While grilling is the traditional way to cook bratwurst, poaching can be a good cooking option if you are running low on time and want the ease of cooking on the stovetop or in the microwave. In fact, in many German and Northern European households, poaching is the norm, not the exception -- a typical meal might include poached bratwurst, sauerkraut and boiled potatoes, with the more highly seasoned pork and veal bratwurst adding flavor even without grilling.
Poaching water is well below the boiling point and below the level of simmering. When you poach, keep the temperature of the water so low that it is just "smiling" or quaking, with no bubbles breaking the surface as they do now and then with simmering. Poaching is typically used for more delicate foods like fish or fruit rather than for bratwurst, but it also works perfectly well for bratwurst.
Some commercial bratwurst comes precooked. For these sausages, place them from the refrigerator into a pot of water that is at the poaching stage and cover the pot. Because the wursts are precooked, all you need to do is heat them all the way through. Depending on the size of the bratwurst, heating takes from 3 to 4 minutes.
Fresh bratwurst is red and looks like the raw pork and veal that it contains. Poach fresh bratwurst 8 to 10 minutes, or until it reaches 160 degrees Fahrenheit on an instant read thermometer. You'll also know it's cooked if the juices run clear when you lift it up and pierce the casing with a knife. Or, to be on the safe side, take the bratwurst out of the pot, cut a good-sized slit in the sausage and make sure that the meat is completely gray and no longer pink at all.
With microwave poaching, you have less control of the water temperature and may need to test the bratwurst more frequently with a meat thermometer or a knife. Place the bratwurst in a microwave container with enough water to cover it and cook it on high for about 2 minutes. Turn the wurst over and cook it another 2 minutes, then check the doneness again. If there is still any pink left, cook again for another minute.
Poaching Before Grilling
Poaching before grilling gives you the best of both worlds -- you can be sure the meat is cooked thoroughly and you still have attractive grill marks and a tasty, brown char. Poach the bratwurst in either water or a beer of your choice until it is just short of being cooked thoroughly, about 5 minutes. Drain the bratwurst and grill it on a stovetop grill pan or a charcoal grill for another 6 minutes, turning it until it's browned.