A cider I have on for the missus (my first - both cider and wife) at the moment is finishing like a very cheap white wine when tasting the FG sample - is this the malic acid taste you're talking about? Christ, I'd be stoked if someone can tell me this will go away.
10 day old cider tastes nasty :icon_vomit:
#1 Age is your friend with Cider, the longer you age it the better it gets. so don't freak out and toss your brew at week 3 or 4 when you bottle it.
2, 3, 6 or ***12*** months aging does wonders for an uninfected cider.
#2 Traditional ciders can be up to 3 months before bottling to make sure it really is cleared properly. If I had the spare demijohns or other fermenters and not in a rush, then a basic apple cider would be left alone for at least eight weeks before bottling, the best indication a cider is ready for bottling without resorting to the hydrometer is seeing that all the yeast has dropped to the bottom and the brew is absolutely crystal clear.
#3 On bottling or racking, if it tastes nasty then don't toss it. Nasty being tangy, tart, harsh, or just plain un-apple-flavoured.
Only if it tastes like vinegar, or nailpolish remover, camel vomit, etc. - you may want to consider dumping it.
#4 Always hold back part of your brews for extended aging - 9 months to well over a year or two in a bottle or two is fine. This is so you can learn how much patience makes a top notch brew.
For Cider Maturation, the malo-lactic fermentation is carried out by non-slime forming strains of Leuconostoc mesenteroides, Lactobacillus collinoides and very rarely Pediococcus cerevisiae. These bacteria are readily inhibited by the levels of sulphur dioxide used in cider making yet ciders readily undergo malo-lactic fermentation in the spring/summer after they were made. The explanation for this is not certain, possibly lab strains of these organisms are more sensitive to sulphur dioxide than are wild strains, possibly the sulphur dioxide merely inhibits the bacteria and they subsequently recover, or possibly there are other organisms at work.