To produce a stock essence, combine 10 drops of the mother essence in a 60 mL container with a 50:50 mixture of spring water and alcohol or vinegar. To produce a dose bottle, place one drop of essence from the stock bottle in a 15-mL container filled with a 50:50 mixture of water and alcohol or vinegar. Seal and shake well to dissolve the essence into the liquid. Essence is used to create a variety of products, such as soaps, lotions, shampoos, and sprays. It can be added to these products during preparation or even included in its own right; for example, an essential oil bath adds scent to the water and can be enjoyed as a form of aromatherapy. Essential oils are the steam-distilled volatile compounds found in plants that give their products their smell. They contain a large number of chemical compounds, most notably aromatic hydrocarbons such as thymol and carvacrol found in thyme and oregano respectively, but also include other chemicals such as esters (e.g. citronellyl acetate found in citronella) and terpenes (e.g. linalool found in lavender). The quality of essential oils varies depending on several factors including species, growth conditions, and extraction methods. For example, oils extracted using organic methods will have different properties from those obtained using conventional techniques.