Let's look at where essential oils come from and how they get in the little bottles you purchase. Did you know that it takes approximately 1 ton or 2,000 pounds of rose petals to get 1 pound of essential oil? That's a lot of plant material, wouldn't you agree? Have you ever purchased or looked at the price of rose essential oil? Prices vary because of many factors. However, it's not uncommon to pay $200 for 5 ml, or one teaspoon of rose essential oil. Notice here the capital EO right next to rose, that's often used in place of writing out essential oil, and you'll see that throughout this course. Also notice that the botanical name is used for rose, Rosa damascena. Since there are often different variety of plants, we always need to be sure which plant we are referring to. This is particularly important when you're using essential oils for therapeutic purpose since there are more than one species of the same plant. One example of this is lavender. True lavender that we might use for calming is Lavandula angustifolia. Another lavender species with very different chemical properties and not known for calming is Lavandula latifolia. For simplicity sake, you'll see both common and botanical names used throughout this course. The botanical name will always be used when referring to the specific therapeutic properties. And once the botanical name is identified, then most often you'll see the common name. Before we look at how we actually obtain essential oils, let's look at some plants to see where the essential oils come from. The amount of essential oils produced by different plants is quite variable. Many plants essential oils are readily extracted, while others are just too fragile to withstand this process. Still others don't produce enough essential oil to be cost-effective for steam distillation. Some plants are first dried and then distilled, and other plants are distilled while fresh. You don't need to know the specifics of each plant at this point. I just want you to know this fact and that you can readily find this type of information in numerous essential oil reference books. You recall I mentioned in the first video of this lesson that essential oils come from a variety of plant parts. I want to point out a few that you might be familiar with, you already know that rose essential oil is from the flower petals. Lavender, Lavandula angustifolia, is from the flowering tops and stocks. Frankincense, Boswellia carterii, is from the resin, think of it like a sap. Anise is from the seed, Pimpinella anisum. Basil is from the leaf. Ginger from the rhizome, grapefruit from the rind. Hmm, Cedar Wood, any idea? That's right, the wood. Steam distillation and expression are the primary ways in which we obtain essential oils. Most essential oils are obtained by steam distillation, so I'll start there. The harvested plant material is placed in a large vessel. So notice the second vessel, a heat source produces steam that is then passed through the vessel holding the plant material. This steam ruptures and loosens the essential oils from the plants, and allows the precious volatile molecules to rise to the top of that vessel with the steam. Volatile means readily vaporizes or dissipates. From there the steam and volatile essential oil molecules pass through a cold condenser. As the condenser cools the steam back into water, it moves with the essential oils to the final vessel. Here, the essential oils rise to the top. So picture how oil and water separate. The essential oils are now easily extracted from the remaining floral water, as you can see they're on top of the floral water. It's worth noting that the remaining floral water also has therapeutic properties. You may be familiar with some of these such as rose water or orange water. These floral waters are also known as aromatic water hydrosols, or hydrolats. Essential oils and citrus fruits are held in the rinds, and are typically extracted in a process unique to them known as expression or cold pressing. Although these fruit rind essential oils can be steam distilled, it's much more common to extract them with the expression method. Think of how lemon or orange squirt from the rind when you peel it, or when you zest it. That's the essential oil. Commercially produced essential oils are obtained through a mechanical process or puncturing of the rinds. This rind material is then put in a centrifuge and separated from the essential oil. No heat is used, so no chemical changes take place as might in steam distillation with a heat source. So the essential oil will smell identical to the plant, this isn't the same as when essential oils are obtained with the heat source. So the next time you open a bottle of grapefruit or lemon essential oil, notice the fruit aroma. Let's check your knowledge about essential oil extraction. At this time, the most important things to know is that essential oils are typically made through a steam distillation, or expression process. Various parts of the plant hold essential oils, and that you should describe essential oils by their botanical name to ensure you are referencing or using the right plant essential oil. This video covered several examples of essential oils to give you a visual and to show you that essential oils come from more than just flowers. Try zesting a lemon, or crushing an herbal leaf such as basil, or a flowering top, such as lavender, with your fingers to release the essential oil aroma. This will be a fun way to get you thinking more about the essential oil extraction and concentration topics we cover in the next video.