but then I had friends in Brazil say, "How can I make that if I don't have this...?"
Well, I did a little digging around and I have some good info for you.
If you are needing sour cream for a recipe and do not have access to it (like those of you in Brazil), there are several different things you can use depending on what you are going to use it for. Baking, dips, toppings... they all have their own ways to make a good substitute.
Substitute one of the following for each 1 cup of sour cream:
1 cup regular milk + 1 tbsp. white vinegar + 5 minutes wait time = buttermilk
*If you are using yogurt, strain it through a cheese cloth first and then let sit in refrigerator for 1 hour.
Enjoy your chocolate-banana-bread or whatever else it is you are eating!