I would personally love to say that all wine tastes good, but that is not always the case. Sometimes due to different reasons, wine can simply taste bad. :(
I am going to present to you the reasons why wine can taste bad, and what are the bad tastes in wine.
BAD TASTES IN WINE OR WINE FAULTS
Corked wine = cork taint = corked. This does not mean that there are pieces of cork in the wine. Corked wine has a taste of wet newspaper, wet cardboard. You know when you forget your newspaper on the balcony, and it has been raining for days, and then on a sunny Sunday you decide to clean up, and it stinks. Well, that is corked wine. The wine will have minimal fruit flavors left, and the off-flavors will be dominating.
Wine gets corked when it comes in contact with the organic material called TCA = Trichloronanissole. TCA is most commonly present in the cork that is used to seal the wine bottle. TCA can also be present in oak barrels - so the wine will get TCA if it has been aged in oak barrels. Sometimes TCA can be present on the processing lines in the winery.
You can't save corked wine. If you bought the wine in a specialized wine store, just go back and return it. They would understand you and give you money back or a new bottle.
Oxidation = oxidized wine. Unwanted oxidation can happen already during harvest time. Therefore as soon the grapes are harvested from the vine, they are handled with care throughout the whole winemaking process. We will not talk about the deliberately oxidized styles of wine in this case.
Oxidation happens when the wine is overexposed to the influence of oxygen. If your wine bottle is oxidized from the moment you opened it, it means it has been ruined during bottling or mishandled during transportation.
Oxidized wine will lose in color and flavor. The color will become brownish. Flavors will be lost; we wouldn't be able to get the fresh red fruit in Pinot Noir, for example.
Oxidized wine will get strange vinegar caramelized apple character. Wine aromas will taste dull. You know like the apple that you forgot in the fruit bowl on the shelf by the window, and they get all dark/brown and they smell funny.
Sulfur = Sulfur dioxide is a natural antioxidant. Sulfur dioxide can be used as preservative and disinfectant at the various stages of the winemaking process. The main task of the sulfur dioxide is to prevent the unwanted oxidation of the grape juice. When the level of sulfur in the wine is not monitored with care, it will be detectable by the smell of burnt matches.
A winemaker can avoid using sulfur during the whole wine production method. However, still, a small level of it will be present in the wine. Sulfur is also produced by yeast during fermentation.
Brett = Brettanomyces. Brettanomyces is a yeast that could come from the winery. It can be found on winery equipment, or even on poorly cleaned barrels.
Wines affected by Brett will have an aroma of a barnyard or sweaty horse. Ash, who would like to drink wine that tastes like that. Unless you are really drunk and you don't care (ups). Well, some people like Brett affected wine. Some will say it adds a specific complexity to the wine flavor (only at low levels, of course).
Volatile acidity = VA. Volatile acidity is present in all wines. Small levels of VA are desirable. Volatile acidity will become a fault when Acetobacter creates too much acetic acid in wine. High concentrations of acetic acid will make the wine taste like vinegar.
Well, in case you are that lucky that you get a wine affected by VA and it really tastes like vinegar...why don't you use it in a salad? I mean, you can try. Or use it for cleaning. Add some water and baking soda and scrub that bathtub!
REASONS WHY WINE CAN TASTE BAD
Wrong storage conditions:
Your kitchen countertop is definitely not the right place for wine storage, or the cabinet above your stove, or the cabinet next to your dishwasher. Cupboards next to electrical appliances generate heat when they are operating. It will not be harmful in the short term, but if you keep your wine, there for a more extended period, it will harm the wine.
Temperature fluctuations. If you are keeping your wine bottles in a place (basement, outside storage unit) where the temperature is changing drastically from -1 to + 18'C, your wine will not enjoy this. Although it is almost better to keep your wine on a cooler temperature than warm temperature. The cool temperature will slow down the aging process of the wine. The warm temperature will speed up the aging process of the wine, and that might not be beneficial for a wine that is meant to be kept for 10 years and more. Make sure the temperature cannot fall under the freezing point. If wine freezes in the bottle, it may force corks out of the bottle.
Wine bottles stored horizontally. One of the biggest enemies of wine is oxygen. After bottling, wine bottles are sealed with corks to prevent the oxygen from entering the bottle and coming in contact with the wine. Therefore it is highly recommended to keep the wine bottles stored horizontally- so the wine can be in contact with the cork to keep it slightly moist. When the cork is kept in contact with the wine, it cannot dry out and let oxygen enter the bottle. You can store your wine horizontally if you are keeping the wine bottle in a place where you can provide naturally or artificially enough humidity.
Wine bottles kept on a sunny shelf. After harvesting the grapes, there is nothing good that the sun will do for the wine. Wine does not like the sun and the light. Therefore a sunny shelf in your living room will harm your wine. To be able to prevent this, some wines are bottled in darker colored wine bottles, or often wrapped in protective cellophane.
Wine bottles stored in a place with intense vibrations. Well, I hope no one is going to keep their wine in the cabinet above the washing machine... Any type of vibrations is harmful to wine with sediment. Since wine with sediment is often decanted, we do not want all of that sediment to be mixed with the wine before we will drink it.
As always Have a Winederful day! :) and take care of your wines.