Here’s the thing. You can’t fill a cheddarwurst with unadulterated Cheddar cheese. You run the risk the cheese will separate – not just melt – into stringy casein and a pool of grease. Those two components won’t re-combine on cooling; they just stay separate, and will make your cheddarwurst oily. Some sausagemakers attempt to forestall this problem by using something called “high temperature cheese,” which is processed with a higher acid content to inhibit melting, but those cheeses are never of high quality and the inhibited melting under 205C/400F gives them a rubbery and sometimes chalky texture.
The solution? Process the cheese with sodium citrate. This allows you to emulsify the cheese with water (or a similar liquid) and is basically how Velveeta and Kraft Singles are made. Best of all, this method allows you to use any cheeses you like, and not limit yourself to the mystery blend of mild cheeses that characterizes American cheese. Even if it melts during cooking, it won’t disintegrate into greasy orange cheese strings; it just melts. When your sausage cools, it’ll firm right back up.
12g sodium citrate
200g beer, preferably one that pairs well with the cheese you selected
400g cheeses, any type (I used a blend of 150g each 4-year old Wisconsin cheddar, a mild Wisconsin cheddar (hence the orange color), and 100g Gouda), all grated
Combine the sodium citrate, beer, and salt; blitz with a stick blender or in a vitaprep to hydrate (alternatively, whisk well and let stand about 30 minutes, whisking every 10 minutes). Bring to a simmer. Add the cheese and blend with a stick blender until completely emulsified. If your cheese is finely grated, you may simply be able to whisk it in.
Pour into a clingfilm-lined loaf pan or a plastic container such as a Glad container. Chill until solid. Use as directed above, or slice for grilled cheese sandwiches, or melt into hot macaroni for great macaroni and cheese.