YES!!! Bottled lemon juice is just as good! On average a medium sized lemon will produce about 3 tablespoons of fresh lemon juice. This is not an exact amount. Every lemon depend on size and ripeness will produce a different amount. So 3 tablespoons is an average/estimate. For this recipe it calls for 7 to 8 medium sized lemons which is about 1 1/2 cups.