Sprinkle yeast over lukewarm water and let it activate for 5 minutes.In a bowl of a stand mixer, combine flours and salt. Add yeast mixture to the flour and mix with a paddle attachment. Add yolk, then room temp butter. Mix until dough comes together and continue to paddle it for 5 minutes.
Remove dough, knead into a smooth ball, and place in a oiled bowl. Cover and let the dough proof at room temperature for 2 hours. The dough should double inside.
Once proofed, turn dough out onto a clean work surface. You do not need to flour the surface. Use a knife or a bench scraper to portion the dough into 8 equal pieces. Roll dough out into a ball, then flatten the dough to about 3 inches wide. Place on a sheet tray and cover with plastic wrap. Let them sit for 20 minutes at room temperature.
To cook the English muffins, get a large skillet or a griddle if you have one. Place English muffins in the cold skillet spaced out 1 to 2 inches from each other. The English muffins with puff up a bit but will not expand wider. Heat the skillet or griddle on low heat. Cook the first side for about 12 minutes. Low and slow is the way to go here, so the inside of the dough can cook all the way through. Once the dough has a nice color on the bottom, flip the dough over. The second side will take much less time since the pan is already hot. Cook for about 4-5 minutes on the second side. Repeat with the remaining dough, remember, the pan is already hot so the cook times will likely be shorter. Just keep an eye on how dark the color is getting.
The heat from the skillet should be enough to cook the English muffin through, but if you are unsure about it’s doneness then you can place English muffins in a preheated 350 degree F oven for a couple minutes just to be sure.
Let English muffins cool at room temperature, then store them in an airtight container. They’ll last for up to 4 days at room temperature and 2 weeks in the fridge. Enjoy!