Lemon juice may be essential in many recipes, but if you're in the middle of baking or making dinner and you've run out of lemons, substitutes abound. As long as you know why the lemon juice is on the ingredient list, it's easy to find an adequate replacement.
Citrus Flavor
Lemon juice adds a citrusy kick to savory salad dressings and marinades and tartness to frostings and whipped cream toppings. If you don't have lemon juice, use the same amount of orange, pineapple or lime juice instead.
Acidity and Sweetness
Bakers add a few teaspoons of lemon juice to sliced apples to prevent discoloration when making apple pie. Use maple syrup, agave syrup or honey instead. Coating the apple slices will slow the oxidation process, but remember to reduce the amount of sugar called for in your apple pie filling recipe.
Acidity and Savoriness
Use vinegar or white wine in place of lemon juice in salad dressings and marinades. Simply cut the amount in half.
Uniquely Lemon Flavor
Lemon zest is the outermost layer of lemon peel. It contains lemon oil, which lends a specific, pungent aroma and flavor to a dish. Use it in salad dressings, marinades and baked foods. If you don't have a fresh lemon to take zest from, use dried zest.