All About Starches

By: Whitney Barnes | July 6 2018

Starches are incredibly versatile ingredients to have on hand and are particularly useful both as thickeners and in gluten free baking. Here at Bob’s Red Mill we carry different types of starches that cater to different food allergies or diets. Cornstarch is the most widely recognized, but for those looking for a corn-alternate we also have Arrowroot Starch, Tapioca Starch, Potato Starch, and Sweet White Rice Flour which though technically not a starch can be used like one in practice.

But … what do starches do?

Generally, when starches are added to liquids they absorb water. As they’re heated, the tiny starch granules swell and then burst, emptying more starch molecules into the liquid causing it to thicken. In gluten free baking, the starch molecules help to bind ingredients together, adding moisture and texture to your gluten free baked goods.

Starches and starchy flours (like Sweet White Rice) are usually used in a smaller ratio than heavier flours in gluten free flour blends. This is because adding too much starch granules can cause your baked goods to be gummy - it’s important to find a good balance. Starches can also be used as a coating for frying as an alternative to wheat flour.

How do I use a starch to thicken my recipe?

To thicken liquids with starches, you will first need to make a slurry which is similar to a roux, but is added at the end of the cooking process rather than the beginning. Adding raw starch directly to liquids will cause the starch to form clumps - not what we’re going for.

To make a slurry, combine your starch with an equal amount of cool or tepid water and stir to dissolve into a pourable liquid. Slowly pour the slurry into the main liquid to be thickened (this liquid should be warm to start) and stir or whisk constantly over even heat until the liquid has thickened. Some starches cannot tolerate boiling or cooking for long periods of time, or may not work with acidic ingredients, so be aware of the properties of the starch that you are working with - see below!

Cornstarch, Tapioca Starch, Arrowroot Starch, Potato Starch

Cornstarch

Cornstarch is made from the starchy endosperm of corn and has long been used as a thickener for sauces, custards, and gravies. Bob’s Red Mill Cornstarch is made from Non-GMO corn. If your recipe calls for wheat flour as a thickener, you can use half the amount of corn starch as a substitution - it’s a pretty “strong” thickener. In gluten free baking, Corn starch can be used to add softness to gluten free baked goods like pancakes and muffins and is great when used in combination with Tapioca Starch.

  • Has a neutral flavor but can leave a chalky, starchy flavor if not cooked long enough
  • Should be mixed into a slurry before thickening liquid
  • Can withstand low-moderate heat but will break down and lose its ability to bind in long, temperature cooking or freezing
  • Does not work well with acidic ingredients
  • Adds an opaque quality to sauces

Try it in this recipe for Boston Cream Pie Cookies!

Tapioca Starch

Tapioca Starch, also called Tapioca Flour, is made from the starchy tuberous root of the cassava plant. To make tapioca flour from cassava, the tubers are first peeled to remove the stem, excess soil, and skin. The peeled cassava is then thoroughly washed, chopped, and finely grated into a pulp. Water and the cassava pulp are then put into a hydrocyclone where they are spun to extract the starch and separate the fibrous pulp. The resulting starch liquid is then dried into our tapioca flour.  

  • Has a neutral flavor and provides chew, elasticity, and structure in gluten free baking
  • Will help baked goods develop a golden brown crust
  • Can cause baked goods to be a big tough/dry, so ensure your recipe has enough liquid to balance
  • Should be mixed into a slurry before thickening liquid
  • Adds a shiny gloss to sauces
  • Can replace Cornstarch in a 3:4 ratio (3 tbsp Cornstarch = 4 tbsp Tapioca Starch)

Try it in this recipe for Honey Blackberry Pie!

Arrowroot Starch

Arrowroot Starch, also called Arrowroot Flour, is derived from the rhizomes of an herbaceous perennial found in tropical climates. The starch is extracted from the rhizomes that are washed, pulped, pressed and dried, then ground into a fine, white, powdery starch. It can be used as the starch component in gluten free flour blends and works very well as a thickener.

