calculating starting gravity before sugar

[doomsmith]

I've been doing a bunch of wines from fruit juices and concentrates mostly. I've been out of the hobby for a while, but getting back into it now. I'd also like to start moving up to using real fruit (well mostly, sometimes a mix of real and juice/concentrate).

My question is how to figure out the starting gravity of the must? With juice/concentrate I mix those with sugar and water and dissolve/stir until I can get my preferred sg. How would I know how much sugar to add when using real fruit? I imagine that the sg of the fruit won't be readily available until it ferments/breaks down?

My plan is to make a batch of banana to get back into it (since bananas are relatively cheap). If I chop them up and throw them in a straining bag with water/sugar, how will I know how much sugar to add if I don't know the sg of just the banana?

 

[salcoco]

normally you add pectic enzyme to fruit wine wait 24 hours before pitching yeast. instead of pitching yeast make measurement with hydrometer, add sugar then yeast. if that is not good enough for you google sugar quantity of fruit and I believe there are lists out there listing sugar content of various fruit. good luck.

 

[Scooter68]

Part of the sugar content is determined by how ripe the banana is (Or any fruit for that matter) Check out articles about this.

I just googled "does sugar content actually go up as fruit ripens"

Some interesting articles. With bananas the starch in them is converted into sugar as it ripens so the actual sugar available will change.

That's why the using fully ripened fruit is best along with using a hydrometer. I noticed that you never mentioned the use of one. "Standard" contents estimates are fine but in sugar content can vary, so using pectice enzyme, time and a hydrometer is probably your most accurate way to find your answers.