This is my first time brewing and I didn't know that I had to take an initial reading prior to fermentation. I used my own apples to make cider. Can I still get an estimate on alcohol content? I think it's about done fermenting as it's been in the bucket for a little over a week.

I took a reading and have 1.35 specific gravity, 4% potential alcohol, 8% sugar (Balling) on my hydrometer. Bucket reads 68%. The brew smells yeasty, but I did not taste.

  • 8 blg would sound about right for clear apple juice. Not for fermented one.
    – Mołot
    Oct 26, 2016 at 8:12

4 Answers 4


There is some rather complex math that can calculate an OG, but requires a hydrometer and a refractometer reading post fermentation.

Brewzor Calculator (android app) and Beersmith have these formulas.

But in your case you could estimate using an OG of 1.040 which is typical for Apple juice.


Might be a duplicate here: How to calculate alcohol without OG reading?

It appears that there is a formula using your Specific Gravity from a hydrometer and if you pick up a refractometer, a measurement from that, that you can use to calculate the ABV. Jump to section "Measurement of ABV" at Brew Your Own for the formula.

From the article:

ABV = [277.8851 - 277.4(SG) + 0.9956(Brix) + 0.00523(Brix2) + 0.000013(Brix3)] x (SG/0.79)

In this equation, Brix is the Brix reading of your refractometer and SG is the specific gravity reading from your hydrometer.

If you try this, it is important to take very careful readings. Degas the sample in a blender or by pouring it between two glasses until it does not foam. Make your reading at as close to 68 °F (20 °C) as possible. If your hydrometer is calibrated in Brix, use the longer formula I cited earlier to convert it to SG. This equation fits very well with the data points. Measure-ment of ABV can be made to within 0.3% if you are careful.


Apple average about 45 ppg, so it should be pretty easy to get a ballpark estimate of your OG.


I think your 1.35 above should be 1.035. Most of the time, my apple cider is around 1.045-1.050 SG at the start, so if you plug that into the Alcohol By Volume ABV Calculator with 1.035 as your ending, it comes out to around 1%-2% alcohol respectively. That abv seems low for cider though, as without adding sugar in mine, I consistently have 6-8% abv once the first fermentation is complete, and around 10-13% abv if I added extra sugar.

I would only rack it and consider first fermentation complete, after the airlock only produces one bubble or less per minute, instead of waiting a certain period of time like a week.

It sounds like your initial fermentation isn't complete and needs to continue (I usually leave mine 2 weeks or so, around 55-60 degrees)as the abv seems low at 2%, though there are many factors that could affect that, temp, yeast type, initial yeast pitch, etcetera.

I would suggest doing the bubble count before disturbing it. The only way I can think of that would have your initial fermentation complete, and that low of abv, is if the apples were really low sugar, or the fermentation has been stalled. But I am no expert, just know my experience thus far.

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