Remove the loaf pan from your bread machine. Attach the mixing paddle and set the pan aside.
In a medium-size mixing bowl or a large liquid measuring cup, place the warm milk, unsalted butter, vinegar, and eggs, and whisk to beat the eggs and combine fullly. Set the wet ingredients aside.
In a medium-size mixing bowl, place the flour blend, xanthan gum, tapioca starch, cream of tartar, baking powder, granulated sugar, and salt, and whisk to combine well. Set the bowl aside.
Pour the wet ingredients into the loaf pan with the paddle attached.
Place all of the whisked dry ingredients (without the yeast) on top of the wet ingredients in a single even layer. Do not mix at all.
Use a clean, dry finger to create a small well in the center of the dry ingredients, shallow enough not to reach the wet ingredients but deep enough to hold the yeast. Pour the yeast into the well.
Plug in and set up your bread machine for use.
Consult the manufacturer's user guide to toggle to the "homemade" setting, if possible, and apply these settings :• 1.5 pound loaf setting• 20 minutes of mixing/keading (one knead cycle only)• 1 hour rising time (one rise only)• 1.5 hour baking time• Dark crust setting if available
Alternatively, use your bread machine's "gluten free" setting.
Place the bread pan securely in the machine and close the lid. Press the start button.
Listen for when the mixing/keading cycle is done or nearly done, and use a silicone spatula to scrape down the sides of the pan to mix in any loose flour.
Wet the spatula, and smooth the top of the raw dough into an even layer.
Close the lid and allow the bread to rise fully and bake for 1 hour.
Open the lid and use an instant read thermometer to check the internal temperature at the center of the loaf. It should read at least 205°F.
If your machine browns the top, let it bake until the top is browned and feels firm on top (another 15 to 20 minutes).
Remove the loaf pan from the machine as soon as the bread is done baking. Turn it out of the pan onto a wire rack and carefully remove the paddle from the bottom center as soon as you are able to handle the loaf.
If your machine doesn’t properly brown the top of the loaf, place the unmolded loaf on a baking sheet in a 400°F oven for about 10 minutes.
Allow to cool fully for at least 1 hour and ideally 2 hours before slicing horizontally and serving.
Notes
Bread machineThere are a lot of bread machines today that are relatively reasonable in price and have a "homemade" setting, which allows you to control every stage of the process. I have used and recommend the KitchenArm 29-in-1 SMART Bread Machine, but I'm not really partial to it.Flour blend choicesMy favorite gluten free flour blends are Better Batter's original blend gluten free flour and Nicole's Best multipurpose blend (with 3 teaspoons added xanthan gum). King Arthur Flour's gluten free bread flour should also work here, but would likely make a slightly more dense loaf. Their Measure for Measure blend will not work. Caputo Fioreglut flour would probably work to make a somewhat shorter loaf that doesn't brown very well. I don't recommend Bob's Red Mill 1-to-1 Gluten Free Baking Flour here, but I can usually use in somewhat effectively in yeast bread by adding an extra 1 1/2 teaspoons xanthan gum to the dry ingredients.I don't recommend Cup4Cup any more, especially for bread baking. To make your own blend using one of my “mock” recipes, please see the all purpose gluten free flour blends page.Whatever you choose, please measure your ingredients by weight, not volume (cups) for consistently good results.Instant yeastInstant yeast is also called rapid-rise or breadmaker yesat.To use active dry yeast instead of instant yeast, use 10 grams instead of 8, and mix it into the milk mixture. Let the mixture sit until the yeast begins to bubble, then continue with the recipe.