Most British people think of cranberries as little more than a condiment for their Christmas turkey, but these tart little berries deserve more attention. The health focus on cranberries of late has been on their apparent effect in preventing urinary tract infections. Researchers are not sure of the precise mechanism, but it may be that the tannins in the berries (which contribute to their mouth puckering tartness) help fight certain bacteria. Cranberries, like a number of other berries, also contain ellagic acid, a cancer-fighting phytochemical.

Cranberries are too tart to eat raw or in any unsweetened form, but they can be combined with sweeter fruits, such as apples or pears, so that very little additional sugar is needed. Dried cranberries (sometimes called craisins), which are usually sweetened, can be substituted for raisins or other dried fruits in compotes, cookies, and muffins.

The wild cranberries favoured by early settlers in America have been largely replaced by cultivated varieties that are larger, glossier, and have more flavour. Four major varieties of cranberries are now grown commercially in the U.S. They vary somewhat in size and colour, but all taste virtually the same.

Only about 10% of the commercial crop is sold fresh; the rest is used either in juice or cranberry sauce. Fresh cranberries are available all year round, but are more plentiful beginning in September and through to December. Frozen cranberries have become increasingly available.

Cranberries are usually sold in plastic punnets , and since they're firm, rather than soft like most other berries, they're likely to be in good condition. Check them for firmness and a good red colour; the punnet should contain a minimum of pale berries and debris.

Cranberries store well, about two weeks in the refrigerator, and a year in the freezer. You can put bags of cranberries in the freezer with no further preparation, and can cook with the frozen berries without thawing them.

It's easy to clean and pick over cranberries by placing them in a basin of cold water; twigs, leaves, and unripe berries are easy to spot because they float to the surface. The process should be done quickly, though, you don't want to soak the berries. Cook cranberries with a small amount of liquid until the berries pop. Fold cooked berries into homemade apple sauce or compote, or try adding them to sliced apples or pears to fill a pie.