Firstly,
Great product, I've made about 8 batches so far over the last month, it even inspired me to start making beer again.
Secondly,
I bought a 1-gallon jug of Apple Juice that I split into 2 batches to test different sugar amounts.
1 2L (bottle was soda bottle) I added 2 cups sugar - it is fine, except extremely sweet.
The other 2l bottle (same type of soda bottle) I added 1/3C sugar. I opened it the other night and it fizzed up fine so it seemed that everything was working. I noticed that it smelled like sulfur. It tasted fine, but the smell (though not strong, certainly present) was off-putting. Was the batch infected somehow?
Thirdly,
My batches with 1 cup or more sugar are all extremely sweet. (One with 2 cups was sickly sweet after a week of fermenting) I also can't taste the alcohol in some of them (even after fermenting for over a week). They are definitely carbonated (so the yeast is working to some degree), but I would think that the more sugar does not equate to a sweeter drink (given enough fermentation time). My kitchen temp is around 70F and I am just eyeballing the amount of yeast, I estimate about 1/16th to 1/8th tsp of yeast per 2l batch. Am I underpitching the yeast? Not given enough fermentation time?