Essay: Old World Lessons on Spontaneous Fermentation and ‘Wild’ Cider

Left: Apple tree at Keepsake’s orchard. Right: Tom Oliver’s Vintage Fine Cider // Photos by Brian Kaufenberg

Nate Watters is the co-founder and cidermaker at Keepsake Cidery, Minnesota’s only 100 percent spontaneously fermented cidery. All opinions expressed are his own. 

Life is full of moments that change us. Sometimes they are little nudges, gently changing our course—maybe a lyric in a song heard at First Avenue. Sometimes they are hard shoves, changing our course immediately—an honest conversation with a trusted friend about a dead-end job, perhaps.

One of my moments was in the afterglow of a glass of Tom Oliver’s Medium Cider. In the middle of ordering trees and writing business plans, we were sampling ciders from around the world. This particular bottle had probably been recommended by PJ Zavada when he was at South Lyndale Liquors. Another moment.

This was the best cider, and maybe the best drink, I had ever had. It ranked up with my first glass of Duchess or Oban. I had to know more. I wrote a note to Tom and we struck up a conversation which turned into a mentorship and friendship. He is one of my heroes, and I will always be grateful that he took the time to respond back to an inquisitive guy 4,000 miles away in Minnesota.

Tom Oliver is one of the most revered and respected cidermakers in the world. His ciders have depth and flavors found only in his ciders. In his first notes to me, he passed on gems of wisdom regarding temperatures, timing, and the optimal age of the trees from which apples are picked—“50 years-plus.” His most influential piece of advice took almost a year to sink in: no added yeast. He never pitched a milligram of commercial yeast. He never even considered such a thing when he started making cider again on his Herefordshire farm.

As a farmer-cidermaker dedicated to local flavor, dedicated to the place and the seasons of Minnesota, I was intrigued by the use of spontaneous fermentation. I was also terrified—no one else was doing it anywhere even close to us. In 2014, my buddy, Jim Bovino, and I decided to go for it and made the first wild product in the region. We loved it. We creatively called it WILD.

Fast-forward to 2018 and Keepsake Cidery transitioned to a 100 percent spontaneous fermentation cidery, winery, and meadery. No yeast pitched, not one milligram.

“As a farmer-cidermaker dedicated to local flavor, dedicated to the place and the seasons of Minnesota, I was intrigued by the use of spontaneous fermentation. I was also terrified.”

– Nate Watters, Keepsake Cidery

And much to the joy of this cidermaker’s heart, more and more wild and mixed culture products are being made in our great state. We especially love Jace Marti’s work at the Starkeller, Milk & Honey’s 2017 Estate, Mat Waddell’s creations, and Austin Jevne’s genius at Forager Brewing.

As more and more brewers, cidermakers, winemakers, and mazers dig into wild yeast, it begs the question: What is wild yeast? Can you buy it, collect it, propagate it? Or is it spontaneous? Is it all of the above? What is it about wild yeast that attracts me enough to change my direction? I felt like a little particle of light racing through space, being pulled by a black hole.

It was time to go to the Old Country.

My wife Tracy, the kids, and I headed across the pond in late February of 2019 to visit Oliver’s Perry and Cider, Ross on Wye, Greggs Pitt, Heck’s, Pilton Cider, and more in the venerable regions of Wales, Somerset, and Hereford.

Here in the U.S., Keepsake and other 100% spontaneous fermenters are an anomaly. In the U.K.,  among orchard-based cideries, we were the norm. When I asked Welsh and English cidermakers if they pitched yeast, I was usually met with a raised eyebrow and an incredulous grunt. It seemed that almost every small, farm cidery in the U.K. uses no commercially bought yeast.

The ciders we tasted were at times transcendent and at times disastrous. One would shine with flavors of bruised fruit, leather, smoke, and wood, but another cider on the same shelf would taste of a mix of fingernail polish and rotten floorboards. It was a tightrope, a risky affair, where the cidermaker trades control for something richer, higher, and perhaps more rewarding than mass-market appeal. True love. A moment.

My English and Welsh friends seemed to share the same affinity as I for spontaneous fermentation. In a growing craft beverage industry, an industry built on innovation and experimentation, a debate grows as to what wild really means. Just because we do not pitch yeast, it doesn’t mean our yeasts are pure wild or that we are better or worse than a producer who pitches yeast. This is not a moral question. I think it is more of a reflection of the personality and vision of the producer.

When it comes to spontaneous fermentation, everybody is invited, all the yeast and bacteria on the fruit, the press, the clothes, the lines, the tanks, and the air. If there are residual commercial yeast strains on your equipment, they will evolve, reproduce, and populate your facility. Are they now wild? I am not sure there is a clear definition of wild.  I still hesitate to clearly define our cider and process as wild, but in the end, it is a question of our very identity as a cidery—and words matter. They matter to the producer and they matter to the consumer.

For me, wild means a relationship with our house, ambient, wild, native, you-name-it yeast. I like to think of our yeast as an old friend. Over the years, I’ve come to know what to expect from them (for the most part), but I never know if the friend might blow me away with a pearl of wisdom or crush my hopes with a harsh criticism. It’s out of my control, and therein lies the beauty of spontaneous fermentation. Like a conversation, there is back and forth, give and take. Evolution and subtle changes occur from year to year. We lose the power and insurance that commercial yeast gives us in exchange for uniqueness, for a true fingerprint of flavor. But just like Tom Oliver and the wonderful farm cideries we visited in the U.K., I wouldn’t have it any other way. I look forward to every new season and hearing what our yeasts have to say.