You can even mark the date you opened it on the top of the stopper!
Promising review: ""I love bubbles — champs, cava, prosecco, sparkling rose — they just know how to bring the party! But no one likes when sparkling wine goes flat, or you feel like you can't just have one or two glasses without ruining the whole bottle. So I went on Amazon and found the best champagne stopper I could find and immediately hit 'add to cart.' What a great purchase! This little bb is so easy to use — just pop it on top of the bottle, push the metal sides in so it clamps on, then push the top button several times to vacuum seal and preserve the bubs. Then when you next want a glass, spritz, or mimosa, you'll hear that same *POP* you heard when first taking out the cork — and the effervescence you so crave will be fully intact. Plus, you can confidently store your leftover bottle on its side in your fridge; I've had zero leakage problems with this thus far!" —Maitland Quitmeyer, BuzzFeed shopping editor (check out her full review here, #1)
Get it from Amazon for $8.97.