Cryoconcentration is harvesting the fruits late in season and pressing the fresh juice which is left to freeze. Cryoextraction is a traditional method similar to the one used to produce ice wine. Apples are left on the trees until the end of January. In either method, the concentrated (but non-fermented) cider is higher in sugar and in apple taste than 'regular' cider. This is in contrast with beer world, where Eisbock and similar styles are created by freezing fermented beer.
I'm going with a variation on cryoextraction. I bought five gallons of frozen cider from Minea Farms in Redmond. They typically have five or six varieties of cider, in a mix of fresh and frozen. I got two gallons of Golden Russet, two gallons of Pink Lady and one gallon of Honey Crisp.The idea is that the sugary part of the cider will thaw faster than the watery part, so I can drain concentrated cider from the partially frozen gallon jugs.
What I hope to end up with is more or less Cidre de Glace: "Drinks produced by the fermentation of apple juice, which must have a concentration of sugar before fermentation made solely by the natural cold of at least 30 Brix and whose product has a residual sugar content of at least 130 grams per liter. Finally, the alcohol will be obtained over 7% and less than 13% alcohol by volume." The problems with making authentic Cidre de Glace is that I need my own orchard and cider press. And I can't cheat by adding apple juice concentrate... which I will probably need to do to get to my desired OG.
Time for some brew math. 30 Brix is approximately 1.130OG. Apple juice is typically somewhere in the neighborhood of 12.6 Brix or about 1.051OG. You can calculate Brix from the grams of sugar. 1 gr per 100 ml is one Brix. To get from 12.6 to 30, I need to concentrate each gallon to .42 gallon. And that's just the bottom end of the range, which will yield two gallons of ice cider from my five gallons of regular cider. If I collect all the sugar from one gallon into 1/3 gallon, I'll come in at around 37 Brix for just over 1 1/2 gallons of ice cider. But I know I'll never be able to get all the sugar as long as I leave some of the ice behind. I'm beginning to understand why Cidre de Glace is expensive.
Here's my high-tech cryoconcentration apple cider apparatus:
I took some scraps of wood to build a rack that holds the gallons of frozen cider upside down. The openings of the sanitized juice bottles below are slightly larger that the openings of the cider jugs, so they catch everything that drips out. Now I just need to monitor them to make sure I don't let the cider melt for too long.
I was expecting that I might need to back-fill with frozen apple cider concentrate. This would clearly be cheating in the Cidre de Glace world, but I won't be selling it so things should work out just fine. What I wasn't expecting is how much frozen apple cider I would need.
If you recall that the Brix of cider should be 12.6 or higher, my extracted cider came in at about 25 Brix, so I had just about doubled the gravity. The problem is that I need to be at 30 Brix for Ice Cider. I'll need to add enough frozen apple cider concentrate to bring it up to 30. To do that I'm going to need 72 ounces, or six cans:
72oz @ 44 Brix = 3168 200oz @ 25 Brix = 5000 ------ ------- 272oz @ 30 Brix = 8168