I think it's highly doubtful that it would build enough pressure to blow up.
It would either push the fruit through or knock out the tube before that glass gives way.
Even if fruit gets in the tube,it's not going to make an airtight seal.
To sweeten it,you just have to let it build enough pressure,then pasteurize it.
And I have tried it,good stuff. No idea about the recipe though.
I just love the bottles.
I can't see why it would make a difference beyond aesthetics if it was going to be stored in a dark place while aging. All the green bottles do is block a bit more light.
I've thought stuff was clear before,and still had lees form at the bottom. I could read through it,so I thought it was done....what little did I know.
And if it's like the amount in my bottles,I'd think not. Not as visually appealing,but oh well.
The campden isn't really necessary,so that's not the issue.
Did you add the alcohol at the beginning of the fermentation? If you want to fortify it with stronger spirits,do that before bottling,after fermentation.
Maybe you killed the yeast off with the spirits...
Well,for one,make sure everyone else has clean feet xD
You'll need to campden the snot out of it probably,but I don't see any other giant issues. Maybe find out what kind of grapes they are?
Yes,it is needed. The urea is there for the nitrogen and ammonia. If it makes you feel better,it's everywhere. In your water,ground,hair conditioner,soap,fire extinguishers,skin creams,etc. Also,it's made in factories/labs,not from pee xD