Sauce and Mixture Preparation

15 min Beginner Şef Aylin Demir

Roux: The Classic Sauce Thickener

Roux is a classic thickener made by cooking equal measures of butter and flour together. White roux (cooked for 1-2 minutes) is used for milk-based béchamel sauce; blond roux (5-6 minutes) is used for sauces that need a deeper flavor; and brown roux (10-15 minutes), which has less thickening power but gives dark sauces a toasted hazelnut aroma, is used for those sauces.

To prevent lumps, add the liquid to the roux a little at a time—not the roux to hot liquid. Stir thoroughly with each addition, and do not add the next portion until the liquid has fully combined with the roux.

If you want a starch-based thickener (such as cornstarch), first mix it with cold water in a separate bowl until smooth, then add it to the boiling liquid; dry starch added directly to hot liquid clumps immediately.

Emulsions: Holding Oil and Water Together

Mixtures such as mayonnaise and classic salad dressing are emulsions that hold together oil and water-based liquids (lemon juice, vinegar), which normally do not mix. Lecithin in egg yolk is a natural emulsifier that binds these two substances together. For sauces that stay raw, such as mayonnaise, and when rescuing a broken sauce, use pasteurized egg yolk; pregnant women, young children, older adults, and people with weakened immune systems should not eat sauces made with raw egg.

To make an emulsion, add the oil a little at a time in a thin stream while whisking continuously; if the oil is poured in all at once, the mixture “breaks,” meaning the oil and water separate again.

If an emulsion breaks, do not panic: take a small amount of fresh egg yolk or water, then slowly whisk the broken mixture into this new base to bring it back together.

Reduction: Thickening by Simmering

Reduction is the process of thickening a liquid (wine, stock, cream) by boiling it uncovered to evaporate water; as the water evaporates, the flavor concentrates. When one liter of wine is reduced to about 200-250 milliliters, it becomes noticeably thicker and sweeter.

Adding salt early during reduction can be risky; as the liquid decreases, the salt becomes more concentrated and the sauce may end up too salty. It is safer to season with salt after the reduction is complete.

Risk of Curdling in Cream- and Yogurt-Based Sauces

Cream can boil at high heat without a problem, while lower-fat dairy products such as yogurt and milk tend to curdle with sudden temperature changes. Before adding a yogurt-based sauce to a hot dish, slowly warm it with a spoonful of hot liquid (tempering) to prevent the yogurt from curdling from thermal shock.

Mixing a small amount of flour or starch into yogurt-based sauces reduces the risk of curdling, stabilizes the proteins, and makes them more resistant to high heat; this method is used especially in yogurt soups.

Balance the Flavor When Seasoning a Sauce

When a sauce tastes bland, the first impulse is to add salt, but often what is missing is acidity or sweetness. A small amount of lemon juice or vinegar can add depth to a sauce, while a pinch of sugar can soften the sharpness of an overly acidic or tomato-based sauce.

Technique

Technique Step by Step

Cook the Roux

6 min

Cook equal measures of butter and flour for 1-15 minutes, depending on the color you want.

Done right: The roux has reached the intended color (white, blond, or brown).

Common mistake: Cooking the roux for too short a time leaves a raw-flour taste in the sauce.

Add the Liquid Gradually

4 min

Add the hot liquid to the roux in small amounts, mixing thoroughly each time.

Done right: The mixture has reached a smooth, lump-free consistency.

Common mistake: Pouring in the liquid all at once causes lumps.

Build the Emulsion

5 min

Add the oil a little at a time in a thin stream while whisking continuously.

Done right: The mixture has become a smooth, thick emulsion.

Common mistake: Pouring in the oil all at once causes the mixture to break (separate).

Make a Reduction

15 min

Boil the liquid uncovered until its volume has reduced to about one-quarter.

Done right: The liquid has become noticeably thicker and sweeter.

Common mistake: Adding salt at the start of reduction can leave the sauce too salty.

Temper the Yogurt

3 min

Before adding the yogurt-based sauce to a hot dish, warm it slowly with a spoonful of hot liquid.

Done right: The yogurt remains smooth and does not curdle when mixed into the sauce.

Common mistake: Adding yogurt directly to boiling liquid causes it to curdle.

Check

What Does Done Right Look Like?

TemperatureThe yogurt-based sauce has been tempered and warmed gradually before being added to the hot dish, without sudden temperature shock.

Color

The roux stays the intended color (white, blond, or brown); a nearly black color means it has burned.

Aroma

Brown roux gives off a toasted hazelnut aroma; a sharp burnt smell indicates the heat is too high.

Sound

During reduction, the liquid boils with a distinct bubbling sound; a quieter sound indicates that much of the water has evaporated.

Texture

A finished emulsion is smooth and uniform, with no visible oil droplets.

Consistency

A thickened sauce is consistent enough to coat the back of a spoon in a thin layer.

Watch Out

Common Mistakes

Pouring Hot Liquid into Roux All at Once

Why it happens: The sudden temperature difference and rapid mixing cause lumps.

How to prevent it: Add the liquid a little at a time, mixing thoroughly each time.

How to fix it: Break up the lumpy parts with a whisk.

Adding Oil Too Quickly When Making an Emulsion

Why it happens: The oil and water components separate, and the mixture breaks.

How to prevent it: Add the oil in a thin stream while whisking continuously.

How to fix it: Take a small amount of fresh egg yolk and slowly whisk the broken mixture into this new base.

Adding Salt at the Start of Reduction

Why it happens: As the liquid decreases, the salt becomes more concentrated and the sauce may end up too salty.

How to prevent it: Add the salt after the reduction is complete.

How to fix it: Taste again after the reduction is finished and adjust the salt.

Adding Yogurt Directly to Hot Liquid

Why it happens: Sudden thermal shock can cause the yogurt proteins to separate and the yogurt to curdle.

How to prevent it: Temper the yogurt with a spoonful of hot liquid before adding it.

How to fix it: Try straining the curdled sauce and slowly combining it again with a spoonful of cold yogurt.

Practice

Practice Task

Prepare Béchamel Sauce

Cook a white roux, then add the milk a little at a time to make a smooth béchamel sauce.