This sounds odd to me. You use ascorbic acid on fresh-cut apples to prevent them from browning. Why would it cause the cider to brown?
I'm not sure why either of these would cause spoilage flavors, either.
Does sound odd.
The anti-oxidant protection that acid provides to apples and potatoes as they are sitting on the counter is a different matter than what happens to citric or ascorbic in wine long-term. And the long term mechanism is a bit different for both.
Citric acid has been specifically found to cause spoilage in the long term storage of wine. This is particularly the case where citric acid continues to be metabolized by malolactic fermentation in wines which have that have MLF (intended or otherwise) ... MLF doesn’t just act on malic acid but on citric as well. This is also why, particularly for wines intended to be held for the long haul, any intended or induced MLF has to be followed up with *very* prompt control with SO2 ... or if one is so inclined, Lysosome (pretty expensive stuff though). The longer one waits, the more byproducts of the metabolization enter the wine.
When Ascorbic Acid is oxidized, it produces hydrogen peroxide (H2O2)... an even quicker oxidizer than O2.
However ... Hydrogen peroxide will react with any SO2 (actually, any “free” SO2) ... and will become a stable compound (namely, sulphuric acid) thereby halting some of the oxidative effects.
Bottom line ... use adequate metabisulfite additions when ascorbic acid is present.
But how many of us use K-meta or somesuch in our cider?? And so ... I suggest avoiding apple products which include ascorbic acid.
Further, ascorbic acid is also suspected as contributor to other long-term oxidization as well, and while there is less anecdotal evidence, the laboratory evidence indicates that it does promote this long-period oxidization ... and so, some winemakers are avoiding it’s use.
Now, to be sure, ascorbic acid IS used in the wine industry as a short-term anti-oxidant (it has the ability to rapidly remove oxygen from juice and wine) however, like I say later on during longer term storage it appears to act as a pro-oxidant. It appears that this is because on the backside, so to speak, of the oxidation of AA (technically what is happening), there are compounds produced that further oxidize wine.
After all this ... I’d say that the issues of these acids are much more an issue for apple wine than apple cider because usually most folks don’t hold cider long term after they make it ... though for those that do, it could be an issue.
But for mostly ... as seems to happen to much of our inventory ... “truly good and truly gone”
<sigh>.
I do still use citric acid myself to “brighten” the flavor of wine if it’s a bit flabby.
But when possible I avoid it in things I think I’m going to hold. The fact that I make very, very little grape wine also allows me to be more nonchalant about the whole thing.
Regarding that post where I suggest to avoid it, it is really not that it is so wildly critical to making a passable cider ... but with the idea of trying save myself grief and adhere to *better practices* ... I try to avoid ascorbic when I can ... though not at "any price" ... when I’m looking for a really cheap batch of cider or wine that I intend to drink promptly ... the frozen concentrated apple juice I buy is about $1.25 a 12oz frozen can ... it does contain ascorbic acid ... though many other brands do not.