Traditionally, it was cut from a whole side of pig, with the leg still attached, which was intended for processing into bacon. The whole side was cured with a mild cure.
After that, gammon would be cut from the leg area where ham would normally be cut from. Even so, it’s not technically a “ham ham”, because it’s not cured separately, and because it’s only cured as much as bacon is. It has a mild flavour, because it hasn’t undergone some of the more pronounced cures that can make ham longer lasting.
It differs from North American brine-cured ham in that North American brine-cured hams are cured on their own, and therefore tend to be saltier. The Gammon is cured with brine, cured in brine, or brine-injected, while it is still attached to a side of pork, and it ends up less salty.
It may be smoked or unsmoked, depending on whether the side of pork was intended for smoked or unsmoked bacon.
The Gammon may be sold whole as a joint, or in slices.
A whole joint can range from 2 to 9 pounds(1 to 4 kg), and be boned or on the bone. A whole joint will have skin on it.
The slices may be sliced thinly as “slices” or sliced thickly as “steaks.” They may also be sold as “ends” (the last slice from the joint), or diced (for quiches, omelettes), or as hocks for soup.
Gammon needs cooking. A whole joint is often boiled.
The definition of Gammon is becoming a bit slacker these days, and is being used to refer to any leg joint suitable for boiling and / or baking, whether or not it underwent the bacon cure.
For a joint, allow 5 to 6 oz (150 to 170g) per person.
To boil a joint, cover it with cold water, add any seasonings desired (cloves, peppercorns, bay leaves, etc.) Bring water to a boil, then once a boil is reached, reduce it to a simmer and allow 20 minutes per pound (450g), plus 20 minutes “for the pot.” The internal temperature should reach 170 F (77 C.) Once cooked, you can serve with a parsley sauce, or serve as a cold-cut meat.
If you are going to bake it, just simmer for 10 minutes per pound (450g) plus 10 for the pot. Then drain, let cool until it is safe to handle, and peel off the skin. Wrap in foil, place in an oven heated to 350 F (180 C) until the internal temperature reaches 170 F (77 C.) If you want to glaze it, about half an hour before you figure it is done, crank the heat to 425 F (220 C), remove from oven, take off the tin foil, glaze, and put back in the oven. Many use hard cider as a glaze, pouring it over the joint when they first put it in the oven.
Grill or fry Gammon Steaks (1/2 to 3/4 inch thick / 1 to 2 cm) for 4 to 6 minutes per side, or bake at 350 F / 180 C / Gas mark 4 to 5 for 15 to 20 minutes.
Literature & Lore
“The custom of eating a gammon of bacon at Easter was this – namely, to shew their abhorrence of Judaism at that solemn commemoration of our Lord’s resurrection.” — Chambers, Roger. The book of days: a miscellany of popular antiquities in connection with the calendar, including anecdote, biography, & history, curiosities of literature and oddities of human life and character. London: W and R. Chambers Ltd. 1832. Volume 2. Page 440.
One old French word for “ham” was “gambon” (now “jambon”), from the old French word for leg “gambe” (now “jambe”). The Italian word for leg is still “gamba”. A slang expression for legs in English is still “gams”.