During those rough stretches of winter when the temperature gets to 0 and below and everyone doubles down inside their homes, we have a rare opportunity where I live in Pennsylvania to not only do a little pond ice skating but to let nature concentrate my brews through freeze distillation. Freeze distilling is in line with all of the great methods of “natural technology” where you really don’t have do anything. All the work is in making your alcoholic beverage as you usually do and letting nature do the rest.
To freeze distill place your brew outside when the temperatures are ideally 0 degrees or below for an extended amount of time. Since water has a higher freezing point than alcohol the water will turn into ice making it easy to remove, and leaving the now concentrated alcohol behind. It’s that simple. You can remove the ice by pulling it out or siphon off the liquid. Fluctuations in temperature from day to night are welcome as it can assist with alcohol draining out of the ice crystal lattice. But overall the colder the better. The harsher it is outside, the stronger your brew will become.
In this example I made cider from the overgrown apple trees surrounding our farm. I did the crushing, pressing, and fermenting as usual. For this apple-jack trial I moved it into a food-grade plastic bucket to prevent bursting while freezing.
When the fateful stretch of sub-zero temperatures fell upon us I placed the bucket outside and every day or two reached my hand in to pluck out any ice that formed. I chose this method to get a feel for the process however it did expose the cider to oxygen. An alternative method, especially for anyone who lives in an area with reliably long stretches of appropriate temperature would be using a container with a low tap to drain off the distilled liquid.
The first few removals had huge ice chunks. I removed them by punching a hole (as pictured) to assist with lifting out. The ice size decreased each time until I really wasn’t getting anymore and considered the process done, or as good as it’ll get in this weather. In total we had a ten day run of temperatures that never climbed above 10 degrees during the day but were well under 0 at night. My cider initially was in the 5% abv range and after the freeze distillation had a distinct “wine” heat to it. While we are uncertain of how much, it did in fact raise in alcohol.
Out of curiosity I held on to the first two ice chunks and thawed them indoors for a taste. The result- water with a hint of apple essence.
Enjoy this great reason to celebrate winter’s deep freeze!