The Refrigerator Method

• Refrigerator thawing is the slowest method to thaw a rump roast, but it's also the safest. When placed in a refrigerator set at 40 degrees Fahrenheit, a rump roast will thaw in one to two days. Place a plate or baking sheet underneath the rump roast to catch any drips as the roast thaws. Dripping meat juices could contaminate other items in the refrigerator, in addition to the mess they cause.

The Cold Water Method

• For faster results, place a rump roast, still in its wrapping, in a bowl filled with tepid water. Replace the water every 20 to 30 minutes as it cools. Another method is to place the meat in a bowl in a clean sink and turn the faucet to a slow, but steady, stream of cool water. The water runs over the meat so it stays at a consistent temperature as it thaws. Both these methods safely thaw rump roast while minimizing bacterial growth. Plan on two to three hours to get the job done. Cook a roast thawed in water immediately.

In the Microwave

• You can also thaw rump roast in the microwave in 15 to 20 minutes. Unwrap the roast and place it in a microwave-safe plate. Microwave on low, or on the defrost setting for 10 to 20 minutes, or as recommended by the microwave manufacturer. Many microwaves have a customized defrost setting based on the weight of the roast. Keep in mind that microwave thawing can cause hot spots in the roast and cook it unevenly. A roast thawed in the microwave should be cooked immediately.

Keep It Safe

• Never thaw meat on the kitchen counter. Bacteria on the roast begins to multiply at temperatures between 40 and 140 F, especially if the roast is left out longer than two hours. Thawing in this way puts you at risk for foodborne illness. Play it safe and thaw your rump roast in the refrigerator, the microwave or cool water.