The humble onion is often overlooked in terms of importance, but any cook will tell you that its use is varied and interesting in terms of the places it can sneak in and fill a niche. Whether raw, cooked, steamed, boiled, dried and powdered, or fresh and crisp, the onion is a flavour powerhouse. It gives many dishes a mild sweetness to cut through the salty and sour flavours of other ingredients. It caramelises in fat, to give the final dish a deep, dark brown, earthy colour. It's like your Jack of All Trades of the culinary world. I had a dear friend who was wondering about the different kinds of onions, and this entry goes out to her (she knows who she is) for inspiring an entry so early in the morning!
In terms of heat, Spanish (aka yellow) onions have the most kick, in my opinion. They're really good with an even amount of sugars that'll caramelise rather well. They also work extremely well in a sweat, and in raw or other forms. They're your all purpose onion.
White onions are sweeter than Spanish onions. They also have a bit more sugar in them, and tend to burn more easily in a sautee. You don't really want them to caramelise overmuch, but rather, you want to sweat them (turn on the heat, hear the onions sizzle, turn down the heat to as low as it'll go, and let them cook, covered, for like twenty minutes or so, till they're clear). They have subtle undertones that come out very well in a sweat. White onions are also used in Indian medicine (ayurveda), for reduction of phlegm, and to relieve gas, and to increase vitality. They're eaten raw, or cooked.
Red onions are sweeter, but have a sharper, more biting flavour when eaten raw. Try not to cook with red onions, because you'll be missing out on its most powerful weapon: its beautiful colour! Serve reds raw, over soups, salads, etc., with a splash of lemon and a touch of salt.
Vidalia onions are mild, fairly sweet, and ever so hard to find, unless they're in season. They're only grown in a town called Vidalia, in Georgia. Hawaiian sweet onions are sweeter still, but have that same mild, clean flavour working with them. Because they're so expensive, you want to make these onions in ways that will showcase them, and where they're the focus of a dish. Try them in onion rings, or even raw in a salsa or salad. They're quite tasty.
Scallions, or green onions, or long onions, or spring onions (all the same onion!) are the ones with the white part and the green part. The green part has an earthy, "green" flavour, while the white part has more of an oniony bite to it. You want to use as much as you can, to get the combination of flavours that will come out onto the food.
Shallots are much much smaller than regular onions, and looks almost like large cloves of garlic, with a pale reddish/purplish flesh. Use shallots in applications where you will be simmering, rather than sauteeing, so that you don't burn them. You only need a small amount to flavour a lot of food. Shallots are the onions found in a buerre blanc.
Leeks are extremely mild, and are excellent when sweated, to flavour complex, and delicately flavoured soups. The most famous use of leeks is in a vichyssoise, which is a leek and potato soup that's served chilled and pureed. Its flavour is light and airy, and a regular onion would overpower the soup. Also, because the leeks don't have too much sugar, they don't caramelise easily, which keeps the soup very white.
Chives are an herb that's related to onions and garlic (and leeks, oh my!), and that have a flavour that's kind of like a cross between garlic and onion. Use chives raw, as a last minute garnish, for a little bit of an extra kick in the food. It's excellent!
I hope that's inspired you to get out there and experiment with your onions!
In terms of heat, Spanish (aka yellow) onions have the most kick, in my opinion. They're really good with an even amount of sugars that'll caramelise rather well. They also work extremely well in a sweat, and in raw or other forms. They're your all purpose onion.
White onions are sweeter than Spanish onions. They also have a bit more sugar in them, and tend to burn more easily in a sautee. You don't really want them to caramelise overmuch, but rather, you want to sweat them (turn on the heat, hear the onions sizzle, turn down the heat to as low as it'll go, and let them cook, covered, for like twenty minutes or so, till they're clear). They have subtle undertones that come out very well in a sweat. White onions are also used in Indian medicine (ayurveda), for reduction of phlegm, and to relieve gas, and to increase vitality. They're eaten raw, or cooked.
Red onions are sweeter, but have a sharper, more biting flavour when eaten raw. Try not to cook with red onions, because you'll be missing out on its most powerful weapon: its beautiful colour! Serve reds raw, over soups, salads, etc., with a splash of lemon and a touch of salt.
Vidalia onions are mild, fairly sweet, and ever so hard to find, unless they're in season. They're only grown in a town called Vidalia, in Georgia. Hawaiian sweet onions are sweeter still, but have that same mild, clean flavour working with them. Because they're so expensive, you want to make these onions in ways that will showcase them, and where they're the focus of a dish. Try them in onion rings, or even raw in a salsa or salad. They're quite tasty.
Scallions, or green onions, or long onions, or spring onions (all the same onion!) are the ones with the white part and the green part. The green part has an earthy, "green" flavour, while the white part has more of an oniony bite to it. You want to use as much as you can, to get the combination of flavours that will come out onto the food.
Shallots are much much smaller than regular onions, and looks almost like large cloves of garlic, with a pale reddish/purplish flesh. Use shallots in applications where you will be simmering, rather than sauteeing, so that you don't burn them. You only need a small amount to flavour a lot of food. Shallots are the onions found in a buerre blanc.
Leeks are extremely mild, and are excellent when sweated, to flavour complex, and delicately flavoured soups. The most famous use of leeks is in a vichyssoise, which is a leek and potato soup that's served chilled and pureed. Its flavour is light and airy, and a regular onion would overpower the soup. Also, because the leeks don't have too much sugar, they don't caramelise easily, which keeps the soup very white.
Chives are an herb that's related to onions and garlic (and leeks, oh my!), and that have a flavour that's kind of like a cross between garlic and onion. Use chives raw, as a last minute garnish, for a little bit of an extra kick in the food. It's excellent!
I hope that's inspired you to get out there and experiment with your onions!