AppleJack - Help me calculate alcohol and residual sugar

[Sequoiacider]

I just finished making my first batch of AppleJack (freeze concentrated Hard Apple Cider). It turned out really nice. Highly concentrated apple flavors and aromas, and quite the alcohol kick as well. I am trying to calculate my final alcohol and residual sugar percentages.

First step is to calculate the alcohol and residual sugar of the Hard Cider that I started with. I started with 3 Gallons of King Apple juice, SG of 1.060. Pitched standard Cider yeast. When gravity reached 1.010 I added Honey to add .016 points of gravity, bringing my total SG to 1.076. I then allowed fermentation to complete to 1.001. My calculations show that this means that the Hard Cider had:
Alcohol % By Volume: 9.8%
Residual Sugar: 0.4%

I then started the "Jacking" process. Freezing the Cider in my deep freezer (allowing for very cold temps), allowing partial thaw, removing ice. I repeated this process 3 times. In the end, my 3 Gallons of Hard cider turned in to 96oz (.75 Gallons) of AppleJack, for a 4:1 concentration. This allows me to calculate the "Theoretical maximum" alcohol percentage by multiplying the calculated ABV and Sugar of my starting Cider by 4:
Theoretical Maximum ABV: 39%
Theoretical Maximum Sugar: 1.6%

Of course, for it to be those amounts, the freeze concentration process would have to be of perfect efficiency, which is impossible. This is simply the maximum amount that might be possible. I figured the most accessible way to calculate the actual alcohol percentage was to find the freezing temperature of my AppleJack and use that to determine the alcohol percentage, taking into account the effect of the residual sugar on the freezing temp.

I ran into a hiccup when looking for info of alcohol percentage-freezing temperate. Many sources on the web do not specify if the amounts shown on their charts are Alcohol by Weight or Alcohol by Volume. Even worse, I found some (SpuceEeats is an example) that say they are showing Alcohol by Volume, but the values they show are definitely Alcohol by Weight. In the end, I used Alcodens software, which allows you to calculate both ABV and ABW, so you know you are getting the units you want.

I set my deep freezer to -15C as a starting point, put a small sample of my AppleJack in the freezer with a Temp Probe in the liquid and let it sit overnight to get down to temp. When I checked it the next day, the AppleJack was at -15C and was still liquid. I then made a small, .5C, adjustment to lower the freeze temp, allowed three hours to acclimate and checked it again. I repeated this until I found the freezing temp. After two days I arrived at a determined freezing Temp of -19.5C. This corresponds to a final alcohol by volume percentage of 35.6%. After accounting for the assumed residual sugars, this leaves me with:

Final Alcohol by Volume Percentage of Finished AppleJack: 34%
Final Residual Sugars: 1.6%

Does this sound right? Some of the ice that I pulled out during the jacking process I put in a glass and drank in order to test and make sure I wasn't wasting a bunch of good stuff. It was almost all water. Only the slightest color, and very little apple or alcohol taste, which leads me to believe that my process was efficient, and my calculated numbers seem to agree.

Anyone notice any problems with my logic, reasoning or math?

 

[RPh_Guy]

Start with these more accurate estimates:
Initial batch:
ABV calculation: 10.1% ABV
Dissolved solids: 3.8%

Source: FermCalc

Theoretical maximums:
40.4% ABV
15.2% solids

 

[Sequoiacider]

I used the Alcohol/Gravity calculators on Homebrewsupply and Brewers Friend, which both gave me 9.84%. Any idea why Fermcalc gives different results for the same input? Since that part is just getting the theoretical maximum as opposed to the actual, it is less important though.

3.8% dissolved solids in the starting cider and up to 15.2% in the finished AppleJack? That doesn't sounds like it could be correct. Wouldn't dissolved solids at levels that high result in an opaque liquid? The cider was very well clarified when I started the jacking process and the finished AppleJack is also clear enough to read through it. Or am I misunderstanding the effects of dissolved solids?

What would the dissolved solids consist of? I doubt it is all residual sugar, as the AppleJack is not sweet at all.

 

[RPh_Guy]

Any idea why Fermcalc gives different results for the same input?

Different modeling equations. For example if you switch Brewers Friend to the "alternate equation", it gives 10.3%.

These are estimates, not hard scientific figures. I used the median result from the equations on FermCalc (range 9.9%-10.3%) to arrive at 10.1%.

Wouldn't dissolved solids at levels that high result in an opaque liquid?

No. For example a 70% sugar solution is perfectly clear.

What would the dissolved solids consist of? I doubt it is all residual sugar, as the AppleJack is not sweet at all.

Mostly sorbitol, probably some unfermented sucrose/fructose/dextrose, and malic acid.
Also trace amounts of aromatic compounds, tannins, glycerol, other acids (e.g. succinic, ascorbic), minerals, etc.

The alcohol and acidity reduce perceived sweetness, same as any "dry" cider.

Cheers

 

[Sequoiacider]

Thank you very much for the info, that makes a lot of sense.

So to bring it all together: With the freezing point of -19.5C, is my estimated ABV of ~34% sound right, or does the high amount of dissolved solids mean that the actual ABV is significantly lower due to the additional effects that the dissolved solids also have on the freezing temp?

 

[RPh_Guy]

I don't know. I thought you found software that could account for both the alcohol and dissolved solids.

I don't really want to spend my time figuring that out. I would just go with the theoretical max and call it a day.

 

[TGFV]

You could also buy a proofing hydrometer ( there is a technical name for them but I can't think of it.).

Mine goes as low as 20%.

As for residual sugars, wouldn't a hydrometer for gravity check give you a rough estimate?

