The knack (from the German Knackwurst, meaning ‘snap sausage’, named for the audible snap of the taut casing when bitten) is Alsace’s signature fresh sausage: a mildly smoked, emulsified pork sausage in a natural sheep casing, and the foundation of the region’s street food and casual dining culture. The knack sits alongside a family of Alsatian sausages — Strasbourg sausages, cervelas, and saucisses de viande — each with distinct characteristics. The knack is produced from lean pork and pork back fat (typically 70% lean, 30% fat), seasoned with salt, white pepper, mace, and a hint of coriander, then emulsified in a bowl cutter (cutter) to produce a fine, smooth farce. This farce is stuffed into narrow sheep casings (22-24mm diameter) and twisted into links of 12-15cm. The sausages are lightly smoked over beechwood for 20-30 minutes at 60-70°C (just enough to set the casing and impart a faint smokiness without cooking the interior), then cooled. To serve, the knack is heated — never boiled. The classical method: place the sausages in water at 75-80°C (well below simmering) for 10-12 minutes until heated through. At this gentle temperature, the casing tightens around the expanding filling, creating the taut snap that gives the knack its name. Boiling water bursts the casings, releasing fat and flavour into the water and producing a flabby, deflated sausage. The heated knack is served immediately on a warm plate with mustard (Maille or Alsatian sweet mustard), a pretzel (bretzel), and optionally horseradish cream and cornichons. In the choucroute garnie context, knack are added during the final 15 minutes, nestled among the sauerkraut and smoked meats. The quality test for a knack is simple: when you bite through the casing, it should resist momentarily, then snap crisply, releasing a burst of hot, juicy, savoury filling.
Emulsified pork sausage in natural sheep casing. Lightly smoked over beechwood (60-70°C, 20-30 minutes). Heat in 75-80°C water, never boil. Casing should snap audibly when bitten. Serve with mustard and pretzel. Add to choucroute in final 15 minutes.
The best knack are purchased from an Alsatian charcutier, not supermarket packages. To test water temperature without a thermometer: the surface should shimmer with tiny bubbles but not break into a simmer. Pan-frying knack in butter until the casings blister and brown is an excellent alternative to poaching, producing a crispier exterior.
Boiling the sausages, bursting casings and losing flavour. Pricking the casings before heating (releases juices). Overcooking until the fat separates and the texture becomes grainy. Using artificial casings that don’t snap. Serving lukewarm rather than hot.
La Cuisine Alsacienne (Simone Morgenthaler)