After reading about it here, I finally got to Karls Sausage Kitchen after a hike at the Breakheart Reservation a couple of months ago and have gone there several times since. It is really worth a drive! All their sausages are made on-premises and you can see through to the back where they are made it is reassuringly immaculate.
The sausages labeled bratwurst but referred to by everyone as white bratwurst are very light in both texture and color and beautifully seasoned. I dont have a lot of bratwurst experience but what they really remind me of is the weisswurst I used to get in Germany. I am guessing that there is a high proportion of veal in them. Absolutely delicious.
There is another variety called rostbratwurst, which has more coarsely ground meat with a little more color and a bit of celery seed in the seasoning. Also very good.
The smoked bratwurst is a very large link that seems to be different in composition from either of the other bratwursts it is quite smoky and seems (from the redness) to have been smoked over wood. Tasty, but my least favorite of what Ive tried. (Some family members beg to differ.)
Smoked polish sausage was smoky and nicely seasoned I really liked it but bore little resemblance to the kielbasas I have gotten from the Polish deli in South Boston (cant remember the name, across from and related to Café Polonia).
Andouille is quite spicy with multi-dimensional seasoning and is much better than anything else I have found locally (no idea how it would stack up against New Orleans andouille). Sliced up in kale and white bean soup it is nothing short of ambrosial.
Karls has a variety of hams they will slice to order black ham, a beautiful single muscle type, makes a delicious sandwich. They smoke their own bacon which is very good. (Am working up to the triple-smoked variety.) Also, their garlic salami is the best I have tasted in many a long year. They have a nice selection of German breads, too.
If you go, many of the smoked sausages are hanging from hooks on the wall behind the counter, while the fresh ones are all in the refrigerated case.
Karls Sausage Kitchen, Route 1 North, just past the Walnut Street overpass, Saugus.