Does homemade buttermilk really taste the same in a cake recipe?

I forgot to buy buttermilk for the pound cake I want to make, and I remember a coworker telling me years ago her mom always made her own buttermilk with whole milk and vinegar. Is it true? Does that work? What measurements do you use? I already know there are recipes online, but I would like to hear from jelly who has actually used both store bought buttermilk and homemade, so I can feel reassured. I will be serving the cake to some guests, and like all cakes and pies you can’t really taste like you can when you cook. I guess I could make a mini mini cake in a small pirex to taste, but if it is terrible it is a lot of time, takes almost 2 hours start to finish, and lots of flour, sugar and eggs.

Thanks!