How do I get a higher ABV out of Birch Sap?

[Sticks n' Stones]

I should start off by saying I'm a complete green horn and have only made Birch "wine". A quick gist I think might clear up some questions relating to the dogmatic specifics of my questions. I'm something of a part-time hunter gatherer and loving making all of my own things (hunting tools, brain tanning hides, building shelters, friction fires, etc.) Being the Cro-Magnon man that I am, I'd like to try and make a harder drink than a wine (in terms of the alcohol content, and in taste more than anything, I'd like it to be up there with a liquor) that involves no grain. (I know that Black Birch sap will be my base, and I will be using berries (blue, black and raspberries), some herbs, and unpasteurized honey.

I don't know much about the inner workings of fermentation and I don't really know what I'm doing. I don't have much in the way of dedicated homebrew gear (my first bottle of birch juice was a nearly topped off Sangria bottle with a single clove and an unmeasured amount of berries) that I corked and let it sit for a couple weeks in my attic. Basically I have a lot to learn and would greatly appreciate some guidance.

Oh and for anyone wondering my Birch "wine" had a cloudy crimson to it, and had a taste similar to a Pinot Noir.

 

[gunhaus]

The seasons are little off, but freeze distillation in winter temps would boost the booze! Search freeze distillation (Jacking - as in apple jack) and you will get some good insight.

 

[mashpaddled]

The problem with trying to get into liquor strength with fermentation alone is that yeast generally lacks the ability to ferment that much sugar and survive in that high of an ABV. Distillation would be the easiest route here because it is the most effective way to reduce the water content after fermentation which concentrates and raises the ABV.

The best thing you could do is to pick a yeast strain with high alcohol tolerance, start it with a moderate sugar content and incrementally feed sugar and nutrients throughout fermentation and try to get into the very high teens or maybe into the low twenties with an especially aggressive wine strain. Depending upon your access to subzero temperatures you might be able to freeze distill your resulting wine into thirty percent ABV or higher. A regular chest freezer might add a few points of ABV but to get a big jump you would need access to temperatures below 0F.

 

[gunhaus]

The problem with trying to get into liquor strength with fermentation alone is that yeast generally lacks the ability to ferment that much sugar and survive in that high of an ABV. Distillation would be the easiest route here because it is the most effective way to reduce the water content after fermentation which concentrates and raises the ABV.

The best thing you could do is to pick a yeast strain with high alcohol tolerance, start it with a moderate sugar content and incrementally feed sugar and nutrients throughout fermentation and try to get into the very high teens or maybe into the low twenties with an especially aggressive wine strain. Depending upon your access to subzero temperatures you might be able to freeze distill your resulting wine into thirty percent ABV or higher. A regular chest freezer might add a few points of ABV but to get a big jump you would need access to temperatures below 0F.

Dry ice and a cooler brother! Dry ice and a cooler. Or a good late January night or two around my parts.

 

[philjohnwilliams]

Just to be clear, are you fermenting straight sap or sap that has been boiled down as you would with maple sap? Alcohol content is of course related to sugar concentration, so a higher ABV would require a higher sugar concentration in the liquid you are fermenting.

 

[day_trippr]

^that^
Pretty much everything else is of lesser impact...

Cheers!

 

[Sticks n' Stones]

fermenting straight sap or sap that has been boiled down as you would with maple sap?

Straight sap

 

[philjohnwilliams]

Straight sap

Ok then, to get higher ABV you will have to boil that sap down quite a bit before fermenting it. If you don't already have a hydrometer you should get one and learn how to use it. If you are new to fermenting then I would suggest starting with a lower gravity, something like 1.050. I don't know the sugar concentration of birch sap, but I assume it must be somewhat close to maple sap, if so be aware that you will have to boil off a significant amount of water to get to a high enough gravity to make a high ABV.