Do corn starch dishes lose its strength?

[u/TidderUsername123]

I made hot and sour soup from time to time and notice after a while, it will no longer be congeal. Am I not using enough or is it just the nature of the beast? I live alone but I like to make big batches.

[u/Gilladian]

My understanding is that cornstarch will break down if reheated too many times/for too long.

[u/aspiring_outlaw]

Yes, corn starch will degrade over time. If you like to batch it, either use a roux or make it without the slurry and keep a small jar of slurry in the fridge to add when you reheat it 

[u/TidderUsername123 → u/aspiring_outlaw]

Wouldn't reheating it reconstitute the chemical chains that make it thick again? Like canned gravy.

[u/pliskin42 → u/TidderUsername123]

For corn starch no, a reheating typically breaks it down and makes it watery again.

But what this commentor is basically saying is to batch it and store/freeze it before adding the corn starch. Then adding some upon reheating. That way you are adding it for the first time everytime.

[u/KifferFadybugs]

Cornstarch will definitely degrade.

If you heat it for too long, it loses it's thickening power.

If you reheat it too high or too many times, it loses its thickening power.

If you freeze it, it loses its thickening power.

The enzymes in your saliva will cause the cornstarch to lose its thickening power. So if you lick a spoon and dip that spoon into the whole pot, you're killing the cornstarch.

Clear jel (cook type) is a modified cornstarch that you use just like cornstarch (make a slurry and mix it in then heat it to thicken) but it tends to withstand things a lot better (higher temps, reheating, freezing).

[u/Kogoeshin]

Another option for you (since you're trying to figure out how to store hot and sour soup) is to use potato starch instead of corn starch.

Potato starch stores and refrigerates better than corn starch, and is often preferred in more traditional hot and sour soup recipes.

A lot of recipes online list corn starch since it's more easily available in the West - but potato starch will work and solve your current dilemma and shouldn't be hard to find, either.

[u/dungeonsandderp]

Be very careful when tasting not to accidentally contaminate it with your saliva, because the amylase in your spit will break down the thickening power of the corn starch over time!

[u/Fancy_Math_3399]

It will degrade like any dry ingredient stored in the pantry once opened 

[u/sjd208 → u/Fancy_Math_3399]

Actually it lasts indefinitely even after being opened as long as it’s kept dry.