Do play with your hydrometer. It is the winemakers easiest to use and best tool. Champagne yeast is usually a very through and quick yiest. It is probably not a bad idea to slow it down by adding sugar late. With other yeast I would add it at the start. Also, your primary may go very quickly as the champagn yeast will eat up the little sugar in the apples very fast. Be ready to move it after 2 or 3 days.
If you have removed the seeds, do as much mashing as you can. Greater yield. Use a press if you have access to one. If not you will just loose a few percent of juce. No big deal though. It will not effect quality.
Do NOT top up you carboy after moving it to secondary. When you hit that champaigne yeast with the added sugar, it is likely to have a near explosion of activing and foaming the first day or two. If you top it, you could have a real mess on your hands when it blows out through the airlock or even blows the airlock off. Leave the carboy with 1-3 to 1-4 headspace. This will not hurt anything. The CO2 coming off the fermentation will purge this very quickly.
If you do not open the carboy until it is finished fermenting it will be fine. If fact I would say leave it alone for one month after it finishes fermenting. The head space is full of CO2 is will be no problem. That will give it time for most of the sediment to settle out. (If you do get anqcious and open it to check it and the fermentation is finshed, then you must do something about the head space as it will fill with air.) After a month or so, rack it for the final clearing and at that time it is very important to top up what ever vessels you put it in. Get some gallon jugs with extra airlocks for that period. It may be fine to make wine in plastic but I would not want to store it for bulk aging in plastic.
Ray
H2s odor still lingering 45The yeast not being happy during primary fermentation (high H2S consistent with the fermentation going reductive) may have led to some cap spoilage, if it started to dry out at any time during primary...
