A muselet is the little wire cage thingy which holds the cork into a bottle of fizzy (and usually alcoholic) liquid. I know this because my lovely husband told me, adding, "Did you know there was a word for that?"
My reply was, "Yes, love, I did. There's a word for everything. Do you not read my blog?"
He then suggested he remove the muselet from a bottle he'd previously put in the fridge, so that was OK. (The photo shows more than one night's 'research' – honest!)
Talking of liquid, for those who've not yet read my small taster collection of short stories, Not A Drop To Drink, it's still available as a free download.