A brief history of lettuce, America's first fresh vegetable

lettuce
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Before inventors figured out how to ship iceberg lettuce across the continent, people subsisted on root vegetables for most of the year.

Have you ever stopped to think about lettuce, that humble workhorse of a vegetable that shows up on dinner tables at least several times per week? That such a fragile, perishable, and seasonal food has become an integral part of the American diet is really quite curious, and its history is traced in a fascinating episode called "Green Gold" on CBC's The Fridge Light podcast with Chris Nuttall-Smith.

Lettuce was the first fresh produce that Americans were able to buy any day or week of the year. Prior to this, they relied on root vegetables like cabbage, potatoes, and carrots. Lettuce exploded onto the culinary scene when growers in California's Salinas Valley figured out how to send train cars filled with iceberg lettuce across the continent to diners in New York City, Boston, and Chicago. Iceberg has the unique ability to stay crisp and fresh if its ambient temperature is maintained at 32 degrees Fahrenheit (0 C). It has a long shelf life of 21-26 days, fourteen of which were needed to reach Chicago at the time. The Salinas Valley also had access to electricity to power ice-making plants, where 30,000 pounds of ice were produced daily to fill the rail cars, below and above the lettuces.

By the 1950s iceberg lettuce was the most commonly consumed lettuce in the U.S., with average per capita consumption around 20 pounds. Refrigeration technology developed to the point that iceberg lettuce was even shipped to American soldiers in Vietnam.

But then, the iceberg growers and packers, who were always looking to improve their business model, realized that not all heads of lettuce got fully eaten because they were only ever sold in a full-head form. That led to the next revolutionary invention -- that of bagged salad greens.

What I never realized was how complex those plastic bags of greens are. Jim Lug, who worked to design the first bags, told Nuttall-Smith that there are numerous layers within the plastic that you cannot see. One layer is to seal the bag, another allows for oxygen transmission, another provides a layer for printing graphics, and one is for carbon dioxide management -- all this within the see-through packaging of salad mix. (This doesn't make it any better from an environmental point of view! I still hate those bags for their non-recyclability.)

Their invention, however, meant that farmers could now ship more fragile lettuces, like Romaine, arugula, endive, Boston bibb, butterhead, and radicchio, further afield. As a result, mixed salad greens, or mesclun mixes, became a normal part of the American diet. (Not necessarily a good thing, as Melissa wrote in her alarming post, 7 reasons to ditch packaged greens.)

This process was aided by renowned restaurateurs such as Alice Waters at Chez Panisse, who sought out organic salad greens. One researcher, Julie Guthman, said on the episode that salad greens were "the first commodity to make organics attractive to mainstream shoppers." They're what turned the tide of public opinion from viewing organics as "hippy food" and turned them into desirable "yuppy chow."

We've now reached a point where lettuce is so normal that's is almost boring. It's the vegetable nobody really thinks about, that everyone takes for granted because it's so cheap and available; and yet, as Nuttall-Smith points out, most Americans only know the tip of the iceberg, so to speak, when it comes to lettuces. There are countless flavourful and unusual varieties that are not even available in supermarkets. Getting to know these would take our appreciation of lettuce to a new level.

That's just one more reason why I'm so happy to be a member of a CSA share that fills my fridge to bursting with salad greens every week. We get different varieties in such quantities that, at this time of year, my family has to eat salad with every meal or else we won't finish it all before the next weekly batch arrives. I'm still not an advocate of bagged salad greens for many reasons, not least of all because I try to eat as seasonally, locally, and waste-free as possible -- and yes, that does mean going without green salad for months on end in the winter -- but that does not make the history of this ubiquitous veggie any less intriguing. "Green Gold" is well worth a listen if you enjoy your salads.

A brief history of lettuce, America's first fresh vegetable
Before inventors figured out how to ship iceberg lettuce across the continent, people subsisted on root vegetables for most of the year.

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