A solvent is a liquid substance capable of diluting, dissolving or extracting substances without changing their chemical form or altering themselves. It is used to extract the active ingredients of a plant.

The choice of solvent depends on the person consuming it: a child, an adult, an animal, a pregnant woman, a person with alcohol problems... or the molecules they need. For example, certain plants have antibiotic properties in alcohol and immunostimulant properties in water.

Water

This is the first solvent everyone uses: it's the one you use to make an infusion, for example, so water is used for infusions, decoctions and cold macerations.

Note that water-based products have a limited shelf life: 24 to 48 hours maximum in the fridge. You will need to use another solvent to extend the shelf life.

Another important piece of information: don't use distilled water, as it has undergone a demineralisation process and is therefore completely devoid of minerals and tends to absorb the minerals present in the body. This weakens you and is counterproductive.

Use filtered water, spring water or simply tap water, which you can boil and leave at room temperature for 1 hour.

Alcohol

This is still the most interesting solvent, although in practice we are more likely to talk about an alcohol and water solvent, as it is rare to find pure alcohol on the market. Generally we find 40% alcohol = 40% alcohol and 60% water.

Alcohol has the advantage of being very effective on plants rich in alkaloids, essential oils and antiseptic or antibiotic plants.

In general, you can choose between 2 sources of alcohol:

• Vodka (between 40 and 45º): has the advantage of being cheap and having a low aroma, leaving more room for the flavour of the plant.
• Rum (up to 55º): with its higher alcohol content, rum is ideal for extracting certain molecules and making tinctures from fresh plants.

This solvent is mainly used to make alcoholic tinctures (AT).

Vinegar

Vinegar is also used to extract the active ingredients from plants. We mainly use apple cider vinegar, which has many medicinal properties that combine with those of the plants we want to use. Apple cider vinegar contains an average of 8% alcohol.

This solvent is mainly used to make vinegar tinctures (VT).

Vegetable glycerine

This is most commonly used to preserve other solvents. The glycerine must be vegetable. Its chemical name is "propan-1,2,3-triol" or "1,2,3-propanetriol".

Glycerine has a creamy, sweet consistency and therefore has an emollient effect (softens mucous membranes), a moisturising effect (protects against dehydration), an antiseptic effect, a mild laxative and is also a mild diuretic.

This solvent is mainly used to make glycerine tinctures (GT), where the solvent is water and the preservative is vegetable glycerine.

Vegetable oils

This solvent is mainly used to make oily macerates.

There are many types of vegetable oil. They are certainly less effective than alcohol for extracting plant molecules, but they have the advantage of having medicinal properties: they are more suitable for external use: compresses, ointments, balms, etc. The choice of oil depends on its medicinal properties and shelf life.

Click here to find out more about the properties of each vegetable oil.

What is the smoke point?

The smoke point is, as the name suggests, the temperature at which the oil starts to smoke. This temperature is measured in the laboratory.

Warning: heating an oil or fat above its smoke point will cause the fatty acids it contains to decompose and release harmful compounds such as polycyclic aromatic hydrocarbons (also found in cigarettes).

Example: During frying, the temperature of the oil rises.

The temperature of 180°C is crucial because this is the temperature at which the formation of trans-isomers of fatty acids (the famous "trans fats") begins.

The presence of trans fats is responsible for cardiovascular disease, is reprotoxic (can affect fertility) and promotes certain types of cancer.