EDITOR’S NOTE: This is the sixth and last Apple Culture column, which we’ve been running in conjunction with apple season in Maine (though crazily, just last week we saw peaches in the farmers market, alongside the apples!).

To me, the middle of October is peak apple season. This is when russets ripen – the apples with the most complex, interesting flavors of all. I like these varieties so much that I adopted the term “russet” as part of my digital nom de plume, The Righteous Russet. My editors worried Maine readers might see my email address and Instagram account name and confuse me with a potato expert. But I was willing to risk it. There is, in fact, no “Righteous Russet” apple varietal, but the name stuck after my wife and I mistakenly thought we saw one listed at an orchard where we were picking apples last year.

As this is my last column of the season, I wanted to end by going back to the beginning and sharing my love for the russeted varieties that most inspire my obsession with the heirloom and unconventional apples that grow in Maine.

The idea that October is peak apple season may surprise people who are accustomed to measuring the season’s length with the ebb in availability of locally grown commercial apples like McIntosh and Cortland; these fruits fall off in quality as the season progresses and turns colder. But orchard owners I talked to when I put together a guide to orchards that specialize in unconventional apples for the Press Herald, bemoaned the fact that many Mainers pick Macs and Cortlands in September, then scratch apple-picking off their fall To Do list. They’ve no idea they are missing out on the many excellent varieties, like russets, that need additional time on the tree to develop their exceptional flavors.

The varieties that populate orchards at the beginning of the season are blander because early-season apples need to bulk up quickly, which means they contain far more air and water than later-season apples. They are often mushy and underwhelming – especially when eaten fresh. Russets and other late-season apples, by contrast, are typically crisp and crunchy. They contain high levels of acidity and sugar that play off each other in fascinating ways. The flavors run the gamut: from well balanced or cleanly sweet to floral, astringent or punchy tart, complicated flavors that no early season apple can replicate. Some people liken the taste of russets to pears. It’s the extra tree time to ripen that makes the difference.

“I don’t know if russeting a naturally occurring condition that slightly hardens and browns the skin affects the taste of apples, but all the russets I can think of pack a flavor punch,” says Cammy Watts of Super Chilly Farm in Palermo. “We even have one russet from Albion that tastes like Lemonhead candy.”

Watts and apple expert John Bunker are partners in the Out on a Limb CSA, which offers subscribers a huge diversity of heirloom and unconventional apples each fall. Russets are among subscriber favorites, Watts said.

To no small extent, the first half of apple season is making due with what is available. Then October happens, and the world of apples explodes with possibilities. If September is about using apples creatively, October is about simply picking apples off the tree, taking a bite, and marveling at their flavors.

But please don’t be put off by their looks. Russets are, it must be said, funny-looking apples with brownish skin.

“Not long ago I was some describing some of the odd shapes and colors you see in apple varieties to some kids and when I told them that some apples were brown, they looked at me a bit shocked and asked, ‘like rotten?’ ” said Laura Sieger, a fellow russet aficionado and Maine Heritage Orchard employee. “Some people definitely are intrigued, though, and once you get past that the apple is very different looking, I think it’s easy to appreciate their best qualities.”

What exactly causes the skin to brown – it can range from a small patch to a lattice pattern to an all-over brown – is unclear. One theory is that the russeting protects an apple from rupturing when it grows faster than its skin can otherwise handle. Another is that russetting occurs when an apple accommodates itself to colder climates that produce later frosts.

Although russeting can appear on many varieties that no one would categorize as russets, it is the intensity and prominence of this skin condition that led people to apply the term to particular varieties. Two of the most iconic russets are the Knobbed Russet and the Egremont Russet. The Knobbed Russet really is hideous, with a heavy splattering of russeting. I can imagine a witch in a fairy tale offering this apple to an innocent young girl. David Buchanan of Portersfield Cider in Pownal likens them to “mummified shrunken heads.”

The Egremont Russet, which happens to be my very favorite apple, has a clean, golden skin that gives it a regal quality; it would not look out of place in a still life painting. Despite their disparate appearances, both apples are wonderful dessert varieties – a term used to mean they are good for eating out of hand – with odd and complex flavors.

“Behind the rough texture of russets lie some of the best flavors – they’re incomparably delicious,” Buchanan says.

If you’ve already picked apples this year and scratched the activity off of your fall To Do list, I beg you to reconsider. Return for the russets!

And enjoy the rest of apple season and all the amazing fruit that is yet to come.

Sean Turley is a lifelong fruit enthusiast and an amateur apple picker and sleuth. Every fall, Turley dedicates himself to locating and devouring as many of Maine’s heritage and wild apple varietals as possible. Sean posts his finds on Instagram @therighteousrusset and can be contacted at: therighteousrusset@gmail.com.