Step 1In large bowl or bowl of an electric mixer, stir together yeast and water. Let stand a few minutes then add warm milk, melted butter, salt, sugar and most of flour. Stir with paddle to encourage batter to become slightly elastic, but do not add too much flour. It should have the consistency of batter. Cover and let rest 45 minutes. Stir in dissolved soda, cover, and let rise 20 to 30 minutes.
Step 2Grease griddle and heat over medium-low heat. Drop batter by 1/4 cup onto griddle, spacing 2 inches apart. Reduce heat to low, cover griddle and cook crumpets until tops look dry, about 15 minutes. They will look a little gummy, but will be done; do not turn over. Repeat until batter is used up. Toast before serving.