News Article for October 5, 2009, from LSU AgCenter County Agent Kenny Sharpe:
Sweet potatoes are a fall favorite. Many of us like them baked, and as the weather cools, it makes it easier to justify turning on the oven.
Fall also coincides with the harvest of the new crop of sweet potatoes. The harvest can start as early as August on the very early planted potatoes, but most of the home garden potatoes are harvested in September, October and into November.
Wet weather is not the friend of a sweet potato producer who needs to harvest potatoes.
The keys to good potatoes that are sweet are in the varieties and in the curing. Some of the most popular sweet potatoes today are the Beauregard variety, which is of good quality and sweet. They also are predictable in production, being ready to harvest in just 90 days from planting. This will yield a high percentage of No.1 potatoes which are 3 to 9 inches long, 1¾ to 3½ inches in diameter and weighing no more than 18 ounces. If allowed to go longer, they will continue to grow, and you will get some pretty big potatoes that we usually call jumbos.
The Beauregard potato is a nice looking potato that has a light rose skin and good tasting orange flesh.
Curing is of utmost importance in bringing out the sweetness of any sweet potato. When the potatoes are first dug, we refer to them as green potatoes, and they will not be very sweet if baked.
The first phase of curing is accomplished quickly. The potatoes are stored at 85-90 degree F and 85-95 percent relative humidity for four to seven days. This will heal all of the skinned spots and cuts on the outside of the potatoes. Curing improves the appearance of the potatoes and reduces the possibility of diseases in storage.
Next, the potatoes are placed in storage. Ideally, the potatoes are stored at 55-60 F and relative humidity of 85-95 percent for seven to eight weeks. During this time, the sweet potatoes will convert the starch in the potatoes to sugars, making the potatoes sweet when baked.
If you are purchasing sweet potatoes and do not know about their curing, I would suggest you buy some earlier than you need them. This would allow time for them to cure after you purchase them. I like to buy them in October for use by Thanksgiving if I do not know the source of the potatoes. It generally takes a few weeks to get potatoes into the market, so four to six weeks should allow plenty of time for maximum sweetness to develop.
Just be sure to store the potatoes in a cool place but not in the refrigerator. Low temperatures will reduce the quality and cause the potatoes to develop a hard center.
For additional information on this or related topics, contact Kenny at 225-686-3020.