Have you ever demolished a large bag of Sour Patch Kids or Starbursts and decided to stop because you were just full? If you’ve ever struggled with the serious illness of candy addiction, the answer is no. On the rare occasion that I would relinquish a bag of fruity candy prior to inhaling all its contents, it was only because I was no longer able bite down without hitting a swollen taste bud. Never because I was full.
Come to find out that “neverfull” feature of the artificial fruity goodness is actually a byproduct of how my body digests the addictive morsels. So, really, it’s not my fault, it’s the fault of my metabolic pathway and how my body deals with fructose overload. While a little bit of fructose is okay, the standard American diet includes way too much of it. HFCS (high fructose corn syrup) gets a fair amount of negative press but it’s really only nominally more harmful to your body than plain old white sugar, which is half fructose.
All this fructose is problematic for your liver, which is where your body processes it for use. When it gets taxed beyond its capacity from that 20-oz. Mountain Dew, all that extra available fructose runs amok in your bloodstream, turning into nasty triglycerides. The process by which your body metabolizes glucose suppresses ghrelin, the hormone that tells your body you’ve eaten enough. Fructose metabolism allows ghrelin to stay high, which can be disastrous in a person suffering from a dysfunctional metabolism. Furthermore, all those extra triglycerides also mess with leptin secretion, another hormone that regulates satiety.
All that to say that foods high in fructose don’t make you full. It’s fine for mouth-exercise but if you want your body to feel satisfied from a meal or snack, minimize the fructose.
A quick bit of online research can tell you the fructose content of foods. You can see that sweet potatoes are pretty awesome, containing an isocalorically similar amount of fructose to spinach and mushrooms.
Before I get too far into this recipe, I just want to say that these should not be consumed while on the Belly Fat Cure or another very low sugar diet. Yeah, sweet potatoes are loaded with nutrients and nearly free of fructose, but they do have plenty of sugar. These are an awesome post-workout snack and they are perfect as a carb source for someone trying to maintain a moderate carb diet or have a healthy, grain-free portable carbohydrate. They would also be a great snack for kids but I’ll tell you right now you’re not going to want to share them.
That disclaimer out of the way, lets be real and admit that snacks are pretty awesome. But, having kicked your previous sugar demons to the curb, you don’t want to reintroduce the same crap that sent you down the road toward metabolic dysfunction in the first place. You’d prefer a carb source that is grain-free, but it has to be yummy. Rewarding even.
Sweet potatoes? You mean the things that people make with marshmallows and pineapple for Thanksgiving? They’re okay I guess but not something I’m dreaming about.
After your first taste of crispy-chewy sweet potato jerky, you will never look at sweet potatoes in the same way. You will get excited when your Costco has the big 10 lbs box for $6.99. You will feel a little silly buying 4 boxes. You will get weird looks from the checkers. But they keep very well in the garage and to answer the checker’s question, “oh yes, you’ll get through all of them.”
This is a very simple recipe. All the food you need is right here.
If you’re avoiding dairy then you can use coconut oil (virgin, not expeller-pressed, please). It’s good, but not at good as Kerrygold butter. Sorry dairyphobes, it’s just not as good. Besides, it’s only dairy fat so you probably will tolerate it just fine anyway.
I’m sure someone is saying to themselves, “hey, aren’t those yams?” Actually no, they are just orange sweet potatoes. From what I gather it’s rather unlikely that anyone reading this blog has every had an actual yam unless they’ve spent some time overseas. It’s an error perpetuated by grocery stores that don’t want to confuse people by having two type of sweet potatoes. It’s one of those things that so many people believe that you actually are more likely to confuse people by using the accurate term than the wrong one. Like if I told you to to peruse this post prior to trying to make these, most people would believe I am instructing them to perform a cursory review of the material when the word peruse actually means “to study carefully”. But it’s been used inaccurately for so long that it’s best just avoided. Enough of that. Just make sure you get the orange sweet potatoes; the yellow ones don’t work in this recipe because they break apart too easily.
The first step is to bake the sweet potatoes.
I strongly suggest putting foil down under the sweet potatoes. Unless you like the smell of your oven’s self-clean cycle. I’d actually oversize the makeshift foil pan to create a lip on the front, back and sides. One of the Costco boxes fills one of the trays on my oven. Since they are a bit on the large size, I’ll typically bake one tray at 350 for an hour. If I’m going to rock two trays then the baking time goes up to 80 minutes.
After the requisite time has elapsed, I’ll crack the oven and let them cool down for a few hours. One thing I like to do if my schedule permits is let them cool overnight in the oven. You should be prepared to deal with them earlier in the day though. You wouldn’t want them to get moldy.
Once they’ve cooled the skins should come off easily. Pile up the skinned potatoes in a large baking dish, cover with plastic and refrigerate until you are ready to cut them up. You could start cutting into them right now but I prefer to do it when they are cold.
Note that this amount will produce many pans of sweet potato jerky. Another name for this is a dish full of awesome.
Now you need to slice them and arrange them on a baking sheet. I also like to use one of those silicon liners (something like this) to make removal of the finished product easier. I cut them about 1/2 a centimeter thick. You’re going to want a uniform thickness to allow for even cooking. I find 1/2 cm. gives me enough potato to keep it from becoming a mess when I transfer pieces to the pan.
Keep in mind that the more uniform the thickness, the more consistent the results will be when you bake them. If they are all over the map in terms of size, you’ll end up with some magically crunchy-yet-chewy jerky and some less-than-stellar crunchy ones and some not-as-good-as-it-could-be soft ones.
Now, melt your butter or coconut oil and paint the potato slices with fat using a pastry brush. They will glisten with goodness. All that glucose plus some hard-to-find medium chain triglycerides (coconut oil) or CLAs (pastured butter). This is truly better living through science.
Then back to the oven it goes for the “drying”. This is the tricky part.
No seriously. Prepare for a little bit of frustration as you learn your oven’s “hot spots”. The most common refrain when I hand these out at the gym or talk to people about them is, “yeah I’ve tried to make these a couple times and just can’t get it to work right.” Many people give up. I’ve cooked hundreds of pans of these and burnt more than a few of them. There is a learning curve; be prepared to climb it.
Many people have suggested that a dehydrator would work well. It’s possible, but I haven’t tried it. Part of the magic is the combination of crispy potato outside cooked in butter and the chewy not-cooked-quite-as-much middle. A dehydrator would likely produce a uniform texture and may make it a lot easier, but I’ve figured it out and wouldn’t want to settle for second best.
I’ve experimented with various time and temperature domains in order to find something repeatable. Ovens will vary, but if you have a convection oven, you can use 40 minutes at 365 as a starting point. I usually cook 3 trays at a time in my convection oven. At the initial buzzer, only the ones at the very outside of the pans are done, with the pan in the middle lagging behind the upper and lower pans. I’ll typically take off the finished ones, move the others from the middle to the outside and return to the oven for about 10 minutes. Occasionally I’ll need to put a few stragglers on one pan back in for a third stint in the oven of 5-8 minutes, but usually I’ll just let those ones turn into chewy ones.
Keep in mind that the thinner you slice them, the shorter the cooking time. The more consistent you slice them and the more evenly your oven heats, the more consistent your results will be.