Acidic wine gone bad question

[wood1954]

My 2021 Marquette wine didn’t go thru MLF and the result was very acidic almost undrinkable wine.
Last year I unbottled it all and added sugar and so2. Tonight I opened a bottle and it has gone from a dark red color to a pale red almost rose color. It didn’t have any fizz so it didn’t go thru any fermentation and it smelled off and tasted harsh and just off. I bottled about 25 bottles and left 6 gallons in a carboy. The wine in the carboy is still dark red. I’m at a loss as to why the bottles went bad and the carboy looks ok. What would cause the pigment to fade away? I thought the high acid would protect the wine but maybe malic acid just doesn’t last?

 

[MiBor]

Tonight I opened a bottle and it has gone from a dark red color to a pale red almost rose color.

Is there sediment in the bottles? I've heard one of my friends mentioning a 20 year old bottle of red wine (his first batch ever) that went clear and all the pigment was at the bottom as sediment. He tasted the clear wine and said it was just like acidic water, no tannins, not much flavor, just a little fruit taste left in it. I don't recall what varietal that wine was (probably Marquette because he had a source for many years here in Michigan), but it is possible that hybrids may do that under specific circumstances.

How was the bottled wine stored (temperature, lighting, bottle position)? Did you use any additives beside SO2 (glycerin, arabinol)?

Maybe @Rice_Guy would know what could've happened in those bottles...

 

[wood1954]

Well, it turns out I didn’t look at the label, I had pulled a bottle out of the 2021 bin and after I dumped it down the drain and started removing the label I noticed it was my rose I made from Marquette saignee. I don’t think it’s ever going to be a good wine but I have a couple dozen bottles of it. With a little sugar and aeration it’s ok. I won’t waste my time doing that again.

 

[Rice_Guy]

* the pigments in grape are quite stable. They tend to turn from a red to a brown with time but do well at staying soluble. Yes a percentage can be bound when bitartrate crystals form. ,,, Small percentage!
* ALL acids will decrease with time. An acid in mixture with an alcohol will form an esther and a water molecule. The net effect is that the total acidity will decrease over years of time and the wine will taste more sweet. I have not seen any modeling to predict what the rate is if you were monitoring TA.
* marquette rose can make a good wine. The best tasting marquette / lowest northern hybrid flavor (flinty notes) I have had was with rose.

Age is an area that needs more university work. I am guessing that it is complicated/ an inconsistent soup so reproducible results are hard to produce.

 

[winechef]

Perhaps it oxidized too.

 

[Rice_Guy]

acid flavor is a balance with sweet

Perhaps it oxidized too.

The acid is magnified by tannin (astringent not the bitter type molecule) and to some extent acetaldehyde <<~>> the balance is against residual sugar and alcohol. Acetaldehyde gives a burn when swallowing. Tannin gives long notes. Acid is tasted fast and washes out fast.

All wine has some acetaldehyde, low levels add complexity.