Preparation

• Grease or line a 9-inch x 5-inch loaf pan and set it aside.
• In a stand mixer bowl, place flour blend, xanthan gum, yeast, cream of tartar, and sugar. Whisk with a handheld whisk. Add salt and whisk again.
• Add milk, butter, vinegar, and egg whites, and mix on low speed. Scrape down sides as necessary.
• Increase mixer speed to medium-high and mix for about 3 minutes until thick and smooth.
• Scrape the dough into the prepared pan and smooth the top with a wet spatula.
• Cover with lightly oiled plastic wrap and allow to rise in a warm place for 30 to 45 minutes.
• Preheat the oven to 375°F near the end of rising time.
• Remove the cover and optionally slash the top of the loaf. If using seeds, brush with melted butter and sprinkle them on top.
• Bake for 45 minutes to 1 hour; remove lid if using a Pullman pan after 40 minutes.
• Ensure the internal temperature reaches about 205°F, then allow to cool for 10 minutes before transferring to a rack.
• Slice into 10 equal slices when fully cooled.