Quick answer: For thickening sauces or fillings, 2 tablespoons all-purpose flour can replace 1 tablespoon cornstarch as a practical starting point. Arrowroot, tapioca, and potato starch can also work, but the best ratio and cooking method depend on whether you need a sauce thickener, pie filling, custard, cookie tenderizer, or crisp coating.
Need a quick ratio? See our focused cornstarch substitute chart for thickening, fillings, baking, and coatings.
Thickening: Cornstarch granules absorb water and swell dramatically when heated, creating a thick gel. It's twice as powerful as flour as a thickener — 1 tbsp cornstarch = 2 tbsp flour for equivalent thickening. It produces a clear, shiny gel (unlike the cloudy gel flour produces), making it preferred in fruit pie fillings and Asian sauces.
Tenderizing in baking: Mixed into flour (as in the DIY cake flour substitute), cornstarch dilutes protein content, producing more tender, fine-crumbed cakes and cookies. It literally interrupts gluten formation.
Coating for frying: Creates an extremely crispy, light crust — more so than flour because starch gelatinizes and crisps more thoroughly than protein-containing flour.
Stabilizing: Added to powdered sugar (confectioners' sugar contains 3% cornstarch) to prevent caking and stabilize frostings.
Use 2 tsp arrowroot per 1 tbsp cornstarch. Arrowroot thickens at a lower temperature than cornstarch (important for custards and sauces you don't want to boil) and produces a clearer, glossier gel. Best for: fruit sauces, glazes, clear gravies, and delicate custards. Doesn't work well in acidic mixtures (sauces with lemon or tomato) — loses thickening power.
The most widely available substitute. Use double the volume. Flour thickens by gelatinizing starch AND coagulating proteins — the result is a cloudier, less silky sauce. Must be cooked for at least 1–2 minutes to eliminate raw flour taste. Works for: gravies, béchamel-style sauces, casserole fillings. Not for: crystal-clear gels or fresh fruit pie fillings where clarity matters.
Use equal volume (1:1). Tapioca thickens quickly, produces an extremely clear gel, and stays stable when frozen and reheated (cornstarch breaks down and weeps after freezing). Best for: fruit pie fillings that will be frozen, Asian-style sauces, and clear glazes. In high heat applications, tapioca can become slightly stringy — combine with another starch for best results.
Use 1:1 by volume. Very similar to cornstarch in thickening power with a clear result. Works well in sauces and gravies. Becomes gluey if overcooked — add toward the end of cooking and don't boil.
Use 2 tbsp per 1 tbsp cornstarch for thickening. Produces a slightly less clear result. Gluten-free. Good in Asian-style soups and for coating in crispy frying applications.
Cornstarch's role here is to dilute protein content — use 2 tbsp cornstarch per cup of flour removed (so replace 2 tbsp of all-purpose flour with 2 tbsp cornstarch). This is the classic DIY cake flour method.
Arrowroot powder works as a 1:1 substitute in this application. Potato starch also works. Both produce a similar tenderizing effect.
1–2 tbsp of cornstarch in shortbread produces the melt-in-your-mouth texture. Arrowroot is the best substitute (1:1). Potato starch works slightly less well but is acceptable.
Cornstarch thickens pastry cream and sets its structure. Arrowroot is the best substitute — use equal amounts and note it thickens at lower temperature (don't overheat). All-purpose flour works 1:1 but produces a heavier, cloudier result. The classic French preparation (crème pâtissière) traditionally uses all-purpose flour.
Use 1:1. Rice flour produces an even crispier coating than cornstarch in many frying applications. The starch gelatinizes to form an extra-thin, crackly crust. Preferred in Korean fried chicken and many Japanese applications.
Works well as a coating and produces a light, crispy result. Slightly less crispy than cornstarch but very comparable.
Good coating substitute. Produces a very crispy, slightly chewy crust similar to Korean fried chicken style.
💡 For the crispiest fried coating, use a mix of 1/2 rice flour + 1/2 cornstarch (or arrowroot). The combination produces more consistent crispiness than either alone.
| Application | Best Substitute | Ratio | Notes |
|---|---|---|---|
| Sauce/gravy thickening | Arrowroot powder | Start near 1:1; adjust as needed | Clear gloss; avoid prolonged high heat and note dairy can affect texture |
| Sauce/gravy thickening | All-purpose flour | 2 tbsp per 1 tbsp cornstarch | Cloudier; cook out raw taste |
| Fruit pie filling | Tapioca starch | 1:1 | Freezes well; stays clear |
| Cake flour / tenderizing | Arrowroot powder | Recipe-dependent | Not a universal replacement for cornstarch in homemade cake-flour formulas |
| Shortbread texture | Arrowroot or potato starch | 1:1 | Similar melt-in-mouth effect |
| Frying coating | Rice flour | 1:1 | Even crispier than cornstarch |
| Custard/pastry cream | Arrowroot | Recipe-dependent | Dairy and reheating can affect arrowroot texture; use a tested formula |
