The Herbal Extraction Process | Medicinal Herb Store

A while ago, I wrote a blog post about why we chose to use alcohol as the solvent of choice in the production of our herbal tinctures. Today, I am going to discuss the concept of herbal extraction processes for herbal tinctures.

If you’ve ever made a pot of tea or cup of coffee, then you’ve performed an extraction. The process of extraction involves isolating one or more compounds from a mixture.

The concept of extracting the medicinal properties of a herb has been around for thousands of years, though has varied over time. It is thought that our ancestors discovered that certain plants were beneficial to their health. After being cultivated, these herbs dried out, and attempts were made to restore their succulent qualities by steeping them in water. It was by this simple act that humans discovered that by soaking plants in certain liquids, the therapeutic powers of the plant can be dissolved.

This was the beginning of a natural progression by which humans discovered that certain solvents offered superior preservative and extraction properties. Originally, water was the solvent of choice, and later, vinegar and wine began to be used. It wasn’t until the sixteenth century that the use of ethyl alcohol-based tinctures was widespread.

Some extraction processes, such as cold press extraction/maceration method, allow all the active ingredients in the plant to be extracted, whereas others, such as butane extraction isolate a single compound.

For example, allicin supplements have undergone a process by which the allicin compound has been isolated from the rest of the garlic. Likewise, curcumin supplements have undergone a process by which the curcumin compound has been isolated from the rest of the turmeric.

What happens during the extraction process:

After a plant is picked and dried, the water content that was present in the tissues of the plant evaporates. The cell walls and ducts shrink and any substance that was held by the water crystalises or dries. If this dehydrated plant matter is then placed in water or alcohol (known as the solvent or menstruum), this process is reversed. When the plant absorbs the solvent, its cell walls swell and break. This causes it to come into direct contact with the solvent. Any soluble materials (such as active ingredients) from inside the plant’s cells find their way into the solvent.

For plants with soft or spongy tissues, this process can happen quickly. For other plant materials that are harder, such as the roots of many plants, a longer period of time is required for the plant’s tissues to absorb enough of the solvent. With such plants, it helps to break up the plant matter into smaller pieces to expose their softer internal tissues directly to the solvent. Some plant matter, therefore, must be chopped or blended up.

The outer walls of some plant parts such as seeds or roots are designed to be water-proof, while the walls of their inner cells are more permeable. They allow the solvent to diffuse through them and dissolve the soluble contents of the plant.

The benefits of powdered herbs:

The process of passing the soluble plant contents through the plant’s cell walls can be a slow one. It can be sped up by increasing the plant’s surface area before beginning the extraction process. One way of doing this is to use a powdered herb rather than one that is chopped into bigger pieces.

Powdering a herb breaks down many of its outer surface cells and allows the solvent to come into direct contact with the contents of the cells.

To heat or not to heat?

Applying heat can also hasten this process, though this should be done gently, with a low heat.

Applying too much heat can destroy the plant’s enzymes, release desired volatile components such as essential oils, and can coagulate the plant’s proteins which can interfere with the extraction process. It can also dissolve the plant’s gums and proteins.

Tune in next week to learn about the different methods of extraction, and the positive and negatives of each process.

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