Sweet, nutty spelt flour can work well in place of whole-wheat flour—but only in certain recipes.
Spelt is an ancient form of wheat that is rich in protein and minerals and was first cultivated 8,000 years ago. Because the whole berries are so big and dense and can take an hour to cook, the flour form is more accessible.
We don't have any recipes that call specifically for spelt flour, so we decided to test it out in a few that call for whole-wheat flour. In our 100 Percent Whole-Wheat Pancakes, most tasters actually preferred spelt's nutty, sweet flavor. It was also a hit in Thin-Crust Whole-Wheat Pizza with Garlic Oil, Three Cheeses, and Basil. The pizza dough was easy to stretch and exhibited minimal springback; the crust baked up crisp and chewy. But spelt wasn't as successful in Whole-Wheat Sandwich Bread; it produced squat, misshapen loaves and a crumbly crumb. Because spelt flour has fewer gluten-forming proteins than whole-wheat flour, it's even less able to give bread structure.
Our conclusion: Feel free to substitute spelt flour for whole-wheat flour in recipes in which sturdy structure isn't desirable (such as pancakes and muffins). And use it in flatbreads, because the more compromised gluten will make the dough easier to stretch. But for loaves with loft, use a recipe specifically designed to work with spelt.