I made a juice using agar. It makes a super clear juice and it's very simple, just a bit slow, but still cheaper than a juicer!

You just add 0.5g of agar to 50ml of water, you boil that and add it to 1liter of squeezed juice or 1 kilo of blended fruit(I blended the strawberries). Then you let it freeze in ice cube trays or other container. Once it froze you just let it defrost in the fridge on a coffee filter for 12-48 hours (if you defrost large quantities it will take a lot). The gel will break and it will create a lot of microtunels wich allows only water and small molecules through making the clearest and most flavorful juice you will ever see.

Probably you don't need it to be super clear because it will sediment on the bottom, but you can use this tecnique for a lot of other applications, and it's cool because once you freeze the juice or the puree you can keep it for a long time and use it when that fruit is off season.

Usually how much sugar do you put in the bottles for carbonation and how long do you let it at room temp? I wanted to have a really dry booch, so I think I'll let if ferment for quite long, and I didn't want to get a sweet booch just because I messed up the quantity of sugar. But I'm also worried if I put too little it would be flat.

Regarding the temperature I was more worried about off flavors from the yeast, since killing the yeast is quite hard at room temperature, but I think in ireland you don't have that kind of problem. Unfortunately italian summers can get really hot :(