Sour dough Starter

How does one make a sourdough starter for bread?

Sourdough Starter
Makes about 2 cups.

4 Large baking potatoes, peeled and diced.
2 tablespoons sugar
1 cup unbleached all-purpose flour

Place the diced potatoes in a saucepan. Cover with water, bring to a boil and simmer until tender, about 12 minutes. Drain reserving the cooking liquid. Mash the potatoes, adding the cooking liquid gradually. Stir in the sugar and flour mixing well and scraping down the sides of the bowl. Cover with plastic wrap and a thick towel(this helps keep the starter warm). Set the starter in a warm place for at least 3 days, or until the mixture starts to ferment and becomes very bubbly. The starter is now ready to be used. To store place in a large plastic container fitted with a lid (quart sized yogurt containers work well) With a paring knife make 8 or so slits in the lid to allow the sourdough to breathe. Store in the refrigerator ( it will keep indefinitely if fed occasionally), but always allow the starter to warm to room temperature before using. Replenish the starter each time by reserving at least 1/4 cup of starter. Stir in warm water and flour until a thick pancakelike batter is formed. Cover the starter loosley and let it sit at room temperature until it begins to bubble then cover and store in refrigerator. NOTE: If you dont plan on using the starter for more than a month, take it out of the fridge and warm to room temp. Stir in 1/2 cup flour and enough water to make a thick batter. Let it sit at room temp until it begins to bubble, then cover and refrigerate,

Source: Pacific Northwest Flavors
I have not tried this yet, my kitchen is pretty cold so waiting till May to give it a shot. I have had this cookbook for 12 years and just found the recipe again… what can I say at least I know where to find it again now. If you try this soon please let me know how it turns out, I love good sourdough. Best of Luck and good Baking.