LEVO is a unique and innovative appliance for infusing herbs and botanicals into a wide range of cooking oils. However, you may be interested in using LEVO to infuse botanicals into solvents other than cooking oil, namely vegetable glycerin (VG) and food grade ethanol. VG is the main ingredient in electronic cigarette (vape) "e" juice, while ethanol is the solvent used for tincture preparation. These solvents will respond to heating and stirring in the same manner as higher boiling point cooking oils. Here you'll find advice on how to choose & utilize these methods as well as the limitations and safety considerations of doing so.
Let's start with a quick discussion of the physical properties of these two solvents, namely viscosity and boiling point:
Viscosity is the resistance to flow: for example, honey on a spoon will take longer to drip than olive oil. VG is a relatively viscous liquid at room temperature, with a consistency somewhere between coconut oil and olive oil, where as ethanol has a viscosity similar to water. We mention this to make end users aware that working with VG at room temperature might be a little tricky (and messy). By contrast, measuring, transferring, and draining ethanol from your LEVO should be just as easy as using most cooking oils. A recent bench test of LEVO with VG showed that the viscosity of VG decreased with increasing temperature. Our test used 20 grams of Grapefruit zest and 400 ml of VG. After heating to 200 oF and 1 hour of infusion time the resulting infused heated VG flowed easily from the system. This should also be the case for VG at 150 oF. Lowering the temperature will increase the viscosity of the VG until it thickens up again at room temperature.
Boiling point is the temperature at which a liquid turns into a gas as heat or energy is applied to the system. Once the boiling point is reached the temperature of the liquid will remain constant as the heat added to the system is transferred to molecules transitioning from the liquid to gas phase. Once all of the liquid is evaporated the temperature in a closed system will then continue to increase. (Think boiling spaghetti in water versus cooking with heated steam in a pressure cooker). The boiling point of VG is 360 oF (182 oC), this is well above the 200 oF maximum LEVO temperature setting. So in other words, no special considerations are required when infusing vegetable glycerin with your LEVO. Ethanol, such as 190 proof (95%) grain alcohol, on the other hand, has a boiling point of 172.9 oF (78.3 oC) at sea level. Using this solvent for tincture preparation requires a little more care and forethought.
Since the LEVO unit can be set to a temperature higher than the boiling point of grain alcohol, certain safety considerations must be taken. For example, pure ethanol is a flammable liquid, and therefore, ethanol vapor is a flammable gas. Set up your LEVO away from gas burners, do not use lighters (or in my case, Bunsen burners) near your LEVO. Even an electric stovetop can heat up to 500 oF, so please keep this in mind. For an additional level of safety, perform your infusion in a well-ventilated area: a nice breeze through an open window or a kitchen ventilation fan can keep your work area fume-free and avoid a potential fire hazard. Even with all of these safeguards the most prudent thing to do is to make sure that your ethanol DOES NOT BOIL! I am sure there are some very talented chefs out there that can flambé desserts, but I would wager they are not using a full pint of alcohol to do so.
We recommend LEVO's temperature setting at least 10 oF below the boiling point. It should be noted that a lower temperature setting will still cause evaporation, but not as quickly and not to such a degree that would be problematic during your infusion period. You may have noticed that when I referenced the boiling point of ethanol I said "at sea level" this is because volatile solvents boil at a lower temperature at higher elevations. Planning on taking your LEVO with you on your next trip to Nepal? I know I would! The LEVO is so compact that you won't even need to hire a Sherpa. (*wait for laughter/applause). I have put together a short table that lists out a few cities, their elevations and the resulting boiling points for both water and ethanol, please see below.
Table 1: Boiling Point of Water and Ethanol (200 proof) At Various Locations and Elevations(1)
*Temperature extrapolated from tabular reference data
How about some more science? For those you that might have had the opportunity to read my previous blog "Culinary Cannabis: What to Expect From Your Flower in the Kitchen" you will know that I love including pictures of molecules. So BEHOLD! Here are "ball" diagrams for Glycerin and Ethanol.
Once again, it has been a pleasure writing for the LEVO blog! I hope you have found it interesting, informative and with regards to using your LEVO safely, has given you some food for thought!
About the Author:
John Darius Soltes is a professional chemist with over 15 years of experience in both environmental science and analytical laboratory chemistry. Over the past year he has focused his attention on cannabis extracts and terpene chemistry and currently works in the Denver metropolitan area.