Every year, for the first seder, we go to the shul's community seder. This year was no exception. I'm famous for bringing my own wine, always having a corkscrew, bringing my own cups, home-made morror and, for the past two year, sashimi. This year, unfortunately, I forgot my sashimi at home, though one of my friends brought some cured salmon, a recipe I replicated for the last two days.
We had a family in shul, they stopped coming a while back, where the wife was quiet known for her frumminess and her isms. This year, they decided to join the seder and were sitting right behind me. I overheard her asking someone else at their table to open a bottle for her because their minchag is not to open bottles. This was on Yom Tov. I just couldn't let that go. I turned around and asked her why would she say something so ridiculous as not opening bottles on Yom Tov?! She told me that they used to go to one family when they were becoming religious and that family didn't open bottles on Yom Tov and since they're following their minchagim, they also don't open bottles on Yom Tov.
I told her a story of mine about me and another guy going to a shabbaton. Our host was this psycho frummie bal teshuva who kept telling us how humble he is by become frum, even though his father's a millionaire. He spent the whole shabbat telling us about how humble he is. He also decided to educate the stupid russkies about hilchos shabbos. Apparently you're not allowed to remove a dirty plate from the table, unless you place a piece of bread on it. He was presenting this as a halocha. This is what you get when someone thinks that if he learns gemorah, he doesn't need to learn halochos. This guy, however, didn't have a minchag of eating suedat shlishi, even though it's in gemorah too.
I told the woman that the point of my story is that there are minchagim and there are personal chumras, frequently based on ignorance. A minchag is something that a lot of people do and it's generally accepted, this is quiet the opposite of a personal chumra. She told me that it is so a minchag and since their friends have followed it, they will follow it too. Incidentally, I'm pretty sure her rabbi will disagree with her on this. This quiet pissed me off and I told her that her friends don't know halocha and based their chumra on ignorance and that she doesn't know halochas either. She harrumphed and turned to her table.
Opening bottles on shabbat is a hotly contested topic with many holding that you can and many holding that you can't. Sephardim are allowed and even by ashkenazim, many agree that if the bottle cap will be thrown away or is punctured, opening is ok. I have not heard or been able to find any opinion that says you can't open bottle on Yom Tov. Uneducated frummies will always find some way to make their life difficult.