The gist of why it's precarious:

But the Honeycrisp is also a “finicky" apple, Merwin said. Honeycrisp growers estimate that it costs two to three times as much to produce as do top-sellers like Fuji and Gala. Originally bred in Minnesota, the Honeycrisp tree prefers colder climates, where the season only lasts between September and December. The fruit itself is delicate and, as a result, doesn't store well long-term. “If you drop an apple two inches, it's bruised," Merwin said.

This partly explains why, while your standard “low-grade" apples such as Red Delicious, Gala or Fuji sell wholesale for roughly $100 a bin (800 to 1,000 pounds of apples), Honeycrisps go for about four times that. Top that with a markup of two or three times the wholesale cost—more than $3 a pound, compared to about $1.50 for Red Delicious—and they're still one of the most profitable items in the supermarket.

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It's not yet clear how long the Honeycrisp can sit in storage before it starts to lose flavor and texture. Demand is still so great that the apples sell before they go bad. In this sense, an apple breed's hype is a self-fulfilling prophecy: If you can get your hands on a Honeycrisp, it will taste fresh and good. Meanwhile, the Galas one bin over might have been in storage for months—and taste like it.

The Gala was 2015's most popular apple, but it now takes an extra year to sell the annual crop. According to Merwin, the fruit should not be in storage for more than three or four months. “It's an aromatic apple," he said. “It will look like a really good Gala, but if it's eight or 10 months, it won't have the flavor."

Recently, some experts have started to warn against planting new Honeycrisp trees, which will take about eight years to reach full production while sturdier varieties enter the marketplace. They predict the Honeycrisp will inevitably oversaturate the market and prices will come crashing down—just like they did for the Red Delicious.

The success of the Honeycrisp ushered in a new wave of designer apple breeds like Ambrosia, Jazz, Cosmic Crisp, Ruby Frost and Snap Dragon. 

But it would be premature to say any one of these catchy-named upstarts will permanently unseat the Honeycrisp. “Apple varieties and fruit varieties are a fashion," said Courtier. “Varieties come and varieties go."

It is safe to say, however, that the next big thing in apples will share the Honeycrisp's signature crunch. “The crisp gene of Honeycrisp is the one that changed the game. That's when people decided they wanted their apples to be crunchy," said Jacobson. “In 15 to 20 years, just about every apple you buy at the grocery store will be crunchy like a Honeycrisp."

Just as important, the Honeycrisp brought back consumers who had been turned off by stale apples, reinvigorating the industry as a whole. The newfound interest in high-quality produce paved the way for small, local producers like Merwin, whose apples will never sit in storage. “Our country has gone through an incredible awakening about food," he said. “Half the growers I know wouldn't be in business if it weren't for that."