Now, I know what you're thinking, "But what about all the recipes online that say it's okay to put raw ground beef in a slow cooker?" Well, those recipes might be bull-ing you (sorry, I couldn't resist), because while it's technically possible to cook ground beef in a slow cooker, it's not always the most reliable method. The problem is that the temperature in a slow cooker can fluctuate, and if the beef isn't cooked to a safe temperature, you're playing with fire (or at least a nasty case of food poisoning).
On the other hand, if you brown your ground beef before adding it to the slow cooker, you're golden (or at least, your stomach is). Browning the beef not only adds flavor, but it also helps to kill off any bacteria that might be lurking on the surface. So, if you're looking for a foolproof way to cook ground beef in a slow cooker, browning it first is the way to go.
10 Easy Slow Cooker Ground Beef Recipes