Being Swedish, I feel privileged to reply.
This is a recipe from Svensk Kokkonst (=Swedish Cookery) from 1918. I've tried it myself, and it's completely reliable. It calls for light cream, which by then also served as a lactic acid fermentation starter. Nowadays, milk is pasteurized, so I use to add yoghurt as a starter. It's important to give the sausage time to ferment. The sour taste is an attribute of prinskorv (although there are unfermented types too). I would substitute ale for the small beer. Prinskorv means Prince Sausage, which probably comes from its small size. As with most old recipes, measures are not very exact. I give the recipe in its original form. The seasoning should be very subtle and discrete.
The classic serving of prinskorv is fried with scrambled eggs.
Prinskorv
1½-2 kg pork
1 kg back fat
1 kg veal
Salt, pepper
A little cayenne
A little powdered ginger
A little powdered allspice
1/4 litre cream
1/4 litre small beer + a little distilled vinegar
Veal stock
Sheep casings
(Lactic acid fermentation starter)
Soak the casings for a few hours in the small beer and vinegar. Grind the meat very finely. Mix with spices, cream, starter and stock. Emulsify. Stuff into casings and make 4-6 cm/~2 inch links. Let ferment in a hot place for 24 hours. Continue following this recipe http://www.wedlinydomowe.com/sausage-re ... rankfurter from paragraph 4.
NB that this recipe doesn't contain cure. I recommend adding cure.