Two of the most common varieties of lemon – Meyer and Lisbon – are interchangeable in many recipes. For the record, Meyer lemons, with their often bumpy-skinned, large, round, fleshy fruit that have sweetish juice and pith, are not true lemons. Cooks love them because they’re easy to squeeze and yield plenty of juice, and gardeners love them, too, because they bear fruit for most of the year. However, they are sweeter than a true lemon, and sometimes do not add enough acidity to dishes that require the bracing freshness of a Lisbon lemon. More often than not it’s a case of using what you’ve got, but if I could choose I’d use Meyer to squeeze over barbecued or grilled fish and cutlets, or to rub over a chicken before roasting; and I’d use Lisbon (or Eureka/Yen Ben/Genoa) for Asian and Mediterranean dishes, vinaigrettes, lemon tarts, and in dishes calling for a more concentrated lemon flavour. And in a G&T? Probably a sour lemon (Lisbon etc), because it will cut the sweetness of the tonic and make a more refreshing drink, but as I would most likely have a Meyer lemon to hand, that’s what would make it into the glass.
Lemons are easier to squeeze when they’re at room temperature, but they can rot in warm humid conditions. Keep one or two in the fruit bowl, and the rest refrigerated, or leave them on the tree until you need them. If lemons are very cold, or not very juicy, roll them several times with the hand to help release the juice, or warm them in a microwave. An average lemon will yield around 1 tablespoon of grated zest and 2½ tablespoons of juice.
If you’re lucky enough to have a glut of lemons: squeeze and strain the juice and pour it into ice-cube trays to freeze. Pack the frozen cubes into plastic bags and thaw as required.
To check if lemons are ready to harvest, shake the tree and ripe lemons will fall off. If you can’t wait for lemons to ripen, twist your chosen lemon around and around until it snaps free. This will leave a sealed end and prevent disease forming on the tree and ensure a healthy crop next year.