Everyone’s least favorite movie in a trilogy is the one that explains everything. It is a necessary evil in the grand scheme of things, but that doesn’t make it any better. However, it is essential to the understanding and full enjoyment of the trilogy.
WELCOME TO INFUSION 101’S LEAST FAVORITE POST.
Yes, Science! I learned many things as a Sciences major in college: 1) I’m kind of a nerd. 2) Diffusion. 3) Oxidation.
The basic principle governing Infusions is diffusion. I could sit here and do a full expose on Fick’s Law (see point #1 above) but this isn’t a graduate thesis. In short: things move from areas of high concentration to areas of low concentration. Ex. You’re at your local watering hole for a drink with friends and the bar is crowded as everyone tries to get that last round or twelve in before Happy Hour ends. You spot an empty corner of the room with chairs and tables galore and move to get some space. You just diffused. Now imagine you were the “flavor atoms” of an orange recently submerged in vodka. You would see all those empty chairs and tables in the vodka and go running to escape the eleventy billion other “flavor atoms” in the orange. When the orange leaves, you get to stay. Boom, Orange Vodka.
There are two main factors that can hinder diffusion when it comes to Infusing spirits.
What if there was a bouncer in the bar who was regulating the flow of people from the bar area to the open space. His name tag would say “membrane.” While most cell membranes are fairly lenient bouncers, we find some who are a bit tougher to penetrate. When this happens, we have to find a work around to make sure the “flavor atoms” are allowed to move more freely. For instance: puncturing berries when we infuse them to allow a better pathway for infusion. The biggest & baddest bouncer of them all you ask? The skin. This is why we cut fruits and veggies to create as much surface area, without skin, as possible.
Oxidation is basically diffusion that occurs at an objects meeting point with the air. Oxidation however is not a friendly process as it destroys what it interacts with in the process. If you have ever cut an apple and noticed it quickly turning from a crisp white to an off brownish color, you’ve witness Oxidation. How does this effect infusions? It not only takes away from the number of “flavor atoms” that are going into your spirit (if they go into the air, they are NOT going into your spirit) but aids in the decomposition of your ingredients, thus rendering them useless, and potentially allowing them to contaminate your infusion. How do we prevent Oxidation? Simple –> Rule #3) completely cover (submerge) your ingredients in the spirit. If there is no air to interact with your fruit, no oxidation occurs.
… and if you’re a visual learner, here is an old high school like video on diffusion.