Oxtail doesn't actually come from an ox — this cut of beef commonly comes from a cow's tail. The meat has a lot of flavor but requires a slow and low cooking heat. Preparing oxtail in the slow cooker provides the moist heat needed to help tenderize oxtail. Completely cover it with water or a seasoned marinade when cooking the meat, and allow from eight to 10 hours of cooking time. Browning the meat before adding it to the slow cooker and using a range of seasonings also can add to the dish's overall flavor.
Salt and pepper are not the only seasoning options when preparing oxtail, and cooking the meat in a slow cooker gives it plenty of time to absorb the flavors of your seasonings. Thyme, yellow or brown mustard, chopped onions, and tomato sauce are all popular additions to oxtail dishes. Depending on their location, some cooks also may add chopped celery, carrots, potatoes, and green peppers.
When you cook oxtail in the slow cooker, you should use the lowest temperature heat setting. Browning the meat before placing it in the slow cooker improves its taste and appearance. This step is similar to preparing meat for braising. You should heat olive oil in a skillet on your stove and brown both cut surfaces of the oxtail. If the cuts are thick, then the meat can be turned on its edge to brown the sides.
For best cooking results, slow cookers should be at least half-full but not more than two-thirds full. Filling them to the brim increases the cooking time and causes uneven cooking. The amount of liquid you add also affects the cooking time. It should be sufficient to completely cover the meat without being excessive. Any recipe designed for cooking oxtail in an oven on low heat can be adapted for the slow cooker.
The amount of oxtail being cooked will help determine cooking time. A recipe that requires from two to three hours in the oven will take at least eight hours in the slow cooker on low. Cooking in the slow cooker on a high-heat setting will only take from four to six hours, but high heat is not recommended for this dish. The best way to speed the cooking process in a slow cooker is to start your dish and resist the temptation to lift the lid for a peek inside. Each time you open the lid, you increase the cooking time by 15 to 20 minutes.
One advantage of preparing oxtail in the slow cooker is that it lets you also creates savory gravy using all the meat juice. About an hour before the end of the cooking time, you can mix water with cornstarch or plain white flour, open the lid and add the mixture to the cooking pot. A quick stir of the slow cooker's contents will mix and incorporate the thickener with the juices and create a flavorful gravy by the time cooking is done.