Sweetness

by Farmwife Audrey

Sweet potatoes are possibly my favorite vegetable. They even have a delicious-sounding Latin name: Ipomoea batatas. Its cousins include the showy, and prolific, morning glory. Though a tropical plant from the Americas, sweet potatoes can be grown in chilly New England, and brighten our tables at Thanksgiving and well into the winter.

Ian reporting on the harvest on his tater-phone.

We’ve grown sweet potatoes at Simple Gifts Farm for years, and love to see their beautiful vines sprawling across the field, to harvest them just after the first frost, and to share their carotenous bounty with you.  This year (with a bit of help from a weeding fairy), we grew a nice crop, pulling out about 2 tons from 1/3 of an acre.

However, they do have some fussy post-harvest requirements. Immediately after harvest, sweet potatoes must be cured at high temperature (80^oF) and humidity, conditions that are not typical of October in Massachusetts. Thereafter, the tubers need to be stored at cool room temperature (55-60oF), which is much warmer than the mid-30s that most root crops enjoy.

In past years, we’ve somewhat fudged this part, curing them in the greenhouse. In many autumns, this works reasonably well, with toasty daytime temperatures and moderate nights. After curing, we have stacked crates and crates in our home basement, which is conveniently at just the right storage temperature during the winter. Not so conveniently, our basement (which is also where we send cabin-fevered children and do the laundry), gets pretty dirty, especially when the crew comes through the window to fetch a crate or two for the winter share.

Last year, however, our luck with the greenhouse-loosy-goosy-curing ran out. As house-boss, I was traumatized. I don’t really like to think about it. I didn’t want to write about it, but Jeremy thought it was a good example of how we learn and improve things each year. After last year’s late first frost, it became dismally cold. After ‘curing’ the sweet potatoes in the not-hot greenhouse, the crates stacked in our lovely basement grew horrible white mold all over them. You see, curing literally means that the heat and humidity cure the inevitable nicks and bruises that sweet potatoes acquire when harvested and disconnected from their vines. A cork layer develops, and suberin is deposited (this is for the plant nerds – suberin is a waxy material produced by the tuber’s outer root cells).  The cork layer and suberin act as a barrier to decay-causing microorganisms and to excessive moisture loss during storage. Curing also jump-starts the process of converting starch to sugar, which makes sweet potatoes sweet.

We lost most of the crop last year. Something had to change.

Jeremy, circa 1998, on a farm-built rocket ship.

This year, we have the U-Haul. Jeremy got it for cheap from a guy just over the border in Vermont, who had super-insulated it as a retrofitted walk-in cooler for his yogurt delivery business. The first time we tried, a small space heater got the inside up to 120^oF. Talk about Yankee ingenuity. It is a really ugly truck, but it is awesome.  Jeremy got a $35 thermostat for the space heater, and now can keep the U-Haul a cozy, even 80^oF.  So, we’ll cure the sweet potatoes for a week or so, then turn down the thermostat to 55^oF, where they can happily hang out with the winter squash until we all eat them.  I swear, farmers SHOULD build rockets.