Today’s lesson in French fries will center around the greening of potatoes. There is no doubt in my mind that you have eaten French fries that taste pretty good at first and then bam, your taste buds jump from a pungent flavor similar to raw grass. What you are tasting is called “greening” and it comes from improper storage of potatoes. Particularly those that have been exposed to temperature extremes and light such as fluorescent lights. The raw grass taste comes from chlorophyll that develops in the skin.
I bring up greening because the fries I tried at Square Burger were almost inedible because of the aftertaste of chlorophyll. I have all the respect in the world for the grass-fed burgers they serve, but the fries I was served last Saturday had no business tasting more like grass than the burgers. Any kitchen worker who knows their way around hand-cutting a potato should be able to recognize a potato that has not been stored properly.
I asked my friend Dr. Potato , the vice president of foodservice for the Idaho Potato Commission, to shed the correct amount of light on the subject:
Along with this [greening] change, an increased quantity of solanine is also formed. Solanine, a glycoalkaloid present in all potatoes, is actually part of the flavoring complex that gives the potato its taste.
More of this naturally occurring substance is found in some varieties than in others. In the Russet Burbank, the level is very low. But in all varieties, green potato skin is an indication that excessive solanin is present. The brighter the color is, the higher the level or solanine and the more bitter the taste.
Solanine is generally concentrated close to the potato’s surface and is easily removed when peeled. Only if the potato has had prolonged exposure to light will the bitter taste and color penetrate into the tuber. The green portions can easily be discarded in preparation.
There is little concern about solanine being harmful. At levels that could cause adverse reaction, the solanine level would have to be so high that the potato would be inedible. Furthermore, solanine, if accidentally eaten, does not accumulate in the body. Animal research shows that it is poorly absorbed and rapidly excreted.
Dr. Potato tells all of his clients to store potatoes in Poly Film, burlap, and cardboard containers designed to filter or block out light. Until Square Burger shows a higher respect for potatoes, I will stick to eating their miraculously decadent grilled cheese sandwich served with an insanely delectable fried pickle spear. If they screw up the pickle, they’re off my list forever.