In a small bowl, whisk together the warm water (110℉), sugar, and yeast. Let it sit for 10 minutes until frothy. Place the frozen wild blueberries in a microwave-safe bowl. Microwave for 30 seconds to thaw the blueberries before stirring in the additional sugar, lemon zest, and salt.

Add the frothy yeast mixture and blueberry mixture to the 2 cups of flour in a mixing bowl and stir until the dough begins to come together. Turn the mixture onto a lightly floured countertop and knead until a smooth dough forms, adding up to ¼ cup more flour until the dough is slightly tacky but not too sticky to work with. Cover and let rise in a warm place for 1 hour until doubled in size.

Once risen, punch down the dough and separate into 6 equal pieces. Shape each piece of dough into a bun shape by gathering the dough into a seam on the bottom. Then, pop a hole with your thumb through the center of the bun and roll it around using both index fingers to make the hole bigger. Repeat this process with all 6 pieces of dough and place them on a parchment paper-lined baking sheet. Cover and let rise for 15-30 minutes.

While the bagels are rising, preheat the oven to 425℉ and boil water at least 3 inches deep in a large pot or Dutch oven to boil the bagels in. Stir 1 tablespoon of brown sugar into the boiling water. Boil the bagels at a rolling boil, a few at a time, so that they don't crowd in the pot. Boil for 1 minute on each side. Gently remove from the water and place back onto the parchment paper-lined baking sheet.

Bake the boiled bagels immediately in the preheated oven for 10-14 minutes or until the tops are browned. Let cool for 5 minutes before carefully transferring to a wire rack to finish cooling so that the bottoms do not become soggy.