Mix the whole wheat flour, potato starch, and flaxseed meal in a bowl, and set aside.
Place the water, orange juice, and maple syrup in a microwave-safe bowl. Heat the preparation first for 1 minute, and then for an additional 15 seconds every time, until reaching 100 to 110° F (38-43° C). It has to be warm but not hot otherwise, it can kill the yeast. You can also use a saucepan over medium-low heat instead.
Pour the warm liquid into a large bowl, add the yeast, and stir until combined. Let this preparation rest for about 5-10 minutes until it looks foamy. With this step, we make sure the yeast is activated and not expired*.
Add the whole-wheat flour, potato starch, and flaxseed meal into wet ingredients. Using a rubber spatula or wooden spoon, combine all the ingredients until you get a sticky dough that also pulls away from the sides of the bowl. If the dough is still sticking and not separating from the bowl, add no more than 2 tbsp of flour at a time. If it's to dry, add 2 tbsp of water at a time. Now add the salt if you are using it, and combine.
When the dough ball is formed, it's time to begin kneading: folding, rolling, and rotating it. Since the dough is a little bit sticky, I usually prefer kneading it in a big bowl. You can put a little bit of flour in your hands or water. Also, be free to use a lightly flowered surface or stand mixer**. Continue kneading until the dough looks very smooth, elastic, bouncy, but still a little bit tacky (around 10 minutes).
Cover the dough with a damp towel or paper towel. Let it rest and rise for about 1 hour *** in a warm area. The dough should roughly double in size.
Prepare a 9x5 loaf pan. I prefer silicone ones to avoid sticking. However, I've used other pans without oil, just adding a piece of parchment paper at the bottom (you can also use a lightly greased pan).
After the dough has risen, gently punch the dough down a couple of times to release air bubbles. Transfer the dough to a lightly floured surface, form a rectangle with your fingers, fold both sides to the center, roll it from the top into an oval shape and place it into the loaf pan. Cover and let it rise again in a warm place, this time for about 30 to 45 minutes.
Preheat the oven to 350° F (190° C).
It's time to bake when the dough is about an inch (2.5 cm) above the loaf pan (don't let the dough rise more than that). If using, brush the top with aquafaba and add the oats/seeds. Place on the middle rack and bake the loaf for 35-40 minutes or until golden brown (the loaf sounds hollow when you tap).
Remove from the oven and allow to cool a while before removing it from the pan (around 5 minutes) and placing it on a cooling rack. Let it cool completely before slicing for the best results.
Enjoy your homemade bread for breakfast, sandwiches, toast, and more!