The blood used is best fresh before it has coagulated, so the sausages are usually made on the day the animals are slaughtered.
It is usually mixed with other ingredients such as meat, fat, spices, flavouring such as onion, and grains such as barley or oatmeal.
As with other forms of sausage, both fresh and cured types of Blood Sausages are available, with both having distinctive tastes.
In the United Kingdom and in Ireland, called Blood Sausages are called Blood Pudding. Slices of this can be eaten as is, though slices are traditionally fried up as part of a traditional fried breakfast. Bury in Lancashire, England, Clonakilty in Cork, Ireland, and Fife in Scotland are well-known for their blood puddings
In Germany, Blood Sausage is known as “Blutwurst”, which means “blood sausage.” It can be eaten as is, or fried up. Zungenwurst (“tongue sausage”) is blood sausage with pickled pig’s tongue in it.
Blood Sausage is France is “Boudin noir”, made from pig’s blood. It can be served as is, or heated. Boudin Noir Creole, made in Louisiana, is made with pig’s blood, and rice (see separate entries for each.)
In Belgium, Blood Sausage is called “bloedworst”, “zwarte pensen”, “zwarte triepen “, or ‘beuling.” It is sold in sausages about the size of a banana, and cut generally into ¾ inch (2 cm) thick slices for frying up, though it can also be eaten room temperature.
In the Netherlands, Blood Sausage is also called “Bloedworst.” This is usually sold in 4 inch (10 cm) wide slices cut ½ inch (1 cm) thick from a large sausage. The slices are fried up for serving in a frying pan.
In Spain, and in some Spanish speaking countries in Latin America, Blood Sausage is called “morcilla” (see separate entry.)
In China, “blood tofu” (“xue doufou”), made from pig or duck’s blood is a skinless sausage that is cut into pieces for cooking.
In Tibet, blood from yak’s is used.
The Romans made Blood Sausage.