Making a delicious hamburger is a relatively simple process, but ensuring that the burger stays warm and moist for hours can intimidate even experienced cooks. The next time you're entertaining guests, consider cooking your burgers a few hours in advance and storing them in liquid until it's time to eat. It cuts down on the stress of preparing all the food simultaneously and gives you the freedom to socialize with your guests. This method is particularly useful if you're making a large batch of sliders.
Always use ground beef with a relatively high fat content. Although lean ground beef works well for dishes like meatloaf or meatballs, hamburgers require the high fat content for moisture and flavor. Ground round and ground chuck, each containing about 20-30% fat, make the best burgers.
Form your burgers into patties and store in the fridge up to 24 hours. Sprinkle salt and pepper on both sides of the patties just before cooking. If you add the salt and pepper too early, it will steal the much-needed moisture from the patties. Cook the burgers as you prefer.
Fill an oven-proof pot or baking dish with 1 or 2 quarts of beef broth, depending on how many burgers you're cooking. The burgers should be completely covered by broth to avoid any drying out. Once the burgers have finished cooking, add them to the beef broth and cover with aluminum foil. Place the pot or baking dish in the oven on low heat, just high enough to keep the burgers warm. Storing the burgers in liquid in a heated oven will keep them warm and moist for hours.
Remove the burgers from the broth and place them on buns. Top with your favorite vegetables and condiments and serve immediately.