All you wanted to know (and probably more!) about Cornstarch

The other night I was coming back from a birthday party with Wally and a couple of friends when, I don't even remember how, the conversation ended up on the meaning and origin of the word Tiramisu. Wally was mentioning that it did not really sound like an Italian word to him (that's how much of Italian he know after more than a year with me!) and so I improvised an explanation of the name of the famous Italian dessert, or at least the little I could remember from something I read somewhere, some time ago.

OK, "what does tiramisu has to do with cornstarch?" you might be thinking. Nothing! But from this uninteresting episode I got the idea of some random posts about an ingredient, or a dish, or anything else related to cooking (in particular to baking). I am always curious about the origin of a word or a dish or about alternative uses of many ingredients, even outside the kitchen. I think that a series about this would stimulate me to do some research and find the What, Where, When, Why, Who (and maybe also the How) of many more things aside from Tiramisu (and I'm not going into the derivation of the word Tiramisu in this post...I'm sorry!)

So, here I am with this first post and my first guest: the Cornstarch. Why on earth did I choose the cornstarch to start this series? Well, there are one (or two) very simple reasons. I realized today that I run out of cornstarch! I am usually very lazy and do not go to the store to buy only one ingredient but I figured that for the sake of this post I would have fought laziness! So, there you go: I just got back from the store where I got my new box of cornstarch. Honestly, there is another reasons for choosing cornstarch: it can be use for soooo many purposes that I thought it could have been fun to do some more research about it. Turned out: I was right!

THE ESSENTIALS:

What: Corn starch, cornstarch, or cornflour in the United Kingdom, Ireland, New Zealand and Australia; Amido di mais or Maizena in Italian and Spanish. It is the starch of the corn (maize) grain obtained from the corn kernel.

Where: Cornstarch can be found in any regular store. It appears as a thin white powder but it can also be mixed with sugar to obtain confectioner's sugar. It can be stored safely for several months in an airtight container in a dry, cold place.

When: it can be found all year round

Why: here comes the reason why I am so interested in cornstarch. 
First of all, it is a thickening agent, which is why we add it to soups, sauces, stews, and gravies. Here are a few tips for using cornstarch as a thickening agent:

• Cornstarch is a “super-thickener” compared to flour. The starchy granules attract liquids and expand, but only for a short time and not at high temperatures. Use only half as much when substituting for flour. The exception is acidic foods; these will decrease the power of cornstarch.
• Always make a paste of cornstarch and cold water (called a slurry) before adding to heated foods to prevent lumping. Do not overcook as it will begin to break down and thin out. Stir continuously but gently. Vigorous whisking will also cause loss of texture.
• When cornstarch paste is added, cook over medium heat and bring to a boil for about one minute. Remove and serve.

Second, cornstarch is also a binder. That's why we use it in custards, creams, puddings, hot chocolate, etc. A couple of tips also on cornstarch as binder:

• Cornstarch can cloud a clear sauce but creates a nice sheen on pie crusts.
• Blend it with flour for a richer texture in cakes and pies.

Who (and also How): well, naturally every grown up who cooks and bakes have a chance of using cornstarch. However, also kids can have a chance of using cornstarch and having a lot of fun. Actually, they usually LOOOVE it. How come? Well, some people don't know (I didn't either before starting working with children) that cornstarch, when mixed to cold water or milk, becomes a Non-Newtonian fluid. What the heck is a Non-Newtonian fluid? In few words, it's a fluid that changes consistency when pressure is applied to it. If you pour water in a bucket and then add some cornstarch the kid sees an opaque liquid. However, when he puts his hands into the mixture he realizes that it is not liquid. He can touch it...it's solid and slimy when gently touched. At the same time, it will resist sudden pressure and if the child tries to take his hands out of the mixture while retaining some of this weird mixture in his hands he will realized that it is not possible. You should try, even at home...It is a super fun material to play with, not only for kids and if you get well organized it's not that messy (less messy than paint if you think about it!)

So much for what I meant this post to be about...However, while looking around for information on cornstarch online I have found out that it can be used for many many many purposes outside the kitchen. I will mention only a few here and send you to the original sources for an extensive list, such as this.

Here are a few examples of unusual uses:

• Clown makeup: mix two parts of cornstarch with one part of white vegetable shortening to make a non-toxic grease paint. If you want different colored clown makeup just add a few drops of food coloring until you get the desired shade.
• (non-toxic and edible) finger paint: mix a quarter cup of cornstarch with two cups of water and boil it on the stove until it is the consistency of paint. Separate the goo into a few dishes and add food coloring to each one. 
• Some parents use it as an alternative to baby powders, which some sources claim to cause respiratory problems in babies because the very thin powder is easily inhaled.
• It is used to improve the texture of paper, as ingredient in some medicines, in the production of soap and sometimes of beer, because it is cheaper than barley
• In the gluten free cuisine, it's used mixed with other flours as a substitute of wheat flour
• Relieve sunburn pain: add enough water to corn starch to make a paste, and apply directly to the burn.
• Clean a carpet: sprinkle corn starch on the carpet, wait thirty minutes, then vacuum clean.
• Clean blood stains: immediately cover the spot with a paste of corn starch and cold water. Rub gently, place the object in the sun until dry to draw the blood into the corn starch, then brush off. Repeat if necessary....this seems to take a long time to work...that's probably why they don't use this trick in mystery movies :))) 
• Clean silver: make a paste with corn starch and water. Apply with a damp cloth, let dry, then rub off with cheesecloth. 
• Remove grease or oil stains from smooth fabric: apply corn starch to the spot, wait twelve hours, brush off, then launder as usual.

People often wonder what the difference is between cornstarch and flour. Both are cereal starches, but cornstarch is pure starch while flour contains gluten. The gluten reduces the thickening power of flour. Therefore, if one tablespoon of cornstarch thickens one cup (250 ml) of liquid to a medium consistency, it takes two tablespoons of flour—twice as much—to thicken the same amount of liquid.

 Substitutions:  

 2 tbps all-purpose flour = 1 tbsp cornstarch

 2 tbps granular tapioca = 1 tbsp cornstarch
 1 tbps arrowroot flour = 1 tbsp cornstarch

Sources:

http://www.stevespanglerscience.com/experiment/00000088 has step by step pictures of how to make quicksand

http://www.essortment.com/home/unusualusescor_sxri.htm
http://www.exploratorium.edu/science_explorer/ooze.html

Cornstarch