In a large bowl, stir yeast into 1 cup warm water.

Beat in flour, sugar, melted shortening, and salt to make a dough.

Turn dough onto a floured surface and knead for 5 minutes.

Place dough into a greased bowl.

Let rise in a warm place until doubled, about 1 hour.

Punch down dough and divide into 12 equal-size pieces.

Roll each piece into a rope 18 to 20 inches long.

Preheat oven to 375 degrees F (190 degrees C).

Grease a baking sheet.

Shape each rope of dough into a pretzel on the prepared baking sheet.

Let pretzels rest for 5 minutes.

Beat egg yolk with 1 tablespoon water in a small bowl.

Brush yolk mixture over each pretzel.

Sprinkle each with coarse salt.

Bake in the preheated oven until pretzels are golden brown, about 15 minutes.