🥄 Cornstarch vs Flour for Thickening: What’s the Best Choice?
When it comes to thickening soups, sauces, gravies, or pie fillings, two ingredients always come up: cornstarch and flour. But which one should you use, and when? In this guide, we’ll dive into cornstarch vs flour for thickening, so you’ll always get the perfect consistency — whether you’re making a silky custard or hearty stew.
If you’re curious about other ingredient swaps, don’t miss our guide on Brown Sugar vs White Sugar — because every detail counts in your kitchen magic.
🌽 What Is Cornstarch?
Cornstarch is a fine, white powder made from the starchy part of corn kernels. It’s a pure starch, meaning it thickens quickly and gives a smooth, glossy finish to liquids.
🔹 Best For:
- Sauces
- Gravies
- Fruit pie fillings
- Puddings and custards
Cornstarch is gluten-free and ideal when you want a clear, shiny sauce (think sweet and sour sauce or lemon glaze). But it doesn’t hold up well to long cooking or acidic ingredients — it can break down and lose its thickening power.
🌾 What Is Flour?
Flour (usually all-purpose flour) is made by grinding wheat into a fine powder. It contains starch and protein, and is a common thickener in cooking and baking. Unlike cornstarch, it creates a cloudier, more matte texture.
🔹 Best For:
- Stews
- Roux-based sauces (like béchamel)
- Creamy soups and gravies
Flour needs to be cooked longer to eliminate its raw taste. You usually start by making a roux (cooking it in fat like butter or oil) before adding liquid. It’s great for hearty, rich textures.
⚖️ Cornstarch vs Flour: Side-by-Side Comparison
| Feature | Cornstarch | Flour |
|---|---|---|
| Source | Corn (gluten-free) | Wheat (contains gluten) |
| Thickening Power | Strong – use 1 tbsp | Weaker – use 2 tbsp |
| Texture | Silky, glossy | Thick, creamy |
| Best For | Pies, sauces, desserts | Soups, stews, gravies |
| Taste | Neutral | Slight wheat taste unless cooked |
| Appearance | Clear and shiny | Cloudy and matte |
| Cooking Time | Thickens fast, low heat | Needs more time, high heat OK |
🧑🍳 Can You Substitute Cornstarch for Flour?
Yes — but you’ll need to adjust the amount. Cornstarch is more powerful, so use half the amount of cornstarch if you’re replacing flour. For example:
Replace 2 tbsp of flour with 1 tbsp of cornstarch.
Remember: cornstarch works best with low to medium heat and should be added as a slurry (mixed with cold water first) to avoid clumps.
If you’re into substitutions, check out our guide on Sea Salt vs Table Salt for flavor differences that matter.
💡 Final Thoughts: Which Should You Use?
Choose cornstarch when you want:
- A smooth, shiny finish
- Gluten-free options
- Quick thickening for desserts or sauces
Choose flour when you want:
- Rich, hearty textures
- Better stability in long cooking
- Classic gravies, soups, or roux-based sauces
Both work beautifully — it just depends on the dish. 🎯