sour/yeasty taste after primary fermentation

[Jack_humber]

heres what i did:
i bought 3 kilos of organic fancy black grape, i mashed them and put them in a 5-liter bottle with an airlock
i didn't use any water or yeast or sugar just mashed grape.
after 7 days or so it stopped bubbling
it smells alright but the taste was very dry and sour almost undrinkable.
i took a sample and tried to lit it on fire to see if there's alcohol but nothing happened!
"please dont laugh xD"
will it get better after secondary fermentation? or should i just back sweeten it
im kinda scared to drink it

 

[NorCal]

A nice wine is all about balance. I assume you have a non-wine grape with really low pH (high acidity). It will ferment, it will make alcohol, but around 10-15% (not enough to light on fire; 40%). The good thing about wine is that there are very few things that will live in the acidic/alcohol solution that can harm you. I would add 50 ppm SO2 and let it sit for 3 months. After the 3 months rack, taste and then go from there. Chances are you will need to backsweeten a little to counter the low pH, to make it enjoyable.

 

[Jack_humber]

A nice wine is all about balance. I assume you have a non-wine grape with really low pH (high acidity). It will ferment, it will make alcohol, but around 10-15% (not enough to light on fire; 40%). The good thing about wine is that there are very few things that will live in the acidic/alcohol solution that can harm you. I would add 50 ppm SO2 and let it sit for 3 months. After the 3 months rack, taste and then go from there. Chances are you will need to backsweeten a little to counter the low pH, to make it enjoyable.

i didnt know this, thank you!