Weisswurst (White Veal Sausage with Parsley and Lemon)

Variations

• The emulsifier here is myosin, and the guide lists it. Why sauces split carries myosin among its emulsifiers — protein the salt has drawn out of the muscle — and names this sausage as what it is for. What sets it apart from the rest of that list is the object rather than the chemistry: the others are poured or spooned, and even the one that sets is soft enough to roll. This one you chew.
• It also runs the other way. The guide opens from "an emulsion is always trying to separate" and ends with how to rescue one. A sausage emulsion is set permanently by heat — once cooked it can never break again. The guide puts it as cooking being the completion, where every other emulsion in it rests on the premise that it is always trying to separate. In exchange the danger sits at the beginning rather than the end. Hollandaise breaks because it got too hot at the finish; this breaks because it got too warm while being mixed. And none of the guide's first aid is available: you cannot whisk in cold water, and you cannot dribble a broken sausage paste into a fresh yolk.
• Sundae is the same operation with a different glue. Filling a casing and twisting it off is identical. What holds sundae together is blood coagulating with heat; what holds this together is a cold protein emulsion. So they want opposite things — sundae has to be pricked at about five minutes to let steam out, and this must never reach a temperature where steam could form.
• Mititei has no skin on purpose, shaped by hand and grilled. With no casing the aim is the opposite: a texture you can feel the grain of.
• Swedish meatballs, köfte and meatloaf are not emulsions. Breadcrumb and egg fill the gaps between the meat particles and bind them, so a cut face shows the grain of the meat. Cut a weisswurst and there is no grain at all — it is homogeneous. That cut face is the evidence of whether the emulsion worked.
• Currywurst buys this sausage. The only other page here where a sausage is the subject starts from a finished one. This page is the step before it.
• The noon bells. Munich says a weisswurst must not hear the midday bells. It sounds like a romantic rule and the reason is technical: there is no curing salt in it at all. That is why it is white rather than pink, and it is the same reason it does not keep. Before refrigeration it was made at dawn and had to be sold by midday. The colour in the name and the rule come from one cause.
• Why it is not grilled. The usual story is that in 1857 an inn on Munich's Marienplatz ran out of sheep casings, used thicker pork ones, and poached them in hot water rather than risk them bursting on the grill. It is not a documented story, but it does explain why poaching is this sausage's identity rather than a preference. Grill one today and the emulsion still breaks.
• Do not cut the fat. 25-30 percent is right. Less and it is dry; more and the emulsion is unstable and you get oil floating in the pan.
• With no veal, chicken breast will keep it pale but tastes much thinner. All pork darkens it, at which point it is no longer a white sausage.

Tips

• 12C is the only number in this dish. One probe thermometer matters more than any other piece of equipment here.
• The ice is an ingredient. Swap it for water and the temperature runs away; leave it out and there is no water for the emulsion.
• Do not cut the salt. Below 1.8 percent the paste never turns tacky and the sausage comes out crumbly. It is a structural quantity, not a seasoning one.
• Do not boil. Staying under 75C is the whole of the cooking instruction.
• Fill loosely. The paste expands a little as it sets.
• Parsley and lemon last, and by hand.
• Eat them the same day. With no nitrite there is no keeping quality. To hold them longer, poach, chill in iced water and refrigerate, then bring back to 75C to serve.
• Cut one open to check. Homogeneous means you kept the temperature; visible meat grain and beads of fat mean you lost it.