Did you ever notice that when you find a wine you love, you'll drink it several times (much to your pleasure), and then all of a sudden on the next try it doesn't taste that good anymore?
Sometimes, you may even hate it. It seems like it radically changes, and where you would seemingly rely on that bottle as a guaranteed good choice, it can turn on you. So the question is, why does this happen?
Here are some possibilities:
1. That particular bottle is "corked"—this is a condition where the bacteria inside the cork can become active, and when in contact with the juice (while a bottle is resting on its side), can alter the wine's chemistry, often leaving a wet cardboard/wet dog/mildew wet laundry musky stank on the wine. Some people are actually not that sensitive to this smell, while others can detect it the second they pop the cork out; but, in either case, the wine can have a bitter taste and leave a lingering warmth, or "burn" on the throat. Or simply, the wine just is knocked off course and just has an unpleasant "awkwardness". This is a random occurrence and may be isolated to that one bottle in the batch. And it's quite a different experience versus just drinking a bottle of wine that simply isn't that great and never quite satisfies your palate.
A corked wine will be weird...and, well, a little smelly in a not-good-wine-smell way. (Of course, if the bottle has a screw-cap, then it can't be "Corked", so don't show off to your friends making this declaration when your bottle has inert metal that can't house bacteria!) Oh...one last thing! DON'T read this whole paragraph, and then project this new-fangled fancy word onto a bottle that has a moldy, crystalized, syrup residued, or crusty cork----this would NOT be a "corked" bottle, but simply one where there was some sort of temporary leakage or compromise. A truly "corked" bottle basically has a B.O. issue!
2. Your palate changes depending on what you ATE that day. Seriously, the meal you had five minutes ago, or for breakfast, can set up different flavors on your palate that interact differently with the wine that day.
3. Your palate changes based on the WEATHER outside!! Your taste buds, body chemistry, and MOOD changes when it's either 95 degrees and muggy, or crisp & chilly, or snowing outside.
4. THE MOON CHANGES YOUR WINE. I am so not joking! It is widely believed that the lunar phases provide different gravitational pulls on plant cells & molecules, and that the sugars & acids inside grape juice will literally settle in the glass into different layers depending on the gravity pull and their densities. So if you drink your favorite bottle during different weeks, it literally may be altered! This is the same concept that drives many farmers (grape or otherwise) to harvest the fruit on specific days when the moon phase "enhances" the acid-sugar complex within the grape-skin, even before it hits your glass! While there is no hard "proof", there is a good deal of evidence. Biodynamic farming specifically and diligently uses lunar & celestial tracking throughout the agricultural process.
5. THE COMPANY YOU KEEP changes your wine—again, think body chemistry meets psychology. When you're laughing along with a gregarious group, or with a Debbie Downer, your wine will be perceived and remembered differently.
6. WHERE YOU DRINK is so significant–notice when you are actually at The Amalfi Coast, your pizza never tasted so good, an ordinary olive seems magical, and that glass of wine in your hand is the best thing you ever had! Ever visited Napa or Sonoma? Seems like each wine gets better than the last, but could very well have been the same bottle you only mildly enjoyed some random weekend long ago in your hometown.
Is it your mood, or does the AIR around you and the MATCHING LOCAL FOOD pair with and ENHANCE the chemistry of the grapes?
The old phrase, "What Grows Together, Goes Together" is so true! Air, soil, sun, wind, moon, & technique all matches when food and wine are from the same origin.
So if your favorite wine is not tasting like its usual self, try it again another time; it probably still is your favorite wine, but is just going "through a phase", or waiting for you to get out of YOURS!