Starches & Slurry’s

This article is about making a slurry with either cornstarch, arrowroot powder, or tapioca starch.

What is a slurry

Slurry’s are made by combining a little bit of water with a starch powder. This slurry is added to a hot mixture to thicken it. Although cornstarch is popular, arrowroot powder and tapioca starch can be used the same way. The slurry technique is the same, however the starches are not equal.


  • Is a great thickener, if you don’t want to freeze it. Sauces made with cornstarch will turn spongy when thawed.
  • Needs to come to full boil.
  • Thickening power breaks down when cooking acidic fruit sauces like lemons, oranges and pineapple.

Arrowroot Powder

  • Arrowroot powder also goes under the name of arrowroot flour.
  • Arrowroot powder is the most neutral flavor of all the starches.
  • It thickens quickly, once mixture has thickened and cooked briefly, remove it from its heat source. Over cooked arrowroot powder will break down and go watery.
  • Works well acidic liquids.
  • Is freezer friendly.

Tapioca Starch

  • Known for glossy sheen in Asian cooking/stir-fry’s
  • Loses it thickening power when thickening an acidic liquid.
  • Tapioca starch is heat stable for a long time while arrowroot powder will break down when overcooked.
  • Is freezer friendly.


How to make a slurry

  • Stir together an equal amount of water and starch. Mix until there are no lumps.
  • Add slurry to what you want to thicken, but first bring that mixture to boil.
  • When adding the slurry, be prepared to stir and continue stirring until the mixture comes back to boil. In the process the mixture will have thickened.
  • Note, the mixture will turn cloudy and will turn somewhat clear as it thickens. This is normal.

In general, how much to use

  • 1 Tbsp starch per cup of liquid will give a thin to medium consistency. As a reference a thin sauce would be similar to the consistency of a salad dressing like this Italian Dressing. 
  • 2 Tbsp per cup of liquid will give you a gravy like consistency
  • Starch can also be used to make a Fruit & Berry Topping