I originally posted this in the cider forum, didn't generate much interest there which makes since cider is pretty specific and results in a product very different from what this technique yields.
For the uninitiated fractional freezing or jacking in brewing terms is freezing your product to a slush like consistency, and then removing the ice crystals. Since the ice crystals are mostly water and have a lower % of alcohol than the liquid part of the product this results in a stronger more flavorful product in the end. Eisbocks and applejack are the 2 most common beverages produced from this product. Ice wines are prepared similarly though the jacking occurs pre fermentation so flavor is concentrated not alcohol. Below is my original post...
So this winter I decided to try my hand at applejack. I had some success, and learned a few things in the process so knowledge being power and all I though I would share my experience.
A few things first. First its legal and allowed for discussion that question seems to always come up in the AJ threads I've looked at. Second, the % of water removed as ice will not help you calculate abv of the final product, physics just doesn't work like that you will always lose a decent amount of alcohol through ice removal. Both my batches start at about 9% abv and probably lost considerable volume (atleast 75%) I can assure everyone that neither had the kick of a 36% abv drink.
Heres a reference for the freezing points of water and ethanol solutions at varios abvs: http://www.themadscienceblog.com/2014/01/chemistry-of-beer-part-ii-freezing.html
These won't be 100% accurate because there is more in applejack than water and ethanol, but anyone claiming 50% abv in a home freezer is mistaken.
The original volume before any freezing for both batches was 1 gallon. Everything was frozen in a standard household fridge/freezer combo. I unfortunately did not get to take advantage of the incredibly cold winter as I was planning It was too warm by the time I would have actually been able to use it.
First batch
Recipe:
2 cans apple juice concentrate
1/2 gallon preservative free Cider
1/2 cup dark brown sugar
1/2 cup white sugar
pack of cote des blanc yeast
fill to volume with water
ferment 1 month
OG: 1.078
FG (before freezing): 1.014
ABV (before freezing): 8.4
I was expecting to get a rum-like contribution from the brown sugar, I did not so I kept it to just white sugar for the next batch. The OG was lower than I was shooting for, but there is unfortunately there is not a lot of data about the contribution from AJ concentrate and unfermented cider so I had to guess and I guessed wrong; the carboy was too full to add additional sugar so I rolled with what I had at that point.
Fastfoward to my first freeze cycle. The Cider at this point tasted extremely dry so I thought adding sugar in my freezing vessle (1gallon plastic jug) would be a good idea, it was not and it made quite the mess. For the uninitiated this causes extreme carbonation and foaming. I doubt its the now starving yeast eating the sugar the reaction happened instantly, but I could be wrong. On the bright side I now head enough headspace where over expansion of ice was not a concern, if you have limited headspace avoid a mess and use a second freezing vessel.
During this first batch I was initially filtering with a colander, this was a bit slow so I bought a strainer. Also I originally just dumped the ice once the liquid drained out. DO NOT DO THIS you are throwing away precious alcohol and flavor. This is where you must taste, if you get an alcohol burn and/or an enjoyable apple taste then let the ice melt a bit. Things will take longer, but you will end up with a better product with more yield at the end. I eventually figured that out about halfway through. The ice should eventually lighten in color (light yellow or even "white") which should indicate that just about everything that is recoverable has been recovered, but when in doubt taste. The less potent "bad" ice seems to accumulate around the tops and side so you can scoop some off early.
I actually found out the Ice was still pretty potent when I decided that a significant volume I was going to dump would make an ok apple slushy, got a little tipsyer than I typically like to on a work night .
Eventually I got to about the 1qt level and the liquid was still freezing it tasted much stronger, and the flavor had gone from extra dry to semi dry so I decided it was finished. I threw out (or consumed) too many goodies during my ice removal, but I still ended up with a nice fortified apple wine.
Second batch
Recipe:
4 cans apple juice concentrate
1/2 gallon preservative free Cider
1 cup white sugar
pack of cote des blanc yeast
fill to volume with water
ferment 1 month
OG: 1.106
FG (before freezing): 1.038
ABV (before freezing): 8.931
I assumed the last batch had been so low in abv because I did not add enough goodies at the beginning. Guy at the homebrew store told me the yeast could potentially finish at 12% abv, this does not seem to be the case with these ingredients, so do not expect better than 9% with this yeast. Before freezing the product was sweet but not overpowering.
Learning my lesson I took a lot more time and care in draining the Ice, I tasted everything before deciding if it was destined for the sink or needed longer to melt. I also found that a hair dryer can speed up the process early on, when you get to the half point mark though it does not seem to help. When I got a bit past the halfway mark I noticed that I could no longer seem to separate the "good" ice from the bad ice, everything tasted like something I wanted to keep.
This is where I decided to just drain everything and throw the ice without draining into a separate container. I then let it melt and started a 2nd process of ice removal. The original container was no longer freezing after this. To prevent the same issue from re-occuring in the second container I poured the initial drippings back into the original container. After awhile of doing this there was only about a cup left, I decided it was time for another alcoholic apple slushie and declared the batch complete.
The final product is viscous, extremely sweet, and packs quite the punch. I feel like this is what I was shooting for though next year I'd like to try to take advantage of winter temperatures and I'll probably use a different strain of yeast to tone down the sweetness and increase the initial abv.
Addendum: Getting your product to freeze in large crystals (but not completely solid) is prefable to a slush. This is accomplished by making sure it has adequate time at temperature. Its also the reason that a bit after the halfway mark I had trouble separating the goodies from the water, as it no longer froze in large crystals at that point.
