About 4-5 days ago I crushed up 2lbs of grapes and added a cup of sugar and a couple sliced oranges and lemons and a thick slice of bread to a glass jug.

Covered the lid over the top with a towel and the lid on top and have been letting it sit now for around 5 days.

Today I decided to taste it. It doesn’t taste half bad.

What’s the current alcohol content would you estimate given these conditions?

I’m guessing around 5-6%

There was definitely a bit of bubbling going on in there. Nothing too crazy but bubbling

  • 1
    What kind of grape were they? Table grapes are usually around 17-19 brix. So, if we had a volume of juice we might be able to estimate the starting brix. Why did you put bread in there? All the yeast is dead in bread... Apr 12, 2020 at 16:55
  • @farmersteve bread is pretty common in many ferments (pickles, kvass, wine, &c.) as a source of nutrients for the microbes (sugars, nitrogen, vitamins). That would be my guess. Also, depending on how the bread was stored, it may indeed be harboring many environmental microbes of potential use to a (presumably) wild wine fermentation. Apr 12, 2020 at 20:43
  • @FranklinPCombs grape wine really doesn't need nutrients since grapes contain all the nutrients needed to ferment. Other fruits I can see that. IMO, I would skip the bread and just dump some bakers or wine yeast in there and let her rip. Apr 12, 2020 at 20:55
  • A slice of bread for 'yeast' and only 5 days in, PLUS it tastes good? Probably closer to 1-2%
    – rob
    Jan 11, 2021 at 14:49

1 Answer 1


Considering :

  • Fermetation usually starts after a few hours up to a full day after crushing.
  • It takes in general about 2 weeks to fully ferment (depending on variables, temperature, etc.)
  • You added one cup of sugar in a total of? 1 gallon of liquid? It will add a little % but not much.

Your guess of 5-6% is as good as any.

You can grab an hydrometer to confirm that fermentation is completed. Then, once you know the wine is dry, you can use a vinometer to mesure the alcohol content of your finished wine. Both these tools are cheap to purchase and will help you get a better idea of what you are making.

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