Rarely eaten on their own, lemons are an indispensable ingredient in the kitchen, useful for their aromatic qualities and their sharp, acidic flavour. Lemon juice can be used instead of vinegar in sauces; for seasoning vinaigrettes and mayonnaise; and as an instant dressing for fish and shellfish. It can also be squeezed over certain fruit and vegetables, such as apple and celeriac, to prevent them from discolouring. Lemon zest is used to add flavour, for example in gremolata, or shredded and used as a classic garnish. Lemon wedges can be used to squeeze over many different dishes to enliven them as it acts as a flavour enhancer. Lemon is also a classic flavour for sweet dishes such as soufflés and ice creams. Shop–bought lemons have been picked while still green to prolong their shelf life and they may also be waxed to stop them drying out. Choose your lemons with care and pick ones that are firm, fragrant and heavy—this is a good indication that they are juicy. Different varieties have different degrees of acidity so taste the juice to make sure you will get the right effect—a tarte au citron made with sweeter lemons will be very different from one made with sour acidic lemons. The thickness of the fruit’s skin is important too—thicker skins are better for making candied peel and thinner ones for slicing and using cooked in dishes. The acidity in lemons is also helpful in setting jams and jellies.
Lemon goes with — avocado, chicken, lamb, oysters, seafood, veal