  • Has a neutral flavor and can replace cornstarch one for one to thicken sauces, stews, and soups
  • Should be mixed into a slurry before thickening liquid
  • Can withstand low-moderate heat but will break down and lose its ability to bind in long, high temperature cooking
  • Works well with acidic ingredients (like in your lemon curd!) but not in milk-based cream sauces as it may cause curdling
  • Adds a shiny gloss to sauces
  • Can replace Cornstarch in a 1:1 ratio

Try it in this recipe for Roasted Blueberry Ice Cream!

Potato Starch

Potato Starch is made from a variety of potato that has a very high starch content. After grinding the potatoes and separating the water from the potato pulp, the starch is extracted out of the potato pulp with tap water. It is then dried to a powder. It is naturally white in color and not bleached in any way. Potato Starch is not the same as Potato Flour - Potato Flour is made from dried and ground Russet Potatoes and has a very strong potato flavor.

  • Has a neutral flavor and provides a balance of structure and tenderness in gluten free baked goods
  • Can replace 1 Tbsp cornstarch using 1 3/4 Tbsp Potato Starch
  • Should be mixed into a slurry before thickening liquid
  • Can withstand low-moderate heat but will break down eventually in boiling liquid
  • Cannot be used where your recipe calls for Potato Flour

Try it in this recipe for Orange Almond Flour Cake!

Sweet White Rice Flour

Though not a pure starch, Sweet White Rice Flour can be used in a similar manner in baking and cooking. It is made from a very starchy white rice also called “glutinous” rice although it does not contain gluten. Sweet White Rice Flour isn’t actually sweet either, but it is much starchier than White Rice Flour - talk about misnomer! Because of its starchiness, Sweet White Rice Flour is an effective binder and is often used in a similar manner to starches.

  • Has a neutral rice-like flavor
  • Can replace wheat flour in a 1:1 ratio for thickening
  • Cannot be used as a replacement for White Rice Flour
  • Holds up well to high heat
  • Acts as a strong binder in gluten free baked goods

Try it in this recipe for Marbled Red Bean Cake!

Whew, that’s a lot of information to take in. Use this as a guide when you’re looking to replace Cornstarch in a recipe or just looking to experiment! Generally these starches all perform the same task but each has their own unique properties.

28 Comments

  1. fran
    Can you come up with a dry almond milk product that I can just add water to. So many times I run out before shopping day. I use your almond flour with water now but it has a bit of a gritty feel to it.
    Also can I add tapioca starch to the almond milk to thicken it up a little ? Does tapioca have to be cooked to be eaten?
    Reply
    1. Whitney Barnes
      Hi Fran, thanks for your feedback - we'll pass that along to our team here. If you have a high powdered blender you should be able to attain a smooth (not gritty) texture with almond milk, but if not you can always pass the almond milk through a mesh sieve or cheesecloth to strain out the larger particles. Tapioca Starch needs to be heated to "activate" the thickening properties, adding it to cold liquid without heating will not thicken very much aside from the small amount due to absorption.
      Reply
  2. Dana
    Hi, my son is allergic to potatoes. Which starch can be used to replace potato starch? Thanks
    Reply
    1. Whitney Barnes
      Hi Dana, you could use any of the starches listed in this article to replace potato starch. Note that to replace 1 Tbsp cornstarch use 1 3/4 Tbsp Potato Starch.
      Reply
  3. Effy Fred
    Is there any substitute for glutinous rice flour.?
    Reply
    1. Whitney Barnes
      Whitney Barnes
      Hi Effy - it really depends on what you're making. If it's a recipe that specifically calls for Glutinous Rice Flour and/or Sweet White Rice Flour then the success of the recipe may depend on that single ingredient. Our Customer Service team is happy to talk through and trouble shoot recipes if needed. They can be reached at 1-800-349-2173 or [email protected]
      Reply
  4. vonmoishe
    I guess it was just bad luck that I found this site in my search results and trusted it. I needed to replace tapioca starch with what I had on hand: potato starch. Based on the ratios above, 12 Tb cornstarch = 16 Tb tapioca starch, and 12 Tb cornstarch = 21 Tb potato starch. Therefore, your guidance is that I needed 21 Tb of potato starch for every 16 Tb of tapioca starch I was replacing. This is so wrong. I ended up with a fruit dessert that set into a gummy bear-like texture. Further online research, just about everywhere else, confirmed that you usually need less potato starch by volume than the amount of tapioca starch you're replacing. Please take the time to update your site and correct the misinformation.
    Reply
  5. Fay
    What is flower corn starch and where to purchase it thanks
    Reply
    1. Whitney Barnes
      Hi Fay, here's a link to our Corn Starch. Click on "Find a Store" and enter your zip code to find stores in your area carrying our products! :)