 

[RPh_Guy]

You could also buy a proofing hydrometer ( there is a technical name for them but I can't think of it.).

Mine goes as low as 20%.

As for residual sugars, wouldn't a hydrometer for gravity check give you a rough estimate?

A proofing hydrometer is only useful for measuring distilled products because there are no dissolved solids.

Similarly, a normal hydrometer can't accurately measure ABV with just a single reading like this because the alcohol and dissolved solids quantities are both unknown and the have opposite effects on the reading.

 

[TGFV]

A proofing hydrometer is only useful for measuring distilled products because there are no dissolved solids.

Similarly, a normal hydrometer can't accurately measure ABV with just a single reading like this because the alcohol and dissolved solids quantities are both unknown and the have opposite effects on the reading.

Dang well there went my hypothesis. Never mind lol.

 

[Indiana Red]

Yeah, Ive done this a couple times. Fractal freezing a plain straight up cider. I just figure dthe algebra got a bit heavy to calc ABV in the finished product. I suppose ABV before and ABV after and ABV of the frozen slush left and the volume of each of those 3 behind should get you the data you need, but how to work it.... not sure.

 

[AngryTom]

Hello. Wondering if someone can help me out?

I've twice tried to make a batch of applejack and am getting the same result.

Here's what I do/what I end up with:

I make a three-gallon apple juice and brown sugar mixture, add champagne yeast, and get a 15% ABV wine/cider. (I've made about 12 batches of mead, so I'm not a pro, but I have some familiarity and experience with the home wine making process). After two weeks, it's bone dry. I then add three cinnamon sticks (1 per gallon), which I leave for about five days, then remove the cinnamon and leave the wine for another five or so days to settle. I take hydrometer readings throughout and both times have ended up with a .995 gravity. Once it's about 25 days old, I rack it into four 1-gallon jugs and freeze. After two days, I tighten the caps, turn the jugs upside down in the freezer, let the liquid separate from the ice, then open the upside-down jug over another container to collect the liquid, leaving the ice behind.

Using a tralle and proof alcometer, I test the fluid and end up with a 10% ABV liquid (I was expecting closer to 40%). The liquid is very acidic. It smells great and tastes strong, but the alcometer both times has said I have about 10% alcohol. The first batch smells like paint thinner and it has a kick, but I don't know if the kick is the acidity or the alcohol. I thought at first it might be a problem with the alcometer, but I tested the alcometer with whisky and it reads 40%, as expected. I always test at room temperature (70F/20C).

Anyone have any idea what's going on? Why am I getting a lesser reading than when I started? As I'm writing this, I'm wondering if the cinnamon has anything to do with it. Any thoughts on this would be greatly appreciated.

Thanks!

 

[RPh_Guy]

Using a tralle and proof alcometer, I test the fluid and end up with a 10% ABV liquid (I was expecting closer to 40%).

...

A proofing hydrometer is only useful for measuring distilled products because there are no dissolved solids.

 

[AngryTom]

Thanks RPh-Guy! I just sampled my first batch again and I now realize it's pretty strong. Just so I'm clear, due to the dissolved solids, a proofing hydrometer will never give an accurate reading for this type of project as described above, right? Will it work if I run the liquid through a filter? Thanks again!

 

[RPh_Guy]

a proofing hydrometer will never give an accurate reading for this type of project as described above, right?

Correct. No, a filter will not help.

 

[AngryTom]

Thanks again!

 

[Tancred the Brewer]

I generally calculate my ABV post freezing based on volume of liquid removed. Depending on your process and how much alcohol you are extracting and the purity of the ice, if you remove 3/4 of the liquid you can reasonably calculate you have ended with a 35-40% ABV drink post jacking.

 

[bwible]

Hello. Wondering if someone can help me out?
...
After two days, I tighten the caps, turn the jugs upside down in the freezer, let the liquid separate from the ice, then open the upside-down jug over another container to collect the liquid, leaving the ice behind.

Using a tralle and proof alcometer, I test the fluid and end up with a 10% ABV liquid (I was expecting closer to 40%).

You cannot possibly get 40% alcohol from a straight fermentation without some form of distillation. The most alcohol tolerant yeasts out there can only produce about 20% before they die from the alcohol they produce. To get more than that would require some form of distillation.

Distillation is simply the process of seperating water from a solution. Its commonly done by boiling and collecting the distillate which will be alcohol since alcohol has a lower boiling point than water. Eisbocks are made by freezing and removing ice from beer which is also a form of distillation, but its not nearly as efficient.

Alcohol content is determined by the amount of sugar in your solution and the amount that gets fermented into alcohol. You use a regular hydrometer, not a proof and traille hydrometer as previously stated. You take a reading before adding yeast. Write it down. Take another reading when fermentation is complete. The difference between the 2 numbers tells you how much alcohol you have and the final reading tells you how much sugar is left in your solution. There are free online calculators that will even do the math for you. Like the one at Brewers Friend.

If you had a gallon at 10% alcohol, that means 1/10th of it is alcohol. 128 ounces in a gallon divided by 10 would be about 12.8 ounes at 100% alcohol. So you would have to reduce a gallon from 128 ounces to probably about 28 to 30 ounces to get near 40%. Thats alot of freezing. And I don’t think you could even do it because it will not freeze any more once the alcohol gets to a certain percentage. Even strong Eisbocks usually don’t go more than 22 to 25 percent.

 

[RPh_Guy]

SOMEBODY didn't read the thread.

 

[pdxal]

Temperature of the azotrope (?) of alcohol, water, and solids will determine how high an ABV you can obtain. It's been a while since I looked this up, but if memory serves me right most deep freezers will get you to 25-28% alcohol.