So it turns out I've been making sweet potato chips incorrectly my entire life. As with most things in my kitchen, I've be using the 'more is more' approach to olive oil, throwing them in the oven, and hoping for the best. I am so much wiser and smugger now.
When Coco Tribe asked me to create a recipe heroing their coconut yoghurt, my first thought was chips n dip, and crunchy chips at that. What better opportunity to pass off googling sweet potato chips as a work activity? For the unitiated, there's basically a whole corner of the web dedicated to the perfectly crunchy oven baked sweet potato chip. There were some methods I was less keen to try - washing them with egg white and liberally sprinkling them with coconut flour (am I the only person who thinks eating coconut flour is akin to eating sand?) some reasonably heavy duty science, and really, just a lot of people who love sweet potato chips. Needless to say, I learnt a lot.
Irrespective of whether you're making this recipe or you've just come here because you're currently sifting through blogs on crunchy sweet potato trial and error, here are the top tips I recommend you try implementing with all your chip creations:
1) Ensure you cut the chips to as even size as possible. Yeah yeah I know, I used to yawn at this too, and I'm yawning at myself writing it. But it definitely does help.
2) Once you've cut your chips (to even sizes of course amirite guys) soak them in a large bowl of water for at least an hour, overnight if you ceebs. This draws the starch out of the sweet potatoes. I can't remember how that helps with crunch, but it does.
3) Once you've soaked them, leave them on a tea towel to dry, and then pop them in a small plastic bag with a small amount of corn or tapioca flour, and shake them super well. This will help crunch up the edges.
4) Don't add salt until the end! This encourages them to release moisture when cooking, making 'em soggy
5) Add a teaspoon or two or vegetable oil, rather than olive, and rather than half a bottle. Olive oil has a lower smoke point compared to veg oil (I also hear grapeseed is good) so your chips will burn a lot quicker.
6) When you flip them at half time, rotate the trays from top to bottom, and spin them front to back, to allow for even heat distribution. Fancy terms for fancy food.
7) Finally, use baking paper and ensure that none of the chips are touching, and that you haven't overcrowded the oven. Too many chips = moist environment = a lot of soggy chips.
700g-800g sweet potato, peeled (roughly 2 medium sized sweet potatoes)
2 teaspoons za'atar
3 teaspoons corn flour or tapioca flour
2 teaspoons vegetable or grapeseed oil
1/2 cup coconut yoghurt (I used Coco Tribe, I find their yoghurt much more savoury than the other plain coconut yoghurts, which makes it excellente for dip)
2 teaspoons (plus extra if you're a big fan) preserved lemon juice
sea salt and torn mint, to serve
1. Chop your sweet potato into evenly sized chips, and chuck them in a big bowl of water, leaving them to soak for at least an hour. Once soaked, dry them off thoroughly with a tea towel, and preheat your oven to 180 degrees Celsius.
2. In a small plastic bag, add your za'atar and corn or tapioca flour, followed by the sweet potato chips. Shake it like a polaroid picture, or, you know, shake your chips until they're well coated in the mix.
3. Add the oil to the bag, and carry on shakin' until well coated again.
4. Line two baking trays with baking paper, and evenly spread the chips over the trays, leaving none of them touching and none too overcrowded. Cook for 15-20 minutes, and then swap the trays from top to bottom and front to back, to make sure they're cooking evenly.
5. Once you've turned them, pop them back in the oven for another 15 or so minutes, until they're crunchy and browned.
6. For a bit of extra crunch, turn the oven off, leave the door open, and leave the chips in the oven while you make the dip. To make the dip: Mix the preserved lemon juice into the coconut yoghurt and ur good to go. Give the chips a super light spray of olive oil (so the salt sticks) sprinkle over some salt and mint, and donezo.