      Bob's Red Mill: Corn Starch
      Reply
  6. rebecca
    Hi!
    I was reading that RAW potato starch has a really low glycemic index. I see that your potato starch is UNMODIFIED, is that the same things as RAW?
    Reply
    1. Whitney Barnes
      Whitney Barnes
      Hi Rebecca - No, our Potato Starch is not considered raw. It is heated during the drying process.
      Reply
  7. Abigail Mcelroy
    Abigail Mcelroy
    Which one works best to replace cornstarch in a gravy ? I tend to get digestive issues from cornstarch when I use it for a clear gravy. I don't have this problem with wheat flour. But sometimes you need a clearer gravy instead of opaque. Which starch would work better. Thanks in advance. Abby.
    Reply
    1. Whitney Barnes
      Whitney Barnes
      Hi Abigail - I would recommend Tapioca Starch as a replacement.
      Reply
  8. Hexx
    Hi Whitney - which of these starches would you recommend as a binder for vegan burgers?
    Reply
    1. Whitney Barnes
      Whitney Barnes
      Hi Hexx - I would recommend experimenting with Tapioca or Potato Starch. Both absorb liquid well and have a neutral flavor.
      Reply
  9. Elisa
    Do you carry wheat starch? I am looking for one made from domestically grown wheat.
    Reply
    1. Whitney Barnes
      Whitney Barnes
      Hi Elisa, no that's not something we carry.
      Reply
  10. John Hackney
    There is serious typo in this article. When substituting potato starch for cornstarch, the usual practice is to use less potato starch that cornstarch, usually about 1/2 as much. Many, many websites recommend a 1 for 1 substitution, but that is too much, leading to pasty puddings and sauces. This article says 1 3/4 times the amount of cornstarch, which is hopelessly incorrect. Perhaps the intent was to write 3/4, without the 1.
    Reply
  11. megan
    I see that most starches are only good for low to moderate heat or break down in long heat times, what is low to moderate heat for baking? how long is too long before it breaks down? why would a recipe call for multiple starches any idea?
    Reply
    1. Whitney Barnes
      Hi Megan! If you're baking muffins or a cake you shouldn't need to worry about the starches breaking down. It's only under certain circumstances that the starches would reach a breaking point—maybe something like simmering a sauce in the slow cooker for 24 hours.

      Different starches provide differing textures/attributes in gluten free baked goods. It's not uncommon to see a mixture of multiple starches (or starchy flours) mixed together to create a specific texture.
      Reply
  12. Lari Bain
    Regarding starch to thicken fruit juice when making gelo/pudding, which would give the best clarity? I've found cornstarch to muddle colors and add opacity...not what I want!
    Reply
  13. Laurie
    I am allergic to potato and therefore use alternatives. My question is do you use the same equipment to process all the different starches and is there cross contamination?
    Reply
    1. Whitney Barnes
      Hi Laurie, we do clean the lines in between production runs. However, as potato is not a top allergen we do not test for its presence in other items. If you have more questions, our Customer Service team can help. Reach them at [email protected]
      Reply
  14. Lynn Morin
    Can I use white rice flour instead rice starch?
    Reply
  15. Deb Bendit
    I’m modifying a recipe for a creamy chicken dish done for 3 hours in a slow cooker on low. My husband has issues with corn products and I’d like to use a different starch to thicken the milk base other than corn starch. Which starches would you recommend for this application?
    Reply
    1. Elisabeth Allie
      All purpose flour!
      Reply
  16. Josh
    Hi there is your potato starch free from cross contamination with other starches like corn starch..coz I can't take corn either
    Reply
    1. Ashley Morris
      Hi Josh, please email [email protected] for help with your request. Thank you!
      Reply

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