Stir, stir and stir again
We hope those biceps are ready for a workout, because béchamel sauce requires constant stirring. Stir the butter as it melts, stir in the flour until it forms a roux, whisk as you add the milk, and then whisk some more. Make sure to move the whisk around the entire pan, too, whisking around the sides and across the base to stop the sauce from catching.
Go easy on the heat
The secret to making good sauce is to go slowly, so all the ingredients combine gradually and smoothly. If you turn the heat up too high, the mixture will be cooked through before it has properly combined, and something is likely to burn. You also run the risk of the sauce curdling or splitting, which happens when the proteins separate from the milk to form curds. For best results, cook the roux over a low heat and increase to medium when adding the milk.
Use quality ingredients
It seems obvious, but good ingredients make a good sauce, so opt for quality milk and butter. For the ultimate creamy flavour, use full-cream milk and a European-style butter with higher butterfat and lower moisture. If you’re watching the calories, you can substitute semi-skimmed milk, but don’t be tempted to use low-fat butter substitutes, as fat is necessary for making the roux.
Use the correct ratio of flour and butter
When making your roux, it’s important to get the right proportion of flour and butter. Too much flour and it can burn or turn out lumpy. Too much butter and your sauce will be weak and runny. The correct ratio is equal parts butter and flour, which is pretty easy to remember, but get out your measuring scales rather than trying to guess - 2oz of flour won’t look the same as 2oz of butter if you’re doing it by eye. When it comes to adding the milk, you can adjust the amount according to how thick you want the sauce, but the ratio of flour to butter should always remain the same.
Cut the butter into cubes
This is a simple way of preventing the butter from burning. If you put the butter into the pan in one lump, it won’t all be heated at the same rate, and the bottom is likely to have burned before the top has begun to melt. By cutting it into small cubes, you can make sure that all of the butter receives an equal amount of heat and melts in a uniform way.
Get your timing right
Cooking the roux just right is a tricky task. It needs to be cooked to form what is known as a white, or blond roux. This means that you should stop cooking the butter and flour before it starts to brown - brown roux can be used to make other sauces, but it’s not the flavour we’re going for here, and it won’t thicken the sauce so well. On the other hand, you also need to make sure you don’t undercook the roux, as this will give your sauce a chalky, raw flour taste. The best way to judge when your roux is done is by smell and taste. After about 3-5 minutes, the mixture should start smelling a little like cookie dough. At this point, try tasting some. If it still tastes of raw flour, keep cooking. If it doesn’t, you’re ready to start adding milk.
Warm up your milk
This isn’t strictly necessary, but cold milk will spit as it hits the pan, making a mess, and it also means your sauce will take longer to cook. While this may sound like a small thing, a tricky dish like béchamel requires constant supervision, and prolonging the process unnecessarily increases the odds of you losing concentration and something going wrong. Some people like to boil the milk in a separate pan on the stove, but two minutes in the microwave should do it.
Add the milk slowly
If you add the milk all at once, the roux will clump together in little lumps at the bottom of the pan and it will be difficult to whisk them all out. The trick is to pour the milk in a little at a time, whisking the mixture as smooth as possible before adding the next drop.
Make sure you cook the sauce for long enough
Once you’ve finished adding the milk, the sauce will start to thicken fairly quickly, but it’s not ready until it’s thick enough to coat the back of a spoon. If you’re not sure, dip a spoon into the sauce. If the béchamel is properly thickened, it should stay on the back of the spoon. To be doubly sure, draw your finger across the coated spoon and watch what happens. If your finger clears a path on the back of the spoon, the sauce is thick enough, but if it runs back in to the fill the space, it needs a little longer.
Make a béchamel sauce that’s good for everyone
Some of the ingredients in regular béchamel sauce aren’t suitable for everyone. Coeliacs and people with gluten intolerance can’t eat flour, while milk and butter are not suitable for vegans. Luckily, there are substitutes for all three of these ingredients, so you can make a béchamel sauce that everyone can enjoy. To make your sauce gluten-free, swap your regular wheat flour for a mixture of four parts potato starch to three parts cornflour.
