Navy bean soup

Soup inna bread bowlUmami, or, why soy sauce makes everything delicious

Much as I’d love to be the person who can assemble a delicious meal before leaving for work and leave it to simmer in the slow-cooker all day, greeting me at the end of the day with its tantalizing aroma, more often than not I just throw some beans in the pot before running out the door. It’s not a bad strategy–coming home to cooked beans is a step in the right direction. And I recently had an epiphany that makes it even better: soy sauce. More specifically, adding soy sauce to the cooking water makes the beans instantly delicious (well, you know, 6 hours later when they’re cooked). Actually, adding soy sauce to pretty much anything makes it pretty awesome, but today is about beans. And umami, the great taste itself.

NPR’s Robert Krulwich traces the history of humans and their taste buds in his 2007 article “Sweet, Sour, Salty, Bitter… and Umami.” And while the ancient Greek Democritus’ assessment of sweet tastes as round and salty as triangular is not super scientific, the more recent study of specialized receptors on our taste buds is slightly more rigorous. And as it turns out, the four classical tastes of sweet, sour, salty, and bitter are joined by a fifth–umami.

Your tongue is like a coin-sorting machine.

http://www.ritecount.com/shop/images/SM_High_WC3075.jpg

Photo credit: www.dutchforce.com

These machines can use things like the size and weight of the coin to determine if it’s a penny or a quarter and slot it into the right bin. Except instead of coins, we’re dealing with flavor molecules–sugars for sweetness, salts for salty, proteins for umami. When you put something in your mouth, it’s like loading up your coin sorter. The specialized receptors on your taste buds catch their corresponding flavor molecules and send signals to your brain–hey, this is sweet! The combination of all of the signals from all of your taste buds gives you the overall impression of taste, letting you distinguish, say, rice from green beans from ice cream. Your nose also plays a huge role in taste, bringing lots of other types of flavor molecules into play. (Side note: try closing your eyes, plugging your nose, and eating a Starburst. Can you tell what flavor it is? Now unplug your nose. This blew my mind a few months ago.)

In the late 1800s, Japanese chemist Kikunae Ikeda discovered what scientists would later confirm in 2002: we have a fifth receptor for the hard-to-define flavor umami (Japanese for delicious). Chemically, it’s pretty simple: the amino acid glutamic acid is one of the basic building blocks of proteins in humans and all living things. When it breaks down during fermentation or curing, it becomes L-glutamate, and it’s that guy that interacts with our tongues.

Glutamate

Glutamic acid (top) and monosodium glutamate (bottom).

The most commonly used commercial form of L-glutamate is the infamous monosodium glutamate, or MSG (shown above). Despite its bad reputation, it’s really just concentrated umami flavor, and it’s delicious (and no reputable study has corroborated its supposed side effects). So what is umami flavor? It’s meaty and complex and really can only be described as that other taste that isn’t sweet, salty, sour, or bitter. It makes almost everything delicious, and it’s sometimes hard to come by in a vegetarian diet. But with a little care, you too can be blown away by umami: try soy sauce, mushrooms, caramelized onions and garlic, or Parmesan cheese, and you’ll discover that fifth coin that our tongue can taste.

Simmering soupNavy bean soup

To be honest, this is one of those soups that I made by throwing a lot of things into a pot together, so feel free to add whatever you’ve got lying around. I’m a big fan of my immersion blender, so I couldn’t resist just pureeing everything up in the end, but that’s also optional. Finally, I served this in some delicious homemade bread bowls–my next post.

Yield: about 3 liters (a big pot full)

1 lb. dry navy beans

1 T. soy sauce

1 onion

5 cloves garlic

1 T. olive oil

3 red bell peppers

2 large carrots

3 potatoes

5 c. vegetable stock

1 c. frozen corn

2 t. salt

1 t. pepper

1 t. rosemary

Splash hot sauce

Ingredients assembled

Throw the navy beans in a slow-cooker and cover with water to about 2 inches above the beans. Add the soy sauce and cook on low heat at least 6 hours, or about 10 if you’re like me and just leave it all day.

Chop the onion and mince the garlic. Heat the olive oil in a large pot and saute the onions for about 5 minutes, then add the garlic and cook until the onions are soft and slightly browned.

Mmm onions

Chop the bell peppers, potatoes, and carrots, and add them to the pot.

Love the color!

Cook for 3 minutes, then add the stock. Let cook for about 20 minutes. When the vegetables are tender, drain and add the cooked beans and corn. Continue to simmer until everything is hot.

Bobbing carrots

Season to taste and puree if desired.

Blender!

Soup!