How to select for best flavor:
Select firm, glossy fruit that seems heavy for its size. A slight greenish cast to the skin is desirable because it means the juice will be more acidic. Avoid lemons that are shriveled and hard-skinned or soft and spongy. Decay will show up first at the stem end, so check it carefully. Large lemons with course skin will have less juice than the smaller, thin-skinned varieties.
Peak of the season:
Lemons grow and ripen all year round. If you look at a lemon tree, you are likely to see blossoms, buds and fruit at all stages of maturity at the same time. The large Eureka lemons are more plentiful in the summer. Smaller lemons are more common in the winter.
Lemons are one of the best sources of vitamin C. The juice, when it is very fresh, has a much greater vitamin C content than the whole fruit. Lemons are also an excellent source of potassium. They are often recommended for people who suffer from arthritis. One lemon has about 15 calories, no fat and 1 mg. of sodium. One cup of lemon juice, unsweetened, has about 60 calories, no fat and 2 mgs. of sodium. Sugar will add a significant amount of calories.
Lemons are a traditional cure for scurvy. The Mongols, who conquered Europe under Genghis Khan, brought lemonade with them from Asia.