No reason why you couldn't make a sourdough english muffin, I haven't yet, but it is on my to do list.
As for the english muffin recipe...
2 1/4 cups unbleached bread flour (10 ozs)
1/2 Tbsp granulated sugar (.25 oz)
3/4 tsp salt (.19 oz)
1 1/4 tsp instant yeast (.14 oz)
1 Tbsp shortening or unsalted butter at room temp(.5 oz)
3/4 to 1 cup milk or buttermilk at room temp (6-8 ozs)
Mix all ingredients, sparing 1/4 cup of milk. form ingredients into a ball, if there is loose flour remaining, trickle in some of the remaining 1/4 cup of milk. Knead by hand or machine 8-10 mins. Dough should be tacky, not sticky, and pass the window pane test. Place in a lightly oiled bowl, roll dough to coat. Cover with plastic wrap, and allow to rise till doubled 60-90 mins.
Lline a sheet pan with parchment paper, mist with spray oil (Pam) and sprinkle with corn meal. Divide dough into 6 pieces (3 oz each) roll into tight balls, place on pan, then lightly sprinkle tops, and sprinkle with corn meal. Cover with plastic or a towel, allow to rise till nearly doubled in size and sell both out and up.
Heat a skillet to 350, also heat oven to 350. Carefully transfer them to the skillet, cook 5-8 minutes per side. They will brown quickly, but will not burn for quite a while. Transfer to oven for an additional 5-8 minutes.
Allow to cool for 20 minutes.
Sourdough. This could be short and sweet, or quite a long story...
I will assume you have a starter. (Thus the shorter explanation!)
Firm starter
2/3 cup Barm (4 ozs)
1 cup unbleached high gluten bread flour (4.5 ozs)
1/8-1/4 cup water (1-2 ozs)
Final dough
4 1/2 cups unbleached high gluten bread flour (20.25 ozs)
1 1/2-1 3/4 cups lukewarm water (12-14 ozs)
corn meal or Semolina flour for dusting
Allow Barm to come to room temp, and add remainder of firm starter ingredients, knead into a small ball. place in an oiled bowl, cover allow to ferment 4 hours, or till doubled in size. then refrigerate over night.
Remove from refrigerator at least one hour before making dough. Cut into say 10 pieces, mist with oil, and cover to warm for an hour.
Mix flour and salt, add starter pieces and enough water to bring everything into a ball. Knead 12-15 mins. Adjust flour and water as needed. Dough should be firm but tacky. Place in a lightly oiled bowl, roll to coat. Cover with plastic, let rise/ferment 3-4 hours, til doubled.
Gently cut into 2 pieces, and gently form into boules or baguettes. Proof on sheet pans, lined with parchment, thats been sprinkled with corn meal. Cover with towels or plastic 2-3 hours, or retaed overnight. Preheat oven/hearth to 500. Make use of steam tray. Using a dusted peel, transfer loaves to oven/stone, pour 1 cup hot water into steam pan, mist oven walls 3 times at 30 second intervals building additional steam. quickly close door. reduce heat to 450, bake 10 minutes, rotate loaves, bake additional 10-220 minutes, until internal temp hits 205F Loaves should sound hollow when tapped.
To make sourdough English muffins I would use the starter and make a soft dough, softer than sandwich bread or dinner roll bread. Depending on how tart you would like the muffins, you may wish to ferment longer, or retard overnight. For a hint of sour, I would increase water to the starter recipe, add the ingredients of the muffins, adjusting the flour and water to make up the volume of the Muffin recipe, being mindful to keep the finished dough, soft, and tacky, not sticky.
Also, if you have muffin rings, you can increase the water content to a little wetter then drop biscuit-like consistancy Allow to rise/form bubbles, and scoop gently into the oiled/greased rings.
Hope this makes sense!
