Preheat your oven to 250°F (120°C). Spread the 1/2 cup of baking soda in a thin, even layer on a small, foil-lined baking sheet.

Bake for 1 hour. This process converts the sodium bicarbonate into sodium carbonate, a stronger alkaline salt that gives ramen noodles their signature color, flavor, and texture. Let it cool completely. Store the leftover baked soda in an airtight container for future batches. Be careful not to touch it with bare hands as it can be a mild irritant.

In a small bowl, dissolve 4g of the cooled baked baking soda and 4g of salt into the 160ml of warm water. Stir until fully dissolved. This is your alkaline water.

In the bowl of a stand mixer (or a large mixing bowl), whisk together the 400g bread flour and 4g vital wheat gluten (if using).

With the mixer on low speed (using the dough hook), slowly drizzle in the alkaline water. The mixture will look very dry and crumbly, like small pebbles. This is normal for a low-hydration ramen dough. Continue mixing for 2-3 minutes until it comes together into a very shaggy mass.

Turn the dough out onto a work surface (do not flour it) and knead by hand for 10-15 minutes. The dough will be extremely stiff and difficult to work with initially. Use the heel of your hand and your body weight. Knead until it forms a cohesive, firm, and slightly smoother ball. Alternatively, you can place the crumbly dough in a sturdy zip-top bag, seal it, and knead it by stepping on it with clean feet for a few minutes.

Wrap the dough tightly in plastic wrap or place it in a sealed bag. Let it rest at room temperature for at least 1 hour, or up to 4 hours, to allow the flour to fully hydrate and the gluten to relax.

After resting, the dough will be more pliable. Unwrap it and divide it into 4 equal pieces. Keep the pieces you aren't working with covered to prevent them from drying out.

Take one piece of dough and flatten it with your palm or a rolling pin until it's thin enough to fit into your pasta machine on its widest setting. Lightly dust the dough with flour if it feels sticky.

Pass the dough through the widest setting. Fold the sheet into thirds, like a letter, and pass it through the widest setting again. Repeat this folding and rolling process 2-3 more times. This step develops the gluten and creates a chewier noodle.

Continue passing the sheet through the roller, reducing the thickness one setting at a time, until you reach your desired thickness (usually setting 3 or 4 for ramen). Do not fold the dough during this stage. The sheet will become very long.

Switch to the spaghetti or fettuccine cutter attachment on your pasta machine and run the sheet through to cut the noodles. As the noodles emerge, catch them and immediately toss them gently with a generous amount of cornstarch or potato starch to prevent sticking. Form them into small nests.

Bring a large pot of water to a rolling boil. Do NOT salt the water, as the noodles are already salted and alkaline.

Gently shake off any excess starch from the noodle nests and drop them into the boiling water. Stir immediately to prevent clumping. Cook for 90 seconds to 3 minutes, depending on thickness, until they are al dente with a pleasant chew. Taste one to check for doneness.

Drain the noodles immediately using a colander or spider strainer. Do not rinse. Serve right away in your favorite hot ramen broth with your desired toppings.