By altering processing procedures and meat and spice ingredients, a wide variety of sausages can be produced. An absolute classification of all sausages into specific categories is very difficult, since any given sausage may be produced in a number of different ways. Below is a very simple and broad classification of the various sausage types based upon processing procedures and product characteristics:
Fresh sausages: Raw sausages (must be cooked by consumer), and do not contain the "curing" ingredient nitrite. Examples include fresh pork sausage, fresh Italian sausage, and fresh bratwurst. Since these are fresh meats, they should be kept tightly wrapped and refrigerated up to one week. They may be frozen up to two months.
Fresh Smoked sausages:Treat as fresh sausage and all fresh meat. These meats have been cured, and the smoking gives a characteristic flavor and color. Sausage varieties include: Smoked Polish, Italian and Bratwurst.
Cooked sausages: Ready-to-eat sausages which are fully cooked during manufacture. Many are also smoked. These products may be eaten without heating, but often are reheated before serving. Examples include wieners, bologna, cotto salami, smoked sausage, cooked bratwurst and liver sausage.
Cold Smoke: These sausages are smoked at temperatures under 200° F. and use cures, which along with the smoke helps preserve and give a characteristic flavor and color.
Hot Smoked: These sausages are smoked at temperatures above 200° F and do not require cures. Smoking gives a characteristic flavor and color.
Fermented sausages: Have a characteristic "tangy" flavor due to the accumulation of lactic acid produced from a microbial fermentation of added sugars (or in some cases by direct addition of encapsulated acids). These sausages are dried to varying extents during processing. Semi-dry fermented sausages (slight drying) include summer sausage and snack sticks. Dry fermented sausage (extended drying) include pepperoni, hard salami, and Genoa salami. With the proper amount of acidification and drying, these sausages can be shelf stable (do not need to be refrigerated). Continued with Semi-Dry and Dry Sausage below.
Meat loaves and jellied products: Mixtures of chopped meat usually processed in pans or metal molds. Jellied products consist of cooked meat chunks suspended in gelatin. Examples include pickle and pimento loaf, honey loaf, jellied roast beef loaf and head cheese.
Semi-Dry Sausage: Summer Sausage is an example. These are cooked, then carefully dried to remove some of the moisture. They keep a short time without refrigeration (3 to 5 days). If refrigerated, they remain delicious up to three weeks. Semi-Dry varieties are softer than Dry Sausage.
Dry Sausage: These are cured under controlled temperatures and humidity for as long as 90 days. Ready to slice and eat. These will keep even longer if refrigerated, but should not be frozen. Varieties include: Hard Salami, Genoa and Pepperoni.