Cheddar is a fairly hard cheese that will transform into a smooth-flowing cheese used for a variety of purposes when melted. As with all cheeses, a specific process is required to melt cheddar to prevent it from burning, breaking down or becoming hard and stringy, and patience is key. Always melt cheese in a double boiler to eliminate the possibility for burning it.
Choose the cheese you want to use. Though all cheddars will melt, sharp and low-fat cheddars contain less fat, milk and oils, which makes them more difficult to melt. Use a mild, high-fat cheddar cheese for the smoothest results. This will prevent the possibility of having to add milk and a flour roux to the cheese to get it to melt smoothly.
Bring the cheese to room temperature before melting. Shred with a grater. Add a few drops of lemon juice to the shredded cheese to reduce stringiness while melting.
Fill the bottom section of a double boiler with water. Place the top half of the boiler over the water. Set the range burner to low heat.
Place the shredded cheese in the top of the boiler and stir every few minutes until it starts to melt. Once it starts to melt, whisk to break down lumps until cheese is completely smooth.
Keep the cheddar cheese warm while serving to prevent it from seizing up and hardening.
Always heat cheddar and other cheeses on low settings. Heating cheese too quickly will cause the fats and oils to separate, and it will be much harder to use the melted cheese. For a creamier cheese, or to use in recipes, melt with a roux and milk mixture (bechamel). Mix one part melted butter and one part flour in a saucepan until it thickens. Keep heat low to avoid browning the roux. Add enough milk to create a soup-like texture. Continue to mix the flour and milk until it starts to thicken. Add the shredded cheese to the flour mixture and stir continually until it melts.