I was sent to Atwater, CA on a writing assignment for Distiller Magazine to interview David Souza, a 4th generation sweet potato farmer who developed an innovative way to use his excess sweet potato and rye crops—premium spirits. Yup! David is the first craft distiller in the US to make sweet potato vodka, and the only one making sweet potato whiskey (blended and 100% Merced Rye whiskey), gin and liqueur.
Why make sweet potato vodka and spirits? Aside from liking the challenge, turns out grinding and cooking sweet potatoes into a mash is a great way to get rid of the less valuable “jumbo” sweet potatoes typically sold as cattle feed, or to large commercial processors who package them up as the sweet potato fries you see in your grocer’s freezer.
Aside from nearly melting in the 106° F heat the day I was down there, I got to tour some of Souza’s 2,000-acre portfolio of sweet potatoes, rye, and almond groves and I learned a ton. Did you know almonds are at the center of these pods?
Once dry, the pod bursts open and they use a tree shaker to grab the trunk of the almond tree and shake the open pods to the floor for collection. Apparently Almond trees need about 65 gallons of water every day! Amazing.
During our time together David shared a lot about his family history and how they’ve been farming in California’s central valley for over 100 years.
It was only just ten years ago that David Jr. Jr. Jr. (yeah, I think that’s right) realized he could turn their worthless cover crop (the Merced rye) into 100% rye whiskey which is all the rage these days, and use their mainstay (different varietals of sweet potato) in premium spirits.
Processing sweet potatoes
Sweet potatoes grow best just below the surface.
The crews drive these long tractor like machines down the rows of sweet potatoes and these conveyor belts with blade pulls the sweet potatoes out of the ground and up onto a sorting line. It’s all one contiguous effort and the crews sort the different size roots (that’s what sweet potatoes actually are) into different wood crates. The jumbo sweet potatoes get put on a shelf above the conveyor belt.
Then they’re brought to another facility where they’re washed, weighed and boxed for storage or shipping.
Seeing the entire process from beginning to end was really neat!
Making Sweet Potato Spirits
Depending on the spirit they’re making at the time, they use a proprietary blend of sweet potato varietals and grind them and cook them at high temperatures with certain enzymes to break down the root vegetable starches until they have a soup. Then they go through the typical distilling process using one of their two Alembic copper pot stills before chilling, potentially rectifying the spirits to 190 proof in a higher column, diluting, and either barrel-aging (for the whiskeys and liqueur), or going straight into the bottle for the vodka or infusing the neutral spirits with botanicals for their gin.
Sweet potato pie recipe
David asked me if I wanted to take a few sweet potatoes home, and I said “sure, why not,” thinking it would be good to try the product I’d just spent the day talking about.
And when I was about to leave, he reminded me to take a few spuds and loaded two 40 lbs boxes of sweet potatoes (Bonita whites and Orange sweet potatoes) into the trunk of my car.
“Oh I don’t need that many,” I said, thinking I could never get through 80 lbs of the root vegetables. But he assured me that it was easier to just give me the two boxes than just pull a few out, because that would require someone to replenish and weigh them again, which was just too much hassle.
So I drove home to San Francisco, and for the next two weeks, I gave a bag of sweet potatoes to everyone I crossed paths with—even the mailman. That’s after roasting and pureeing nearly 20 lbs of them myself, which are in the freezer for future use.
I’ve enjoyed the sweet potatoes in a vegetarian lasagna with brown butter and sage. I also used them to develop this delicious sweet potato pie recipe—the perfect fall dessert.
This sweet potato pie recipe turned out really well. It’s not too sweet, but just sweet enough, and once you try it, you’ll want to prominently feature it at your next Thanksgiving Dinner.
Roasting your sweet potatoes
Can you use canned sweet potatoes for this recipe? Sure. Is it going to be as delicious and satisfying as if you roasted them yourself? No! Roasting sweet potatoes is really easy. Rinse them with water to get any dirt off. Wrap them tightly with aluminum foil, making sure to cover them completely.
Place them on a baking sheet with parchment paper for easy clean up and roast them at 450°F for about 45 mins or until you can squeeze them and feel that they’re soft.
Then just let them cool outside the oven, and when you can handle them, open up the foiled pouches and the skin will just peel off.
- Pie crust (store bought or made from scratch)
- 1 ¾ cups of sweet potato puree (I like to mix white and orange varietals)
- 3 large eggs
- 1 tsp cinnamon
- 1 tblsp minced fresh ginger
- ½ cup granulated sugar
- ¼ cup packed light brown sugar
- 1 ½ cup canned evaporated milk (can also use heavy cream if you’d prefer)
- ¼ tsp fresh ground nutmeg
- ⅛ tsp ground cloves
- ½ tsp vanilla extract
- ½ tsp salt
For the topping:
- 3 tblsp melted butter
- ⅓ cup light brown sugar
- ⅓ cup flour
- ⅔ cup pecan pieces
- ¼ tsp cinnamon
Make your pie crust ahead of time so it’s cooled before you start making the sweet potato pie. If you’re using a frozen or store bought crust, just make sure it’s been par-baked.
Preheat your oven to 350° F.
Combine all the ingredients for the sweet potato pie in a food processor and puree until nice and smooth.
Fill your completely cooled par-baked pie crust (I used Martha Stewart’s recipe for pâte brisée) with the sweet potato mixture and gently smack the pie on the counter a few times to release any bubbles.
Combine the ingredients for the crumble in a small bowl. You can use a food processor if you’d like to get the mixture fine and uniform, but I tend to like it a little more rustic and crunchy so I use a dough cutter.
Just make sure the butter and the flour are combined so you don’t have any crumbles of white flour left.
Sprinkle the pecan crumble mixture over the top of the sweet potato pie and place it on a rimmed baking sheet lined with parchment paper. This will make for easy clean up and protects you in case some of the pie filling spills over the edge of the crust.
Bake for 50-60 minutes until the sweet potato pie is slightly set around the edges and jiggles a little in the center when you shake it.
Let the sweet potato pie cool completely on a wire rack before you cut into it
Think about serving your sweet potato pie with candy cap ice cream, maple ice cream, or a good old-fashioned scoop of your favorite vanilla. Or, just top it with a dollop of lightly sweetened whipped cream.