Blood sausage is one of the oldest and most traditional of French foods, with inscriptions and documents stretching back 2000 years showing its production.
Up to the second world war, it was common for families in rural areas to keep a pig, which was raised to be slaughtered at the beginning of winter. This was a major event each year, with the entire family working from dawn to dust to slaughter, bleed, butcher and process every part of the pig. Nothing was wasted, even the blood and bones were used. Not only was this an important source of meat, but also a source of food during the lean winter months. As this tradition of keeping a family pig for slaughter had faded from being commonplace to being almost unknown, Boudin Noir has declined from being a staple of the average families diet to being merely one of many types of sausage available. However, you will still find Boudin Noir in any serious butcher shop.
Nowadays Boudin Noir is prepared by butchers (or factories) using modern methods. Before being stuffed into its casing, the blood is mixed with various ingredients, depending on the recipe of the producer. These typically include some of the following: herbs, onions, cream, fat, fruit, vegetables, grain, apples or chestnuts.
Although the name "blood sausage" may be unattractive to some, it is essentially the same idea as British "black pudding", which is not uncommon as part of a British fried breakfast. Except when fat or cream are added, it is a lean and healthy source of protein.
Unless pre-cooked, Boudin Noir does not keep for a long time, so should be prepared and eaten within a day or so of being purchased.