The problem with the recipe used by my Twitter friend is partly that it doesn't use a leaven to make sure that everyone is starting on the same page. Since you're using straight starter, you could be taking it at any point in the cycle. If the starter has recently been refreshed, it's only just getting going and probably isn't yet strong enough to properly ferment or raise your dough. If the starter is at the end of its cycle, the yeast is all worn out and it will also lack the oomph to make a good loaf of bread. Then again, if the starter is at peak bubbliness and you might have no problems at all! Very unpredictable.
This just means that you need to add in your own predictableness. Which is totally a word.
If you want to be totally correct and pro-baker-like about it, you can make your own leaven for this recipe by mixing a tablespoon of active, bubbly starter with 8 ounces of flour and 8 ounces of water and letting this stand for 10 to 12 hours until bubbly. You'll make a little more than 2 cups of starter with this, but just use what you need and add the remainder back into your starter.
But the more I mulled over this whole situation while crafting my 140-word response on Twitter, the more I realized that you really can use the starter to make a loaf of bread if you want to -- why not?! You just need to make sure you're using ripe starter. If you scoop out your two cups of starter roughly midway through the cycle, about 10 to 12 hours after you last refreshed it, then there's no reason why it won't work. It's all about getting active yeast into your bread, after all.
It was this idea of not making a leaven that stuck in my brain and kept niggling away at me. I've been baking sourdough bread for years now and am wholly indoctrinated into the Way of the Leaven. The idea of using straight starter felt somehow...wrong. And weird. And a little risqué. I had to try.
And, of course, it worked just fine. In fact, it was great. There were piles of toast and sandwiches galore in the week following my experiment. The bread was spongy and springy in all the right ways, and it had a nice yeasty flavor with a touch of sourdough tang. I also really liked the texture and the nutty-sweet flavor added by the oatmeal.
The biggest disadvantage that I can see is that using your starter like this either means being at its mercy whenever it reaches peak ripeness, or interrupting your regular refresh cycle so that you don't wind up starting your dough at, say, 9pm or whenever the starter would normally reach its peak. Personally, I just refreshed the starter before I went to bed and started the dough the next morning, about 12 hours later. I then refreshed my remaining starter again and was back in the saddle with my sourdough refresh cycle. I also usually keep a fairly small amount of starter (about a cup), so I added extra flour and water the night before I made the bread so I'd have enough for the recipe, and then I went back to my normal amounts afterward.
So satisfying to scratch that niggling itch. I made a few other tweaks to the recipe as I went, and I thought I'd share my adapted version below. Note that I use a starter with 50/50 mix of all-purpose flour and water by weight. Also, if you don't catch your starter at peak ripeness or you'd just like some extra insurance, add 1 1/2 teaspoons of active-dry or instant yeast to the dough. And if you love love love really sour sourdough, use starter that is at the end of its cycle, but be sure to add the extra yeast to ensure a good rise.
Oatmeal Sourdough Sandwich Bread
Adapted from Mother Earth News
Makes 2 sandwich loaves
2 cups sourdough starter, 10 to 12 hours since last refresh (or add 1 1/2 teaspoons active-dry yeast if using older starter)
1 1/4 cups milk, whole or 2%
3 tablespoons mild honey, like wildflower or clover
2 tablespoons olive oil
1 1/2 teaspoons salt
1 1/2 cups old-fashioned rolled oats
3 cups all-purpose flour
Stand mixer with a dough hook (I love my 10-year-old KitchenAid!), or you can mix the dough in a bowl and knead by hand
2 (1-pound) loaf pans
1. Mix the dough: Combine the starter, milk, honey, olive oil, and salt in the bowl of a stand mixer (or large mixing bowl), and stir until the starter and milk are combined. Stir in the oats, followed by the flour. Continue stirring until you form a rough, shaggy dough.
2. Knead the dough: Knead the dough using a stand mixer with a dough hook for 5 minutes, until the dough comes together into a smooth ball. Alternatively, knead against the counter for 8 to 10 minutes. If the dough sticks to the sides of the bowl or the counter while you knead, add more flour a tablespoon at a time until it stops; if the dough looks very dry and the flour isn't getting absorbed, add more milk a tablespoon at a time until the dough comes together. The finished dough should be quite sticky, but should easily form a ball and feel springy.
3. Let the dough rise for about 2 hours: Clean out the bowl, if needed, and then return the ball of dough to the bowl. (You can grease the bowl if you like, but I rarely do.) Cover the bowl and place it somewhere warm and out of the way to rise. Let the dough rise for about 2 hours -- it won't double in bulk, but it should look puffed and pillowy.
4. Divide and shape the loaves: Scrape the dough onto a lightly floured counter. Use a bench scraper to divide the dough into two even pieces. Shape into loaves by slightly flattening each piece of dough and then folding the top down and the bottom up, like a letter. Use the edge of your hand to gently press a crease down the length of the loaf and then fold it in half so that the surface of the loaf feels stretched and taut. Pinch the seam closed, then roll the loaf over so the seam is down. Grease 2 loaf pans and transfer the loaves to the pans.
5. Let the loaves rise for 1 to 1 1/2 hours: Cover the loaves and place them somewhere warm and out of the way. I usually place the pans in loosely-knotted plastic bags -- this keeps the loaves protected and prevents them from drying out while they rise, but since the bag puffs out around the pans, I don't worry that the dough will start sticking as it rises. Let the loaves rise until the domes have cleared the top of the pan. Depending on the temperature in your kitchen and the strength of your starter, this should take 1 to 1 1/2 hours or so.
6. Heat the oven to 450F: When you see the dome of the loaves just starting to peek over the top of the pan, but the loaves are not yet fully risen, start the oven preheating to 450F. This should give the oven a good 20 to 30 minutes to preheat before the loaves are ready. (If the loaves seem to be slow to rise, place them near oven while it heats so they can get an extra boost of warmth!)
7. Bake the loaves: Place the loaves in the oven. Bake for 20 minutes, then lower the oven temperature to 375F and bake for another 20 to 25 minutes. When finished, the loaves should be deeply browned on the surface with some of the bits of oatmeal starting to look burnt. (Don't worry -- the loaf won't taste burnt!) If you'd like to double-check that the loaf is done, poke it with an instant-read thermometer -- the finished loaves should register 190F internally.
8. Cool the loaves: Tip the loaves out of their pans and let them cool to room temperature on cooling racks before slicing. If you slice off a piece while the loaf is still warm, I promise not to tell.
9. Store the loaves: Loaves will keep for about a week loosely wrapped in a bread box or in plastic. To freeze, wrap the loaf (sliced or unsliced) tightly in aluminum foil, and then place in a plastic zip-top bag. Squeeze out as much air as possible and freeze for up to 3 months.