Feel free to criticize my methods or ask for any details that I may have left wanting.
For the uninitiated fractional freezing or jacking in brewing terms is freezing your product to a slush like consistency, and then removing the ice crystals. Since the ice crystals are mostly water and have a lower % of alcohol than the liquid part of the product this results in a stronger more flavorful product in the end. Eisbocks and applejack are the 2 most common beverages produced from this product. Ice wines are prepared similarly though the jacking occurs pre fermentation so flavor is concentrated not alcohol. Below is my original post...
So this winter I decided to try my hand at applejack. I had some success, and learned a few things in the process so knowledge being power and all I though I would share my experience.
A few things first. First its legal and allowed for discussion that question seems to always come up in the AJ threads I've looked at. Second, the % of water removed as ice will not help you calculate abv of the final product, physics just doesn't work like that you will always lose a decent amount of alcohol through ice removal. Both my batches start at about 9% abv and probably lost considerable volume (atleast 75%) I can assure everyone that neither had the kick of a 36% abv drink.
Heres a reference for the freezing points of water and ethanol solutions at varios abvs: http://www.themadscienceblog.com/2014/01/chemistry-of-beer-part-ii-freezing.html
These won't be 100% accurate because there is more in applejack than water and ethanol, but anyone claiming 50% abv in a home freezer is mistaken.
The original volume before any freezing for both batches was 1 gallon. Everything was frozen in a standard household fridge/freezer combo. I unfortunately did not get to take advantage of the incredibly cold winter as I was planning It was too warm by the time I would have actually been able to use it.
First batch
Recipe:
2 cans apple juice concentrate
1/2 gallon preservative free Cider
1/2 cup dark brown sugar
1/2 cup white sugar
pack of cote des blanc yeast
fill to volume with water
ferment 1 month
OG: 1.078
FG (before freezing): 1.014
ABV (before freezing): 8.4
I was expecting to get a rum-like contribution from the brown sugar, I did not so I kept it to just white sugar for the next batch. The OG was lower than I was shooting for, but there is unfortunately there is not a lot of data about the contribution from AJ concentrate and unfermented cider so I had to guess and I guessed wrong; the carboy was too full to add additional sugar so I rolled with what I had at that point.
Fastfoward to my first freeze cycle. The Cider at this point tasted extremely dry so I thought adding sugar in my freezing vessle (1gallon plastic jug) would be a good idea, it was not and it made quite the mess. For the uninitiated this causes extreme carbonation and foaming. I doubt its the now starving yeast eating the sugar the reaction happened instantly, but I could be wrong. On the bright side I now head enough headspace where over expansion of ice was not a concern, if you have limited headspace avoid a mess and use a second freezing vessel.
During this first batch I was initially filtering with a colander, this was a bit slow so I bought a strainer. Also I originally just dumped the ice once the liquid drained out. DO NOT DO THIS you are throwing away precious alcohol and flavor. This is where you must taste, if you get an alcohol burn and/or an enjoyable apple taste then let the ice melt a bit. Things will take longer, but you will end up with a better product with more yield at the end. I eventually figured that out about halfway through. The ice should eventually lighten in color (light yellow or even "white") which should indicate that just about everything that is recoverable has been recovered, but when in doubt taste. The less potent "bad" ice seems to accumulate around the tops and side so you can scoop some off early.
I actually found out the Ice was still pretty potent when I decided that a significant volume I was going to dump would make an ok apple slushy, got a little tipsyer than I typically like to on a work night .
Eventually I got to about the 1qt level and the liquid was still freezing it tasted much stronger, and the flavor had gone from extra dry to semi dry so I decided it was finished. I threw out (or consumed) too many goodies during my ice removal, but I still ended up with a nice fortified apple wine.
Second batch
Recipe:
4 cans apple juice concentrate
1/2 gallon preservative free Cider
1 cup white sugar
pack of cote des blanc yeast
fill to volume with water
ferment 1 month
OG: 1.106
FG (before freezing): 1.038
ABV (before freezing): 8.931
I assumed the last batch had been so low in abv because I did not add enough goodies at the beginning. Guy at the homebrew store told me the yeast could potentially finish at 12% abv, this does not seem to be the case with these ingredients, so do not expect better than 9% with this yeast. Before freezing the product was sweet but not overpowering.
Learning my lesson I took a lot more time and care in draining the Ice, I tasted everything before deciding if it was destined for the sink or needed longer to melt. I also found that a hair dryer can speed up the process early on, when you get to the half point mark though it does not seem to help. When I got a bit past the halfway mark I noticed that I could no longer seem to separate the "good" ice from the bad ice, everything tasted like something I wanted to keep.
This is where I decided to just drain everything and throw the ice without draining into a separate container. I then let it melt and started a 2nd process of ice removal. The original container was no longer freezing after this. To prevent the same issue from re-occuring in the second container I poured the initial drippings back into the original container. After awhile of doing this there was only about a cup left, I decided it was time for another alcoholic apple slushie and declared the batch complete.
The final product is viscous, extremely sweet, and packs quite the punch. I feel like this is what I was shooting for though next year I'd like to try to take advantage of winter temperatures and I'll probably use a different strain of yeast to tone down the sweetness and increase the initial abv.
Addendum: Getting your product to freeze in large crystals (but not completely solid) is prefable to a slush. This is accomplished by making sure it has adequate time at temperature. Its also the reason that a bit after the halfway mark I had trouble separating the goodies from the water, as it no longer froze in large crystals at that point.
Feel free to criticize my methods or ask for any details that I may have left wanting.