"I had heard that we weren't supposed to ingest essential oils. Is is because they can burn? How is it that it is o.k. to cook with them? You are not the only person I know that uses them for cooking, so I am perplexed. What have you learned as you have been experimenting?"
I've also read that you should never ingest essential oils, and yet seen recipes and concoctions using them. Young Living oils' company hired a chef to blog and create recipes using their essential oils, and doTERRA encourages their distributors to have websites using them.
The thought process I've gone through is:
(1) essential oils are already in the foods you normally eat.
(2) It takes a lot of one food/herb to produce the oil.
(3) The possible danger of swallowing essential oil lies in the fact that they are so strong. Caustic, even. They need diluted.
SO- as long as you can figure out how much oil is equivalent to a normal amount of food, and there aren't any traces of scary chemicals in the oil, then it should be about the same as using that food or herb. It's naturally diluted when you mix it with other ingredients.
The thing to remember, though, is that different types of foods or herbs yield different amounts of oil because some foods are more oily than others. So that's why I posted suggested amounts with a reminder that they might vary. I also experimented separately with different types of oils, i.e. citrus oils (the zest is naturally high in oil) and herbs (almost all naturally low in oils). It can't hurt, either, to find out what the oils are used for, so you know what symptoms to look for in case of 'overdose'! There are some oils more potentially problematic than others. (Nutmeg, for instance- but, then again, you can also get in trouble by using too much powdered nutmeg...)
The rough equivalents for citrus oils, according to my testing, anyway, are
1 tsp. extract = 2 Tbsp. zest = 1 c. citrus juice = 16 drops oil = 1/8 tsp. oil
Note, though, that using oil instead of juice, changes the amount of acidity in batter, so you need to adjust the leavening accordingly. For this same reason, I have not been impressed with 'lemon oil lemonade': there's no tartness to it.
For more info on using essential oils in your recipes, see Cooking With Essential Oils.