I have never used milk or yogurt for sourdough starter (mine started with starter purchased from King Arthur Flour)... I would recommend getting some starter then just use flour and water. But I do make yogurt. If the milk is too hot, it will curdle yogurt. I let the milk cool to 110F, then add a ladle of milk into the yogurt in a slow stream while whisking, then add the yogurt back to the bulk of the warm milk.
Here is a starter for the sourdough challenged. You will be baking sourdough bread within a week.
I've used Carl's Friends Oregon Trail Sourdough starter for about 5 years. It's really good, very vigorous. But I wanted to try something else.
I tried several times to create a starter from wild yeasts, even using the pineapple juice method. I tried rye flour starter. Either it wouldn't work, or I would get a really weak starter that could barely raise itself. Frustrating.
In desperation, I decided to try something else. I read years ago in Sunset magazine about a pure yogurt starter. That sounded interesting, but I didn't want to use a pure yogurt starter that required feeding with yogurt.
Here's what I came up with. I have started this sourdough starter several times, as an experiment, and each time, within 5-days, I was baking sourdough bread. The sourdough bread was every bit as good as bread from Carl's starter.
I use buttermilk, yogurt, a little rye flour, a pinch of instant yeast and all-purpose flour to get the sourdough starter going, but I only feed the starter all-purpose flour and water to sustain it.
I give the starter all of these cultures to start with and let them fight it out. In the end, it makes a starter as good as Carls Oregon Trail starter. It's consistent. You can reproduce sourdough starter on demand within a week.
Buttermilk Yogurt Sourdough Starter
1 cup Buttermilk, with live cultures (check the label)
3 Tbsp Plain Yogurt, with live cultures (check the label)
1 cup All-Purpose Flour
1 Tbsp Rye Flour
pinch of Instant Yeast (1/16 tsp)
Mix well. Allow to sit on counter in loosely covered container for about a week. Tupperware, Gladware, etc is fine.
Feed daily 1/2 cup All-Purpose Flour and 1/4 cup Water. Mix well. Discard excess, if necessary. It will bubble up and overflow sometimes, so I keep the container sitting in a pie tin or dinner plate to catch any overflow.
After about 5 days of feeding, the starter will smell sour and be very vigorous and bubbly. It's ready to make sourdough bread.
Just like any new starter, it's not real sour at first, but that will develop over time. To encourage more sour, keep it hydrated more like a dough and less like a batter. Also, a tablespoon or two of rye flour in the feeding encourages more sour.
I use 1/2 a cup of the starter to make a loaf of sourdough bread.
When active, bubbly and sour smelling, store covered in the fridge if you are not going to make some bread.
Revive Sourdough Starter and make a loaf of bread at least once a week.
To revive, remove starter from the fridge, stir in 1/2 cup of all-purpose flour and 1/4 cup water. Bring to room temperature and allow starter to get bubbly. Use 1/2 cup to make bread.
If you neglect it and the starter dies, it's not such a big deal. You can have a new starter in about 5 days.
Here's the sourdough bread I usually make from the 5-day sourdough starter:
Buttermilk Sourdough Bread
This bread machine recipe makes a nice loaf of buttermilk sourdough bread, totally in the bread machine. The sourdough starter and buttermilk combine to make really good tasting loaf of sourdough bread.
1 cup (240g) Buttermilk
1/2 cup (125g) Active Sourdough Starter
1 2/3 cups (200g) All-Purpose Flour
1 1/2 cups (200g) Bread Flour
1/3 cup (40g) Whole Wheat Flour
1 Tbsp (15g) Rye Flour
1 Tablespoon (15g) White Granulated Sugar
1 1/2 teaspoons (10g) Table Salt
2 Tablespoons (30g) Olive Oil
Add Buttermilk and Active Sourdough Starter to bread machine, mix well. Add the All-Purpose Flour, Bread Flour, Whole Wheat Flour, Rye Flour, White Granulated Sugar and Table Salt to the bread machine.
Sprinkle Olive Oil on top of flour.
Set Bread Machine to MANUAL DOUGH CYCLE. (For a Zojirushi Bread Machine
use the MANUAL CYCLE set to Rest 30 minutes and Knead 20 minutes.)
During first few minutes of kneading, adjust dough, as needed, with flour or water to form a smooth, firm, non-sticky, non-crumbly dough.
When the kneading has stopped, unplug the bread machine. Remove the mixing paddles and form dough into loaf by tucking it in on itself from the bottom and press the dough evenly into the bottom of the bread pan.
Spray the dough to coat with a non-stick cooking spray (this will help to keep it from drying out on top.) Close the lid of the bread machine and let dough rise for 8 to 12 hours.
After 8 to 12 hours, when the dough has risen to within about 1-inch from the top of the bread pan, start the MANUAL BAKE cycle.
For a Zojirushi Bread Machine, run a MANUAL CYCLE to bake for 1 hour and 10 minutes.
When bread is done, remove from bread baking pan and allow to cool before slicing.
Makes a 1 1/2 pound loaf.
** To make by hand **
-Combine ingredients, knead for 10 minutes.
-Form dough into loaf and place in a greased 9x5-inch loaf pan. Coat top of loaf with cooking oil. This prevents the dough drying out during the long rise.
-Allow to rise in a warm place for about 12 hours, until dough is about 1/2 inch above the edge of the loaf pan.
-Pre-heat oven to 400-F. Bake about 60-minutes, or until exterior of loaf is slightly browned and the interior reads 200-F on an instant read thermometer.