Buckwheat flour can bring pleasing nuttiness to quick breads and muffins—but for moist texture, don't sub in too much.
Earthy, nutty, mineral-y buckwheat flour is distinctly recognizable in Japanese soba noodles, Russian blini, old-fashioned American buckwheat pancakes, and classic Breton crepes. We wanted to see if we could add its robust flavor to quick breads such as banana bread and muffins by swapping it for a portion of the all-purpose flour.
Two considerations: Buckwheat (which is not actually related to wheat or any other grain) doesn’t contain gluten-forming proteins, and its water-soluble polysaccharides soak up more moisture than wheat does. During our tests we monitored how those factors impacted the baked goods’ textures.
Bottom line: Buckwheat flour can add pleasing nutty flavor (and appealing tan color) to quick breads, but to ensure a moist crumb, substitute it for no more than 25 percent (by volume) of the all-purpose flour in a recipe.