lemon juice
The juice pressed from lemons, sour and bright; used to add acidity, balance rich or fatty dishes, and -- combined with dairy -- to thicken or deliberately curdle.
Buying guidance
Fresh-squeezed has noticeably brighter flavor than bottled, which is often made from concentrate and tastes flatter and slightly bitter by comparison; keep bottled on hand for convenience but reach for fresh when lemon flavor needs to stand out. One medium lemon yields roughly 2-3 tablespoons of juice.
Substitutions
- Fresh lime juice -- similar acidity with a more floral, sharper edge; a close substitute in most savory dishes.
- White wine vinegar or mild white vinegar -- provides acidity without citrus aroma; use somewhat less, since vinegar is often sharper-tasting than lemon juice.
- Bottled lemon juice -- convenient stand-in for fresh, but flatter in flavor.
Tips & common mistakes
Zest a lemon before juicing it, not after -- once squeezed, the fruit collapses and the peel becomes hard to grate cleanly. Fresh lemon juice also loses its bright edge under sustained heat, so for the brightest flavor stir at least part of it in near the end of cooking rather than simmering it the whole time.
Storage
Fresh-squeezed juice is at its best within a day or two, even refrigerated, and freezes well for longer keeping -- portion it into an ice cube tray so a spoonful or two can be thawed at a time. Bottled juice is shelf-stable unopened for months and, thanks to added preservatives, keeps reasonably well in the fridge after opening too.