Have you ever cooked white rice and it turned out yellow? (Frustrating, isn’t it?)
It could just be the lighting in your kitchen. But who are we kidding, really?
The resulting rice is definitely yellow when it should have been heavenly white!
Debating whether to throw out the lights, or the yellow rice out the window?
Don’t do any of those just yet. I think it’s better to figure out the question, “Why is my rice turning yellow?” before anything else.
White Rice Turned Yellow After Cooking
Several factors contribute to why white rice turns yellow:
Storage
Leaving cooked rice at room temperature for more than 2 hours causes bacterial growth. As such, it leads to rice turning yellow and even signs of spoilage.
Let’s not forget the improper use of storage containers, as well. Non-airtight containers promote moisture build-up and can lead to discoloration and mold growth.
Ideally, you should consume your leftover rice within 3-4 days of refrigeration.
Oxidation
Another reason rice turns yellow when left out for an extended period at room temperature is oxidation.
This natural process happens when cooked rice is exposed to air. There are natural compounds found in rice that react with oxygen.
When this happens, your rice can turn yellow. Over time, it can even turn brown.
The moisture present in cooked rice also contributes to oxidation. Moisture facilitates chemical reactions that can change the appearance of your rice.
Overheating
Starch is a primary component of rice. When exposed to excessive heat, starch breaks down.
And discoloration may occur because of moisture loss.
Cooking rice on a stovetop at high heat causes the grains to burst and release starch.
The ideal temperature for boiling your rice is 212°F. White rice also cooks for around 15-20 minutes.
Going beyond these two conditions can cause your rice to dry out and turn yellow.
Rice Variety
What rice variety are you using?
High-starch rice, like short-grain rice varieties, is prone to turning yellow when overcooked.
Some rice varieties are also naturally yellow. Saffron and Basmati rice, for instance, are yellowish because of the added spices and pigments.
Alkaline Water
Cooked white rice taking on a yellowish hue can also be caused by the “hardness” (or alkalinity) of your water.
Using alkaline water causes the starch to break down. This can lead to excessive stickiness and yellowing of your rice.
Flavonoids and the Maillard Reaction
Flavonoids are plant pigments responsible for the color of many flowers, fruits, and vegetables.
They may contribute to the vibrant colors of some foods, but they also play a role in the discoloration of others.
Rice yellowing is associated with the upregulation of these flavonoids.
Their increased concentration and exposure to heat or oxygen trigger chemical changes, which contributes to rice’s yellowing.
The Maillard Reaction, on the other hand, is a complex chemical process. It occurs when protein reacts with carbohydrates under the presence of heat.
This process is actually responsible for the browning of bread and the golden color of fried foods. But while it’s linked to browning, the Maillard reaction can also cause yellowing.
Under high temperatures for extended periods, the reaction happens, thus leading to the yellowing of rice.
Why Does Rice Turn Yellow in Rice Cooker?
Using the rice cooker is usually a foolproof method. Despite this, overheating can still occur.
Leaving your cooked rice in the ‘keep-warm’ mode for more than 12 hours can cause it to dry out and turn yellow.
Uncooked Rice Yellow
Keeping rice grains stored for over a year increases the risk of yellowing, especially under poor storage conditions.
Uncooked white rice can be stored in an airtight container. Make sure to keep it in a cool, dark place for a maximum of one year.
Can You Eat Rice That Has Turned Yellow?
Not all yellow rice is a lost cause. Some discolorations are harmless enough for consumption.
Here’s how you can distinguish an edible yellow hue from spoilage:
Discoloration
Any slight yellowing isn’t exactly a safety concern just yet.
It may only be a coloring issue, an aesthetic concern at most. After all, there are many rice varieties on the market.
If the yellow color is even, it’s more unlikely that it’s caused by spoilage.
Of course, you can always just smell it. Freshly cooked rice, even if it’s yellowish, will have a pleasant smell.
Here are some tricks that you can do to prevent your rice from turning yellow after cooking:
Right Water-to-Rice Ratio
For every rice variety, there’s a water-to-rice ratio to follow. Most white rice varieties cook best with 1 cup of rice and 2 cups of water (1:2).
You can always experiment with different rice varieties. This will help you find the water-to-rice ratio that works best for you.
Reheat Properly
Whenever you reheat rice, make sure the temperature reaches about 165°F. This level of heat can kill potential bacterial infestations.
You can use a stovetop or a microwave. Just make sure you break up the rice and add a splash of water or broth to keep it from drying.
Rinse Thoroughly
Rinsing rice removes any excess starch. Too much starch contributes to the sticky texture and sometimes, the slight yellowing.
Simply place your rice in a strainer and rinse with some cold water until it runs clear.
How Do You Know When Rice Goes Bad?
If you notice a deep yellow that’s almost too orange-tinted and concentrated in spots, it’s a sign of bacterial growth.
Paired with a sour, musty, or ammonia-like odor, and you have yourself spoiled rice.
In addition, fresh rice is fluffy in texture. If yours is slimy, then it’s spoiled.
And of course, watch out for the presence of mold. Whether yellow or not, mold is a definite sign that you should discard your rice.
Any attempts at saving it would just be futile.
What are you going to do? Pick out the moldy patches? Reheat it?
Major no on both.
What is the Yellowing Disease in Rice?
The Rice Yellow Mottle Virus (RYMV) is a disease that infects rice crops. It causes yellowing and is a problem in African rice-growing regions.
Beetles, grasshoppers, cows, rats, and donkeys transmit RYMV.
Common symptoms include yellow-green oblong spots on the base of the younger leaves. And those formed after are mottled and twisted.
Yellowed rice, on the other hand, is a term used to describe rice grains that have been contaminated by Penicillium fungi.
While not all yellow rice poses significant health risks, it is still best to avoid consuming contaminated rice.
Is This the End of Yellow Rice?
So those are the reasons behind the question, “Why is my rice turning yellow?”
The perfect fluffy rice doesn’t seem like a faraway dream anymore.
Understanding the possible causes is vital. Follow it with prevention strategies and your rice will never turn yellow again.
So, what are you planning to do now?
If you’re in doubt, I suggest choosing the side of caution and just dispose of the rice.
Keep the kitchen fun and free of spoiled rice, Foodies!
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