Ask The Food Lab: Should I Brine My Corn?
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"Should I Brine My Corn?"
I've seen a number of recipes in magazines, newspaper, and online recently that say that soaking shucked corn in salt and sugar water before grilling will make it plumper and juicier. Is this true?
—Sent by Captain Foodtastic
First let's define exactly what we're talking about here. Soaking corn in water while still in the husk is old news. It's a good way to help your corn steam if you plan on throwing it directly on the grill (or onto a bed of hot coal), especially if your corn is slightly past its prime and its husk has started to dry.
What we're talking about here, however, is something different. The suggestion is to brine shucked ears of corn in a salt or salt and sugar brine just like you would a pork chop or chicken breast to keep it moist while cooking. The technique first appeared around 2009, and has been making its rounds of the internet ever since.
At first glance, the process makes sense. If soaking meat in brine makes it plumper and juicier after cooking, why wouldn't the same work for corn?
Most sources seem to recommend a half cup each of kosher salt and sugar for a gallon of liquid, brining for anywhere from 30 minutes to 8 hours. For my first test, I tried following these instructions exactly, starting with one ear of corn at four hours, and comparing it to corn that was completely un-treated.
Before cooking it, I noticed something strange with the brined corn:
Its kernels had begun to deflate, just like little balloons. Cooking up the two ears side-by-side showed that the brined corn was significantly less juicy, with the kernels a little mealier and denser.
Was it just a fluke? How could so many websites and magazines claim to have found positive results from brining when my quick test showed the opposite results?
I decided to take a more rigorous approach to this and work systematically. Over the next couple of weeks, I tried brining ears of corn in brines of varying strengths (starting with plain water and going up to a fully saturated solution), and various lengths of time from 30 minutes to one day. I repeated each test three times using corn bought from different sources each time to ensure that all my bases were covered.
Time after time I came up with the exact same results: The longer you brine and the stronger you brine, the dryer and tougher your corn becomes.
And the difference is not just minor. It's dramatic. Take a look at the corn below, each brined for three hours in brines of varying strength.
The ear on the left, a control which was soaked in just plain water, showed no differences from completely un-soaked corn, while as the brine got progressively stronger, the corn dried our more and more. Why does this happen?
Let's first do a quick recap of the basic mechanics of brining meat so that we can understand how the process applies to corn.
When you submerge a piece of meat—say, a turkey breast—in a bath of sufficiently salted water, at first, some liquid will get drawn out of that meat through the process of osmosis, the tendency for water to travel across a semi-permeable membrane (in this case the turkey's cell walls) from an area of low solute concentrate (inside turkey cells) to an area of high solute concentrate (the saltwater bath).
Subsequently, the salty brine will begin to dissolve proteins in the turkeys muscles (mostly myosin), which allows that structure to loosen up and reabsorb the liquid, taking some of the salt with it. Through this process, the salty liquid will slowly work its way into the turkey.
Moreover, the turkey retains these properties even after cooking, resulting in a plumper, juicier breast.
The graph above represents the weight gain and loss of turkey soaked in water, brine, and left au natural*
*Please ignore the small hump in the "plain" line, it is an artifact of a poor curve algorithm choice
With an ear of corn, we still get the first half of that process—the loss of water due to osmosis—but we don't get a subsequent re-absorption due to loosening of muscle fibers because, well, corn doesn't have muscles.
So are there any actual positive results from brining your corn? Not really. The best you could argue is that the corn becomes more deeply seasoned, as some of the salty-sweet water works its way in between the kernels. But this is nothing that can't be compensated for by seasoning the corn itself right after it comes off the grill (or better yet, seasoning the butter that you're going to melt all over it).
The real question that persists is: if we can prove over and over that this method produces inferior corn, then how the heck did it get printed in the first place, and why does it continue to be perpetuated?
What we're really seeing here, folks, is a food myth in the making and it works the same way all food myths work. The myth is born and passed on from one in a position of authority to its disciples. Then, through a nefarious pattern of deviation in human judgment known as belief bias, people allow their beliefs of reality to cloud their perception of actual reality.
My strong suspicion is that the original source of the corn-brining technique* did not sufficiently test their theory, or were perhaps inclined to ignore some testing results in favor of producing a story with a good hook, and that in all subsequent mentions of the results, nobody actually tasted the brined versus un-brined corn in a blind, scientifically valid taste test.
*Who I won't name, but should be easy to figure out with a bit of reading and googling
Let's nip this food myth-in-the-making in the bud and save ourselves some trouble in the process, shall we?
For the best direct, out-of-the-husk grilled corn, skip the brine: use fresh corn, throw it over hot coals, and turn it until its done.
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About the author: J. Kenji Lopez-Alt is the Chief Creative Officer of Serious Eats where he likes to explore the science of home cooking in his weekly column The Food Lab. You can follow him at @thefoodlab on Twitter, or at The Food Lab on Facebook.