How do people preserve wines and champagnes for decades? Is there a special method or is it like keep in wine storage or cupboard and forget for some decades to be better in taste?
This really depends on the drink itself. Some wines are meant to keep for years. Others should be drunk immediately. Most should be drunk within 1 or 2 years. So choose your wine carefully. There are various vintage wine guides online.
That said, once you have chosen a wine meant for ageing, you do want a cellar (or if that is not available, a refrigerator designed for the purpose) that will be able to give you consistent:
- Temperature: around 12-13 C (55 F)
- Humidity: around 70 percent
- Light: keep wines out of sunlight or even bright lights
And if the bottles have cork stoppers, they need to be stored on their side to prevent the cork drying out. This isn't an issue with screw tops.
And that's pretty much it. If you don't have a cooler or cellar, keeping them in a cool, dark cupboard is still going to help...
I did a deep dive into Stack Exchange because I thought this question would've been asked before! But, it has not. That doesn't mean that the answer isn't super easy to find.
First of all, not all wines are meant to be aged. The vast majority of wines are meant to consume when you pick them up at the store. How can you tell which are which? Mainly on price (although not always the case). As the price point goes higher, these wines have been made with aging in mind and many times are unpalatable at a younger age. Red wines are meant to age longer because the tannins (the thing that gives red wine it's color) are an anti-oxidant. Some white wines like Riesling can age for decades. Champagnes can age for a long time, but because of their delicate nature and the cork and the whole CO2 pressure thing, they are harder to age. I've had some nicely aged Champagnes.
So basically, keep it in the dark and as close to freezing as possible. Some say that 55F is the best temperature, but actually the closer to freezing you get makes it keep longer. The problem is that for bottles with corks you should have a relatively high humidity so the corks don't dry out.
The myth that wines with screw caps don't age has been debunked by the Australian wine industry because the have mostly moved to screw caps and the wines age just fine if differently than bottles with corks.
Aging of Wine from Wikipedia pretty much tells you the whole story.