You will come across at least three or four onion varieties at the supermarket. Although all of them are sweet, the sweetness varies for each type of onion. Certain recipes like salads, relishes, garnishes, and curries taste best when prepared with the sweetest onions. So, what onions are sweet?
Vidalia, Walla walla, and Maui onions are sweeter than others. They also caramelize nicely and impart sweetness to dishes. Red onions, yellow onions, shallots, and white onions are also sweet, but their sweetness is balanced by pungency. Shallots and yellow onions are sweeter when cooked than raw.
Let’s now talk about the sweetness of onions in more detail.
Do All Onions Have Sugar?
Like most vegetables and fruits, onions have natural sugars. However, the amount of sugar varies from one variety to another.
Although all of them will have some sweetness, many onions don’t taste too sweet because they have compounds that compete with this flavor.
Most varieties taste more pungent than sweet because they contain more sulfur.
So a distinct sweetness is more evident in some varieties than others.
It’s easy to eat raw onions with high sugar content. They taste good in salads, relishes, and garnishes.
These sweet varieties will also caramelize well. When you cook them, their complex sugar compounds break down into simpler forms that are sweeter.
This creates delicious sweet flavors and adds a deep brown color to the dish.
Now, let’s take a closer look at the most common varieties of onions and how they compare in terms of sweetness.
Yellow onions are the most popular and commonly used variety of onions. They are abundantly available and inexpensive.
These onions have a rich ivory color beneath their thick brown skin. They have a balanced flavor that’s both pungent and sweet.
Although yellow onions have sugar, they don’t taste good when eaten raw because of their high sulfur content.
However, these onions caramelize beautifully and add more flavor to dishes.
Heat brings out their sweetness. Cooking them also cuts their pungency and allows the rest of their flavors to shine.
Red onions have a beautiful red color on the outside and inside. They contain sugar and are very sweet but not too pungent. Hence, you can eat them raw.
Although red onions caramelize when cooked over low heat, they aren’t the best choice for cooking. They taste better in the raw form.
You can add red onions to salads, garnishes, and salsas for a sweet, tangy flavor. They are crispier than yellow onions and add sharpness to a dish.
The sugar levels of red onions are comparable to that of yellow onions. However, they taste sweeter because they contain fewer sulfur compounds.
White onions have pure white skin and white layers. They have a sharp but sweet flavor.
However, they are milder than yellow and red onions and can be eaten raw.
They don’t have a lingering after-taste. They also taste good when cooked.
These onions are sweet because they have sugar and less sulfur.
The sweetness is prominent and overcomes the pungency. However, white onions aren’t as sweet as sweet onions.
As the name suggests, sweet onions are the sweetest variety of onions. They are larger than yellow onions and easily available.
You can recognize them by their light skin and flattened appearance.
These onions contain more sugar than other varieties. They also have a nice crispy and crunchy texture.
Hence, they taste delicious in salads, garnishes, sandwiches, and burgers.
The extra sugar in sweet onions makes them perfect for caramelizing. If you heat them, they become soft, mushy, and brown.
They add a lot of flavors and make curries, stews, and casseroles taste delicious.
Since sweet onions have a higher concentration of sugar, they spoil faster than other varieties.
You can store them at room temperature if you will use them up quickly.
However, if you wish to keep them for a long time, remove the peel and store them in the fridge.
But remember that storing them in the fridge will affect their texture. The onions can end up becoming soft and mushy.
Commonly available sweet onion varieties include Vidalia, Maui, and Walla walla.
Although shallots are onions, they’re much smaller than other varieties. They have thick brown skin and pink flesh inside.
They have intense flavors and are very pungent. They also have a delicate sweetness which is balanced by a hint of sharpness.
Shallots taste sweeter than yellow and red onions. However, their strong pungency cuts their sweetness.
These onions become sweeter when heated. They caramelize quickly, and the sugar in them transforms their color into a beautiful shade of brown.
Why Are Vidalia Onions Sweet?
Vidalia onions are one of the sweetest onion varieties. They taste almost sugary sweet, and you can eat them like fruit.
Now, here’s something interesting that you may not know about these onions.
According to the U.S Code of Federal regulations, Vidalia onions should be one of certain varieties.
Additionally, they should grow in select counties around the city of Vidalia in Georgia.
It’s because geography has a huge bearing on the taste and flavor of Vidalia onions.
The area where Vidalia onions grow happens to be in the middle of the Atlantic coastal plain, where flowing water dissolves the sulfur and removes it from the surface of the soil.
This produces milder onions that are both sweet and soft.
What Onions Are Sweeter – Red Or Yellow?
Both yellow onions and red onions have appx 9g of sugar and 11g of carbs. So the sugar content of both varieties is comparable.
However, it’s easier to bite into a red onion than a yellow onion because it’s sweeter.
This is because yellow onions are more pungent. Their strong astringent flavor prevents their sweetness from shining through.
Now, cooking yellow onions will cut their pungency and release sweet flavors. These onions caramelize easily and impart delicious sweetness to a dish.
However, the same doesn’t happen when you cook a red onion. Although they caramelize, the flavors are not as rich as yellow onions.
Which Onions Are Sweeter When Cooked?
Many recipes like casseroles and tray bakes call for the caramelization of onions. This process changes the texture and taste of onion and creates a new flavor.
Now, caramelization is the process of heating ingredients to release their sugar content and make them acquire a rich brown color.
When you heat onions, a chemical change occurs. Heat breaks down the complex sugars in the onion.
These complex sugars transform into simpler forms like glucose and fructose, which taste sweeter than complex sugars.
Your taste buds can pick their distinct sweetness. Hence, you will find it easier to recognize their flavors than the complex sugars in a raw onion.
In addition to this change, the color of the onion also changes. It first becomes translucent and then turns into a rich brown color. This process is called pyrolysis.
While all onions caramelize, those with higher sugar content do better than the others. The texture of the onion also plays an important role in aiding caramelization.
Heat enhances the sweetness of yellow onions and sweet onions. Hence, they’re the best onion varieties for caramelization.
These onions turn soft and add more texture to a dish when cooked. They also become very sweet upon exposure to heat.
To help these onions develop even more of a caramelized flavor, you can add a pinch of sugar to them.
Other varieties like red onions and white onions also caramelize. However, red onions taste better when they are raw than cooked.