In a pastry bowl whisk together warm milk, water, sugar and yeast. Add flour and salt and whisk until well combined. Cover with plastic wrap. Let it rise at room temperature for about 90 minutes. When ready, it will have tripled in volume, and lots of bubbles and small folds will appear on top of the surface.
Mix warm water with baking soda and mix in the bubbling starter.
Let it rise for 30 minutes more. The addition of baking soda after the first fermentation enlighten the batter creating zillion of small bubbles…
Heat up a large nonstick pan. Grease muffing rings with cooking spray in the pan and scoop out batter into each ring. After a couple minutes bang the pan to open up bubbles. After 4 minutes more, use a pair of tongs to slip the rings off. Cook the crumpets for a total of about 8 minutes on the first side, until their tops are riddled with small holes. Crumpets must be cooked on low heat. Turn the crumpets over, and cook for an additional 3 minutes. For an outstanding glossy golden brown finish, throw in some butter at the end.
Remove the crumpets from the pan, and repeat with the remaining batter until done.
Serve warm. Enjoy!