The sour tang of the lemon is an indispensable flavouring in cooking. Shiny and yellow, the fruit varies in size and can have knobbly or smooth skins. Both the zest (or peel) and the juice are used, but the fruit is too sour to eat on its own.
To reserve their freshness, most lemons are washed and waxed before packing, although unwaxed lemons are also widely available. The unwaxed variety is best for slicing and adding to drinks, or if you wish to zest the rind for use in cooking. Waxed lemons keep longer and are best used if you just need the juice. If you do want to use the peel, scrub the skin well first.
Buy lemons that feel heavy for their size. Small, thin-skinned ones will give more juice, but thicker-skinned varieties will be better for zesting and for marmalade and preserve-making, as they’ll give more pith, which is essential for the setting process.
When removing the zest from a lemon, take care to just remove the coloured outer layer of the skin; the white pith has a bitter flavour. Remove the zest with the fine side of a grater. or use a vegetable peeler to thinly pare the rind, then cut into thin strips.
A few drops of lemon juice can transform a home-made mayonnaise or salad dressing, enhances the flavour of salmon and most grilled fish, and prevent discolouration of cut apples, pears and bananas. It is also used to make lemon meringue pies, lemon curd, lemonade, sorbets, hot and cold soufflés and icings.
Waxed lemons will keep for 2-3 weeks in a fruit bowl. Unwaxed lemons are best kept in the salad drawer of the fridge for up to 1 week.