Seven years have passed since the fast-food giant last added a new U.S. potato variety to three previously approved for its golden fries, something that both irks and motivates potato researchers who hope their progeny will be next.
Because McDonald's buys more than 3 billion pounds of potatoes annually across the globe, it has the power to dictate whether a variety sprouts or winds up in the less-lucrative supermarket freezer's crinklecut bin or dehydrated taters.
To be sure, McDonald's has increased its use of other potato varieties in the last decades.
Early-maturing, Canadian-bred Shepody potatoes go into many of its fries sold in August, September and October. But those potatoes don't store well, so by November, Ranger Russet fries hit the fast-food joints. And better-storing Umatilla Russets -- the last U.S. potato variety approved by McDonald's back in 2002 -- fill the bellies of consumers from late December until the end of February.
From then on, Russet Burbanks, with robust storage qualities, consistent texture and taste, remain Mickey D's mainstay, though this variety brought West by Massachusetts botanist Luther Burbank in 1875 is costly to produce.
McDonald's is now scrutinizing the Bannock Russet, a 10-year-old potato variety bred originally in Idaho that isn't as susceptible to most diseases as Russet Burbanks.
"If we can find a variety that does that, with less inputs, water or whatever, that's something we're looking for," Smith said. "To date, there are not a lot of varieties that perform consistently enough."