How to Thicken Sauce or Gravy: 4 Proven Methods That Work

Whether you're whipping up a silky béchamel or salvaging a thin gravy just before dinner, knowing how to thicken a sauce is an essential kitchen skill. From the classic roux to the quick cornstarch slurry, there are multiple ways to get that rich, velvety texture. In this post, we’ll break down four time-tested methods: roux, cornstarch slurry, beurre manié, and cream, helping you choose the right technique for every dish.

Preparing a smooth béchamel sauce with a perfectly blended roux.

Why Sauce Thickness Matters

The right sauce consistency can make or break a dish. A watery sauce can slip off your food and weakens flavor, while a thickened sauce clings beautifully and intensifies taste. Whether you’re cooking a creamy pasta, a luscious stew, or a hearty gravy, the right thickener makes all the difference.

A bowl of creamy mashed potatoes topped with rich and hearty brown gravy.

How to thicken a sauce or gravy Method 1: Roux – The French Classic

A roux is traditionally a cooked mixture of equal parts, by mass, flour and fat (usually unsalted butter). I've found that using slightly more fat (by mass) than flour creates a richer, smoother sauce. It’s the foundational thickener in classic French and Cajun cooking, and it's used in everything from macaroni and cheese to gumbo.

Stirring a smooth roux in a stainless steel pan, preparing the base for a rich and flavorful sauce.

How to Make a Roux:

1. Melt 2 tablespoons of unsalted butter (28g) in a saucepan over medium heat.

2. Add 2 tablespoons of all-purpose flour (16g).

3. Whisk continuously for 2–5 minutes until the mixture gives off a warm nutty smell. For a darker roux (used in Cajun dishes), cook longer until deep brown.

Sauce Thickness Guide (Per 1 Cup / 250ml of Dairy):

• Thin Sauce: 1 Tbsp Butter (14g) + 1 Tbsp (8g) Flour

• Medium Sauce: 1.5 Tbsp Butter (21g) + 1.5 Tbsp (12g) Flour

• Thick Sauce: 3–4 Tbsp Butter (42-56g) + 3–4 Tbsp (24-32g) Flour

Preparing a classic roux by adding flour to melted butter in a stainless steel pan.

When to Use:

Use roux when making sauces like béchamel, velouté, or cheese sauce. It works best when added early in the cooking process and allowed to simmer with the liquid.

How to thicken a sauce or gravy Method 2: Cornstarch Slurry – Quick and Gluten-Free

A cornstarch slurry is the fastest way to thicken a sauce, and it's naturally gluten-free.

Preparing a cornstarch slurry, with cornstarch measured in a small bowl and water ready for mixing.

How to Make a Cornstarch Slurry:

1. Mix 1 tablespoon of cornstarch with 1 tablespoon of cold water until fully dissolved.

2. Stir the slurry into your simmering sauce.

3. Cook for 1–2 minutes until the sauce thickens. Avoid boiling too long as cornstarch can break down.

Cornstarch Amounts for 1 Cup / 250ml of Sauce or Gravy:

• Thin Sauce: 0.5 Tbsp (3.75g)

• Medium Sauce: 1 Tbsp (7.5g)

• Thick Sauce: 1.5 Tbsp (11.25g)

When to Use:

Great for gravies, stir-fry sauces, or pan sauces that need quick thickening just before serving.

Salisbury steak meatballs simmered in a rich, cornstarch-thickened gravy with mushrooms, served over creamy mashed potatoes.

How to thicken a sauce or gravy Method 3: Beurre Manié – Butter + Flour Magic

Beurre manié (pronounced "burr man-YAY") means “kneaded butter” in French. It’s similar to a roux but is uncooked, making it perfect for last-minute thickening.

Mixing flour and butter to create a smooth beurre manié, a classic thickening agent for sauces and soups.

How to Make Beurre Manié:

1. Mix equal parts of softened unsalted butter and flour (e.g., 2 tablespoons each) until it forms a smooth paste.

2. Whisk the paste into your hot sauce a bit at a time.

3. Simmer gently until the sauce thickens and the flour cooks out.

When to Use:

Ideal for thickening pan sauces, soups, or gravies at the end of cooking. It gives a glossy finish and rich mouthfeel.

How to thicken a sauce or gravy Method 4: Heavy Cream – Rich and Simple

Cream doesn’t just add richness—it can also thicken sauces naturally as it reduces.

Pouring cream into a simmering sauce to create a rich, thick and creamy texture.

How to Thicken with Cream:

1. Add ½ cup to 1 cup of cream (also called heavy cream, whipping cream, or double cream) to your sauce.

2. Simmer uncovered over medium heat, stirring occasionally.

3. Cook until the cream reduces and thickens to your desired consistency.

When to Use:

Perfect for cream sauces, Alfredo, or recipes where added richness is welcome. This method is naturally gluten-free and adds luxurious texture.

Serving up a deliciously rich and creamy homemade Alfredo pasta straight from the pan, ready to enjoy.

Tips for Choosing the Right Thickener

• Use roux for deep flavor and base sauces.

• Choose cornstarch slurry for speed and gluten-free needs.

• Try beurre manié for a glossy finish and last-minute fixes.

• Use cream when you want added richness and smoothness.

Pouring rich homemade cream of mushroom sauce over fresh green beans for a classic casserole delight.

Bonus Tip:

Avoid over-thickening! Always add your thickener gradually and let the sauce simmer to gauge its final texture.

Final Thoughts

Mastering these four sauce-thickening methods—roux, cornstarch slurry, beurre manié, and heavy cream—can elevate your cooking from average to exceptional. Each technique has its ideal use, and knowing when and how to apply them makes all the difference in the kitchen. Next time your sauce or gravy is looking a little thin, reach for one of these tried-and-true methods and turn it into a showstopper.

Explore the Made Simply cookbook series from The Sauce and Gravy Channel to elevate your homemade sauces, gravies, and comfort food creations.