01
All-Purpose Flour
10.02 tbsp : 1 tbsp
Use 2 tbsp flour per 1 tbsp cornstarch; thickens sauces but gives cloudier, less glossy result
10.0
cornstarch substitutes
11 substitutes · avg score 5.6 · Pure starch extracted from corn kernels, producing a silky, glossy thickener for sauces, pie fillings, and custards. Also used in shortbread and as a crisping agent in coatings.
clarity, gloss, and a low tolerance for heat
Cornstarch is the pure starch fraction of corn, with the protein, fat and fibre stripped away — which is exactly why it behaves the way it does. Whisked into cold liquid and then heated, the granules swell and burst and the liquid sets into something silky and see-through. A flour-thickened gravy is opaque and slightly floury; a cornstarch-thickened one is glossy and lets colour through. That difference is the whole reason cornstarch exists in a pantry that already has flour in it.
It has two well-known limits. It weakens with prolonged boiling, so a sauce thickened early in a long simmer will loosen again by the end. And it does not survive freezing and thawing gracefully — a frozen pie filling thickened with cornstarch tends to weep. Neither is a defect so much as a scheduling instruction: add it late, cook it just until it thickens, and stop.
So when you substitute, you are trading along three axes: how clear the result is, how much heat it will take, and how much of it you need. The list below spreads across all three, and the ratios move quite a lot — some entries want half the amount, some want double.
choosing
match the finish you need
If the sauce should stay glossy and clear, arrowroot is the closest relative. It scores 10.0 as arrowroot flour and 6.7 under its own name, both at a straight 1:1, and the notes agree on the character: a glossy finish like cornstarch, with better freezer stability, and the same warning to keep it off a long boil. It is the best pick for a fruit sauce, a glaze, or anything going into the freezer. Tapioca at 6.7 is the pie-filling specialist — use 2 tbsp per 1 tbsp of cornstarch and expect a glossy, slightly stretchy set that suits berries particularly well.
If clarity does not matter, flour is the workhorse and the ratio is the thing to remember: 2 tbsp of flour per 1 tbsp of cornstarch, scoring 10.0. You get a cloudier, less glossy sauce, and in exchange it holds up to far more cooking — which is why a roux-based gravy can simmer for half an hour and a cornstarch one cannot. Rice flour, also 10.0, is the gluten-free version of the same trade at the same doubled quantity, with a slightly less smooth finish.
Potato flour at 5.0 goes the other way and is used at half the quantity, which makes it easy to overshoot. For a stew rather than a sauce, grated raw potato at 3.3 is a genuinely old technique — it thickens as the starch cooks out and leaves a rustic, starchy body. The note draws the line correctly: soups yes, clear sauces no.
Two entries thicken by a different mechanism and are worth knowing for cold applications. Ground chia at 3.3 and ground flaxseed both form a gel with liquid rather than gelatinising with heat, which makes them useful in puddings, jams and baked goods and unsuitable for anything that needs to look clean. And read the last entry as a boundary marker: baking powder is not a thickener at all, and only appears here because cornstarch is occasionally used in cakes for lightness rather than for thickening. If that was the job, this is the entry; for a sauce, it does nothing.
convert cornstarch measurements
quick swaps (averaged across uses)
02
Arrowroot Flour
10.01 tbsp : 1 tbsp
Same as arrowroot; 1:1 swap for thickening, freezes better than cornstarch but don't boil long
10.0
03
Rice Flour
10.02 tbsp : 1 tbsp
Use double; less smooth finish
10.0
04
Arrowroot
6.71 tbsp : 1 tbsp
Use 1:1; arrowroot gives glossy finish like cornstarch, breaks down with prolonged heat
6.7
05
Cake Flour
6.71 tbsp : 2 tbsp
Contains cornstarch already; use for dusting or dredging, not as pure thickener in sauces
6.7
06
Tapioca
6.72 tbsp : 1 tbsp
Use 2 tbsp tapioca per 1 tbsp cornstarch; gives glossy thickening for pie fillings and fruit sauces
6.7