Inexpensive, readily available meats are a modern phenomenon, made possible by advances in refrigeration and transportation. For most of human history, meat has been a luxury, and it was a point of pride to use "everything but the squeal" whenever an animal was slaughtered. For example, the blood of cattle and hogs is traditionally combined with other ingredients to make a type of sausage called blood pudding or black pudding. The Irish version is often available as a frozen specialty item and can be thawed or cooked from frozen.
Although eating blood isn't a comfortable notion for the squeamish, it's a concentrated source of protein with very little fat. If it's stirred regularly as it cools, it remains liquid instead of coagulating and can be easily combined with other ingredients. The Irish version, called black pudding, mixes blood with cooked oatmeal as a filler. It also contains coarsely chopped pork fat, usually the animal's back fat, because like any other sausage, it needs a balance of fat and lean to preserve its moisture and create a texture that can be sliced. The ingredients are finished by packing them into a mid-sized sausage casing.
Cooking and Freezing
Commercial black puddings are sold precooked. If you make your own black pudding, or have the good fortune to find a butcher who makes it fresh, it should be cooked before freezing. It needs to be done gently, because if it's boiled or roasted, the fat will run away and leave your pudding dry and crumbly. Instead, simmer the sausage gently in water at a temperature of 160 to 170 degrees Fahrenheit. After 20 to 30 minutes, the interior temperature of the pudding reaches a food safe 150 F when tested with a food thermometer. Cool and drain the pudding, then wrap it in plastic film wrap or a heavy-duty freezer bag for storage.
Heating from Frozen
Ideally, the black pudding should be thawed ahead of time by removing it from the freezer and resting it overnight in the refrigerator. If that's not possible, don't try to defrost it in the microwave. Microwave heating is uneven and produces dry, crumbly spots in your pudding. Instead simmer it gently in hot water, just as you would when cooking it for the first time. Once it's heated all the way through, you can remove it from the water, pat it dry and prepare it normally.
Irish black pudding is traditionally sliced, then pan-fried in a bit of butter until it's heated through and the edges are crispy. It's typically served at breakfast, though it also adds a flavorful element to lunch or dinner dishes where you'd use any other type of sausage. It also can be sliced cold, once cooked or thawed, and used in sandwiches or on cold deli plates with cheese and bread or crackers. If you're preparing a casserole or similar dish, such as braised cabbage, you can skip the thawing step and add your pudding directly to the dish as it cooks.