1 cup milk (I used 2% but whole would be good too)
1/8 cup grapefruit juice
1/4 cup sugar
2 1/4 teaspoons instant dry yeast
1/2 cup + 2 tablespoons butter
4 cups flour
1/4 teaspoon salt
1 tablespoon grapefruit zest
*oil for frying
Warm the milk and grapefruit juice for about a minute in the microwave, stir in the sugar until it dissolves. Pour in the yeast, give it a stir (just one or two) and let this just sit and bubble for 5-8 minutes.
Melt the butter in the microwave or stove top until it’s just nearly melted. Stir in the eggs. Pour the egg mixture into the bowl of a Kitchen Aid mixer, and with the dough hook attachment turn it on low. Pour in the yeast mixture. (You can do this all by hand too if you don’t have a mixer. No worries.) Now begin adding the flour 1 cup at a time, then the salt and zest. Now turn your mixer up a notch and let it knead the dough for 8-10 minutes. It should form a loose dough and begin slapping the sides of the bowl when it’s done. If your dough seems too liquid then add another tablespoon of flour. Put the dough in a lightly greased bowl, cover and refrigerate overnight.In the morning roll out the dough (while it’s still cold) and cut out your donuts. You can use biscuit cutter, cookie cutters or the openings of jars/glasses. The dough should be 1/2-inch thick. Lay the donuts on a baking sheet, cover with a towel and allow to rise in a warm place for one hour.
Heat enough oil in a pot so that the donuts will have room to float. You want the oil to reach right around 375°F, a candy thermometer is very useful here. If you don’t have one, then you can always test your oil by using the donut holes as testers. The donuts should cook on each side for about 30-45 seconds each and then remove them to a bed of paper towels.
For the glaze (this is where most of the grapefruit flavor is!) whisk together 1/2 cup grapefruit juice and 2 3/4 cups powered sugar. The glaze will naturally be a soft pink color, if you want more add a little red and yellow food coloring.Dip the cooled donuts in the glaze and set them on a rack above a baking sheet lined with wax paper or paper towels (for easy clean up). You can dip twice, letting the glaze set in between each coat of glaze.