction for the full explanation of that preparation method.
Hot & Cold Infusions
Not every infusion requires boiling water.
A hot infusion uses heated water and is the method most people recognize as making herbal tea.
A cold infusion allows plant material to steep in cool or room-temperature water for a longer period.
Cold-water preparations may be chosen for certain botanicals or constituents, particularly when prolonged heat is unnecessary or undesirable.
The exact method depends on the herb and what you are trying to extract.
Plant Part Matters
Different parts of the same plant can contain different concentrations and types of constituents.
Tender leaves and flowers are frequently infused.
Dense roots and bark may be better suited to decoction.
But those are guidelines—not absolute rules.
The individual botanical matters more than simply whether something happens to be a leaf, root, flower, or seed.
Time, Temperature & Covering
Infusion instructions usually specify some combination of:
amount of herb, amount of water, water temperature, and steeping time.
Those details affect the finished preparation.
EMA guidance also recommends keeping medicinal herbal infusions covered while steeping. This is particularly useful with aromatic herbs, where volatile compounds can escape with steam.
As we said on the Herbal Infusion page:
If the part you want smells wonderful and escapes with the steam…
maybe don’t let all the steam escape.
Stronger Is Not Always Better
A longer steep or larger amount of herb may extract more material—but more is not automatically better.
Increasing steeping time can also change bitterness, astringency, aroma, flavor, and the balance of compounds in the finished preparation.
That is why:
“Steep until you remember you left it on the counter”
is not particularly precise herbal instruction.
When preparation matters, follow instructions appropriate to the individual plant.
Fresh vs. Dried Herbs
Both fresh and dried plant material can be infused.
Drying changes the amount of water naturally present in the plant and may affect aroma, texture, concentration by weight, and some plant constituents.
As a result, fresh and dried herbs are not always used in identical amounts.
Same plant does not automatically mean same preparation.
Freshness & Storage
Water-based infusions are generally prepared for relatively immediate use.
EMA guidance for medicinal herbal teas recommends drinking an infusion shortly after preparation; when storage is appropriate, it advises keeping the preparation covered and refrigerated for no more than 24 hours.
Specific instructions for the botanical or preparation should take precedence.
Safety & Considerations
Infusion is a preparation method, not a safety category.
Making an herb into tea does not remove its potential contraindications, allergies, interactions, or dose considerations.
The useful questions are still:
Which plant? Which part? How much? How was it prepared?
Related Terms
Related concepts include Herbal Infusion, Decoction, Maceration, Tisane, Tincture, Glycerite and Volatile Oil. These terms all connect to botanical preparation and extraction, but they describe different methods or concepts.
How to Evaluate Infusion Instructions
When a preparation calls for an infusion, consider which botanical and plant part are being used, the amount of herb and water, temperature, steeping time, and whether the preparation should remain covered.
If research is being cited, also check whether the study actually used an infusion rather than a tincture, standardized extract, or other preparation.
Preparation is part of the information.
Why Context Matters
An infusion looks wonderfully simple:
plant + liquid + time.
But changing the plant, solvent, temperature, or steeping time can change what ends up in the finished preparation.
Understanding the method helps explain why herbalists don’t prepare every plant exactly the same way.
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 preparation terminology from marketing claims, 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.
Add the water. Give it time. Let the plant speak. 🌿💧