and yey another question: I've put the batch in a warmer place and now the pieces of apple that were floating sunk...
Is that normal ?
Yes.
In regards to aging, akueck is correct, that the vast majority of all grape wines (more than 95%) are not meant for long aging and won't hold up for decades. And just to clarify, I think reds usually get less SO2 than whites.
One huge factor in wine aging is the storage conditions. In order for wines to last their longest, they need to be kept at cellar temps, without fluctuations and without vibration or light exposure. Except for Madeira, if you aren't able to store wines in this way, they aren't going to last for decades.
Other long lived wines include:
Rieslings - at least from the best sites/producers. The high acidity seems to promote their longevity. Some of the late harvests can survive a century.
Dessert wines - Sauternes, Tokay, and and Rieslings may all last for decades if not centuries. The high sugar content seems to act as a preservative.
Ports - Fortified and sweet. Aging for 25-40 years really brings them along, and oxidation enhances them.
Madeira - High acidity, then cooked and oxidized into indestructible nutty goodness. The oldest drinkable wines recorded. See Meadeira thread for details.
I haven't aged anything long enough to be certain with meads, but I have seen some of my melomels fade in as little as 2 years - these were not treated with SO2. I have since starting using sulfites routinely with melomels. I am attempting to see if glutathione additions help. From my reading, including Brother Adam's book, it seems like traditionals can age a long time, especially the sack strength ones.
Interestingly he kept meads in oak casks for at least 5 years. You would expect that to lead to oxidation, and in fact he describes his dry meads as being comparable to a sherry, which makes me think they must have been oxidized. That may add character to meads and make them tasty, but in most cases, I'm not looking for oxidized.
I too am curious to know how long can standard strength meads age without developing oxidized character. It is going to be fun trying to find out.
