What is the difference between purple sweet potatoes and ube?
They are not the same. Purple sweet potatoes are a type of sweet potato with purple flesh and a mildly sweet, earthy flavor. Ube is a purple yam with a different texture and a flavor that is often described as vanilla-like, coconutty, or nutty (and generally more dessert-leaning). If your store label says “purple sweet potato,” that is what this recipe is built for.
Do purple sweet potatoes taste different?
Yes, a little. They are usually less sugary than orange sweet potatoes and can taste nutty and slightly dry in a good way, like roasted squash meets chestnut. That is why a creamy sauce works so well here.
Why are my wedges not getting crispy?
The usual suspects are crowding (they steam), not enough oil, or a pan that never gets truly hot. Spread the wedges out in one layer, roast at 425°F, and use a large sheet pan. If needed, use two pans.
Should I peel purple sweet potatoes?
You do not have to. The skin is edible. I like to leave it on for less prep and more texture. Just scrub well.
Can I make these in advance?
Absolutely. Roast the potatoes up to 4 days ahead and keep the sauce in a jar. Reheat the potatoes in the oven or air fryer, then drizzle right before serving. Heads up: the edges will soften a bit in the fridge, but they crisp back up nicely with dry heat.
Any allergy notes?
Tahini is made from sesame. If you are cooking for someone with a sesame allergy, swap the drizzle for a limey yogurt sauce or a simple squeeze of lime plus olive oil and salt.