Madeira yes. Port no.
Even Madeira fades if left open for a while.
I’ve had a bottle of 1834 Barbeito Madeira Malvazia open for 5 months with no change. Roy Hersh will tell you stories about being blind tasted on a bottle (by Manny Berk) that had been open for NINE YEARS…
How fast does vintage Port fade?
I once asked Roy Hersh how long a bottle of vintage Port lasts once opened. His response was that he had never seen one last overnight. I was quite surprised, as I figured Port was sturdy enough to last a few day’s. Roy’s response to that was he had never been in a position to find out – an open bottle gets consumed. 
Port producers will tell you that a VP should be consumed the same day it’s opened. I find that they (younger ones, at least) tend to hold nicely for two days, and then start to deteriorate after that. YMMV.
2 coravin qs.
What is the size of the needle/hole in the capsule? Is it like a thumbtack would make? Bigger/smaller?
I havent seen anyone talk about champagne. Is it any different for sparkling wines?
thanks
alan
Alan, it looks like the size of a thumbtack…don’t know about Champagne?
Was wondering how my last bottle of '96 Latour Corton Charlie was holding up…now I know…very well…liquid stones with a hint of pear. Nice way to start a Friday night!
Cannot use it on sparklers.
For Champagne, you need a Champagne tap, which is OK for shorter term use (a day or two) on bottles that don’t have crowns
Since they have to be decanted, I’ve rarely seen an aged example be nearly as good on the second day. Maybe if you immediately poured it back into the bottle and recorked, day 2 would be more feasible, but I doubt you’d get it beyond that most times. Young ones (not decanted) tend to last a couple of days without a problem, but I never think they’re as good later as they were on the first night. I almost never drink them young anyway.
I drank a 07 Dow for almost a month…it was fantastic till the end!
Fascinating… why aren’t these devices made anymore? It seems only antiques are available.
I didn’t even think of that, the coravin is great for enjoying a single glass of dessert wine without committing to the bottle. Awesome.
Actually, this is wrong. Madeira that has been in bottle for a long time often needs extended air, meaning weeks or more, for the bottle funk to blow off. At a dinner with Manny from Rare Wine Co a few years ago, he related a story about putting a half drank bottle of very old Madeira back in the cellar and losing it for 10 years or so. He said it was as good as ever when it was found and then served. Madeira is pretty much immortal. The only real question is will it actually improve or not morph into something worse over say 500 or a 1000 years. I have had Madeira from the early 19th century that would suggest it will be good almost forever, or at least a few hundred more years anyway assuming there isn’t some sort of cliff it hits at an undetermined but very old age.
I guess I have just had crappy Madeira.
Dunno, but it’s an interesting question. I’m thinking of drinking half of something like a 5 year old Broadbent and then losing it for a year or more in the the cellar to see what happens.
Maybe, I can confirm it’s impossible to kill Madeira.
I’ve had several vinage Madeiras that have been just as good after being open for several months to over a year.
I’ve had two Madeiras, New York Malmsley and Broadbent Rainwater. The first was open for months with no noticeable change; the second (not as interesting a bottling, but still) has been open so far about three weeks with no change.