Examples

Herbs or other plants can be placed in boiling water for a few minutes, then discarded, and the water drunk as a beverage. A common example is tea. Many other drinks, often called ''herbal teas'' although they may contain no tealeaves, are prepared in this way. Lemon, chamomile, senna, apple, ginger, and a great many other plants are used individually or in combination. Infusion of this type are sometimes drunk for pleasure; others are claimed to be advantageous for health.

Herbal remedies and essential oils are prepared with 1 to 2 teaspoons of dried herb, or 2 to 4 fresh herbs, or flowers or berries, infused in oil or water (which does not need to be boiled) for about ten minutes and strained. Waiting too long before straining results in a bitter-tasting infusion. The herb/botanical is then removed from the oil and the oil is used in the many formulas that call for short-term infused oils.

Plants with desirable flavours may be steeped in an edible oil or vinegar for an extended period; the infused oil or vinegar is often sold still containing the plant, and is then used as flavouring. Chillies, lemon, garlic, and many other plants may be used. There can be ambiguity: for example, what is described as sesame oil may be oil extracted from sesame seeds, or an inferior quality vegetable oil infused with sesame.

The first recorded use of essential oils was in the 10th century by the Persian chemist Avicenna.