As winter set in this January, Sarah Kieffer recalled how it snowed for eight months last year in her hometown, Minneapolis. For weeks on end, the temperature dipped below minus 20. Surrounded by grayness, she baked blueberry muffins for the cheer of their bright pops of blue.
“It’s like when the hobbits got to Mordor, and Sam looks up and sees a bright shining star, and has a little bit of hope,” she said. “That’s what a blueberry muffin feels like in February.”
Ms. Kieffer, the author of “100 Morning Treats” (and a self-described “super nerd”), grew up with box-mix muffins and has since created from-scratch versions for her popular baking blog and cookbooks. She prefers muffins that aren’t as hefty as some bakery ones and lightens the texture with almond flour.
This simple lemon blueberry muffin uses only all-purpose flour and relies on yogurt for an unparalleled airiness. Even though muffins as dense as coffee cake are delicious, they’re not quite right for a season of heaviness (wool coats, beef stew, existential crises). This is when you want bites of sunshine, bites that feel like soft breezes.
Yogurt is the secret to achieving optimal muffin fluffiness and also gives the not-too-sugary lemon cake batter even more tangy complexity. If you don’t already keep plain whole-milk yogurt in the refrigerator, now is a good time to start. It can be the base for granola breakfasts, but also for quick savory sauces, marinades and dressings for lunch or dinner.
“The versatility is its best feature,” Cheryl Sternman Rule said. As the author of “Yogurt Culture” Ms. Rule celebrates its use across cuisines and especially in baking.
Yogurt is made by fermenting milk with a bacteria-based starter culture. That culture then produces lactic acid, which causes the milk protein to thicken into a creamy, slightly tart mixture. When whole-milk yogurt is used in muffin batter, it adds richness but also keeps the texture light because of its acid and liquid content.
To ensure a high rise for muffins that are still sturdy enough to stand with pockets of juicy berries, both baking soda and baking powder are whisked into the dry ingredients. When baking soda, which is a base, hits the acid of yogurt, it quickly releases carbon dioxide gas and makes the batter bubble up quickly. That gives it both airiness and an extra-big muffin top. Baking soda also promotes browning, so that muffin slope burnishes to a deep coppery amber.
Because baking soda neutralizes acid, baking powder, which is also a base but includes acidic cream of tartar, is also used in the batter. Baking powder’s little bit of acidity both bolsters the tartness of the yogurt and lemon juice in these muffins, and makes the crumb tender. Baking powder works more slowly, giving the batter a steady lift to ensure a perky, soft muffin.
Yogurt is ideal for its balance of natural sweetness and measured sourness, but mainly because it means you don’t have to make another trip to the store, especially in slush, ice or any messy wintry mix. If you happen to have only plain Greek yogurt or labneh on hand, simply thin it with enough milk to make it as runny as plain yogurt. Sour cream can be swapped for the yogurt and will give you a finer crumb. Buttermilk works too, but may take longer to bake through.
Whichever ingredient you use, you’ll be rewarded with a breakfast treat that feels warming and sustains until real warmth comes back around. As Ms. Kieffer said, “It’s like a little tiny beacon of joy.”
