I am making an apple pie but don't have lemon juice. I read that I could sub vinegar. Is this correct and how much for 2 tbsp of lemon juice?
Yes, the vinegar will work. Apple cider, if not, then white, Same amount. (You can omit altogether. Serve ice cream or slice of cheddar with warm pie. No one will notice missing lemon juice.
You could also use a touch of orange juice, or any acid really. A couple months ago, I threw together an apple crisp and didn't have anything to keep the apples from turning brown [I wasn't baking it right away] so randomly decided to add a bit of something I found in the fridge which contains lime. It worked great and the flavor turned out really good too! The secret? ready-to-drink Mojito, lol.
1:1 Ratio is fine.