Suet

Suet is the raw, hard fat of beef, lamb or mutton found around the loins and kidneys.
Suet has a melting point of between 45 °C and 50 °C (113 °F and 122 °F) and congelation between 37 °C and 40 °C (98.6 °F and 104 °F). Its high smoke point makes it ideal for deep frying and pastry production.
The primary use of suet is to make tallow, although it is also used as an ingredient in cooking, especially in traditional baked puddings, such as British Christmas pudding. Suet is made into tallow in a process called rendering, which involves melting and extended simmering, followed by straining, cooling and usually by repeating the entire process. Unlike tallow, suet that is not pre-packed requires refrigeration in order to be stored for extended periods.
Etymology.
The word "suet" is derived from Anglo-Norman "siuet, suet", from Old French "sieu, seu", from Latin "sēbum" ("tallow", "grease", "hard animal fat"). "Sebum" is from the Proto-Indo-European root *"seyb"- ("pour out, trickle"), so it shares a root with sap and soap.
Trade.
In the 17th century economy of the Viceroyalty of Peru, Chile's husbandry and agriculture based economy had a peripheral role exporting mainly suet, ch'arki and leather to the other provinces of the viceroyalty. The importance of this trade led Chilean historian Benjamín Vicuña Mackenna to label the 17th century the "century of suet" (Spanish: "siglo del sebo").
Cuisine.
Suet is found in several traditional British dishes. Suet pastry is soft in contrast to the crispness of shortcrust pastry, which makes it ideal for certain sweet and savoury dishes. Suet is most widely used in sweet British baked puddings, such as jam roly-poly and spotted dick. Savoury dishes include dumplings, which are made using a mixture of suet, flour and water rolled into balls that are added to stews during the final twenty minutes or so of cooking. In the savoury dish steak and kidney pie or steak and kidney pudding, a bowl is lined with a suet pastry, the meat is placed inside and a lid of suet pastry tightly seals the meat. The pudding is then steamed for approximately four hours before serving. Suet is also an ingredient of traditional mincemeat (it is also referred to as 'fruit mince' pie).
Due to its high energy content, suet is used by cold weather explorers to supplement the high daily energy requirement needed to travel in such climates. Typically the energy requirement is around 5,000–6,000 Cal per day for sledge hauling or dog-sled travelling. Suet is added to food rations to increase the fat content and help meet this high energy requirement.
Availability.
Suet can be bought in natural form in many US supermarkets and at local butcher shops. As it is the fat from around the kidneys, the connective tissue, blood and other non-fat items must be removed. It then needs to be coarsely grated to make it ready to use. It must be kept refrigerated prior to use and used within a few days of purchase, just like raw meat.
Pre-packaged suet sold in supermarkets is dehydrated suet. It is mixed with flour to make it stable at room temperature. Because of this, some care is needed when using it for older recipes that call for fresh suet as the proportions of flour to fat can alter. Most modern processed recipes stipulate packaged suet.
Cultural and religious restrictions.
Consumption of suet is forbidden according to the Jewish religion as it was reserved for ritual altar sacrifices. This restriction only applies to those animals which were used for sacrifices, and thus does not include wild animals such as deer.
Bird feed.
Suet-based bird feeders are favoured by woodpeckers, goldfinches, juncos, cardinals, thrushes, jays, kinglets, bluebirds, chickadees, nuthatches, wrens, and starlings.
Bird feed is commonly used in the form of cakes of suet, which can be made with other solid fats, such as lard. Rolled oats, bird seed, cornmeal, raisins, and unsalted nuts are often incorporated into the suet cakes.