Making a 100% whole wheat sourdough sandwich bread has been on my baking bucket list for a long time. With cookbook recipe testing finished, the time was finally right! Although this loaf took many, many trials, I am pleased with how wholesomely delicious it turned out!

While I often replace about 30% of the flour in my go-to soft sourdough sandwich bread with whole grains, I knew making a completely whole wheat loaf would require some adjustments. One adjustment was amount of dough — because whole wheat does not rise as much as white flour, I had to increase the amount of dough in the tin to end up with slices that I considered tall enough.

Another adjustment was fermentation timetable. There is less “wiggle room” when it comes to whole wheat — the added nutrients cause fermentation to move quickly, which can cause the dough to overproof if you aren’t paying attention. Overproofing whole wheat doughs can lead to unpleasant sourness and a rougher crumb. For these reasons, I make this loaf all in one day (minus building the levain and soaker, which I prepare the night before). I experimented with refrigerating the dough partway through bulk fermentation (which I often do with other enriched doughs), but even with my fairly cold fridge the dough rose more than I expected and I ended up with overly sour loaves.

In addition to whole wheat flour, I decided to include an oatmeal soaker — I love the nutty tenderness oats add! Oats also hold on to moisture, helping this bread stay soft for days (though I especially enjoy this bread toasted)! I also used milk powder, maple syrup, and oil for additional softness and subtle sweetness. You can omit the milk powder if you want to keep this bread completely vegan, or try substituting a non-dairy milk powder. All in all, this loaf is nutty, wholesome, and just subtly sweet — — perfect for sandwiches and toast!

A few additional notes:

• If you’ve made any of the enriched sourdough loaves on this site, you may remember that two keys to a soft crumb and good rise are thorough mixing and full proofing. This is still the case with this loaf. However, it is easy to overknead whole wheat dough, especially using a stand mixer; go slowly and check the dough often for the windowpane. (Alternatively, you can knead this dough by hand.)
• If you follow me on Instagram, you may know that I worked quite a bit on trying to eliminate some small dense areas that can show up on the bottom and sides of pan loaves, particularly when using a 9x4x4 pullman loaf tin. After talking to some other bakers, a lot of reading, and additional tests, I’ve concluded that provided your fermentation is on point, this probably happens because the dough is being compressed as it rises and bakes. I don’t notice this issue in a standard 9×5 loaf tin (see comparison photos below), which has tapered sides (allowing the loaf to relax outwards). To me, this is an aesthetic issue — I don’t notice these areas when I eat the bread. Personally, I am willing to sacrifice a “perfect” crumb for a nice, tall slice; so I will continue to happily use my Pullman pan for this loaf! Keep in mind that there may be other reasons for dense spots — underfermentation or underbaking being the main ones.
• There are many different ways to shape a sandwich loaf; I describe one I like below. It is similar to how I shape my soft sourdough sandwich bread; but instead of dividing the dough into three pieces, I keep it in one piece — the dough seems to compress a little less this way.
• It’s important to bake and cool this loaf fully. Make sure the very center of the loaf registers 205F — there’s a lot of moisture in this loaf with the oat soaker, and if you underbake the insides will turn out gummy and the sides may cave in. Additionally, wait for the loaf to cool fully before slicing so the crumb can fully set — I like to give it at least 3 hours.
• As with all recipes but especially sourdough ones, the times listed below are for guidance/general ballpark. Exact timings will vary depending on the strength of your starter, how fresh your flour is, and the temperature of your environment. Paying attention to the physical cues — the appearance and feel of the dough and amount of rise — is much more important than sticking to a strict timetable!

100% Whole Wheat Sourdough Sandwich Bread with Maple and Oats

Makes one 9x4x4 or 9×5 loaf

Ingredients:

For the stiff sweet levain:

• 24g ripe 100% hydration sourdough starter
• 39g water, at room temperature
• 72g whole wheat flour
• 11g sugar (I used brown sugar)

For the oatmeal soaker:

• 60g rolled oats (regular, not quick)
• 150g boiling water 

For the final dough:

• 177g water, at room temperature 
• 34g neutral vegetable or olive oil
• 45g maple syrup 
• All of the stiff sweet levain
• 336g whole wheat flour (I used half organic hard whole wheat and half Flourist sifted red spring wheat)
• 30g milk powder
• 9g salt
• All of the oatmeal soaker

To finish:

• Additional rolled oats, for garnish (optional)
• 14g / 1 Tbsp melted butter (optional)

Method:

1. Make the stiff sweet levain (Day 1, evening): In a medium bowl, mix together the starter, water, whole wheat flour, and sugar until well combined. It should resemble a stiff dough. Cover and ferment at room temperature (74-76F) until tripled in volume and the top is starting to flatten, about 10-12 hours.
2. Make the oatmeal soaker (Day 1, evening): Place the oats in a small bowl and pour the boiling water over them. Stir to make sure all the oats are hydrated. Cover and let sit until you are ready to mix the dough. (I do this at the same time I mix the levain.)
3. Autolyse the dough (Day 2, morning): In the bowl of a stand mixer fitted with the dough hook, combine the water, oil, and maple syrup. Tear the ripe stiff levain into several pieces and add it to the liquid. Stir with a flexible spatula to disperse and break up the levain. Add the whole wheat flour and milk powder. Stir just until all the flour is hydrated and there are no dry spots. The dough should be fairly stiff at this point. Cover and let sit for 45 minutes.
4. Mix the dough: Add the salt to the autolysed dough. Mix on low (speed 1 on a KitchenAid) until the salt is evenly dispersed and the dough begins to smooth out, about 3-4 minutes. Increase the speed to medium low (speed 2-3 on a KitchenAid) and mix until the dough is very smooth and supple and reaches windowpane stage, about 5 minutes. Scrape down the dough hook a couple of times during this process to make sure the dough is evenly mixed. (Alternatively, you can knead by hand — it will take longer, but this dough is easy to handle.)
5. Add the oatmeal soaker: Add the oatmeal soaker and use your hands to squish it into the dough, folding the dough over onto itself several times to disperse the soaker evenly. Mix on low for one minute to make sure the dough is evenly mixed — do not overmix, or the gluten may start to break down. The dough may be a little sticky, but still strong and smooth and hold together easily. Transfer to a large oiled bowl or container for bulk fermentation. Desired dough temperature is 76-79F.
6. Bulk fermentation: Let the dough rise at room temperature until it has risen 60-75%, about 2-3 hours at 75-77F. Because the dough was well-developed during mixing, there’s no need to do any stretches and folds (though you can if you want to). When ready to shape, the dough should feel airy and puffy, but still strong — do not push the bulk too far as the high whole-grain percentage can cause the dough to overferment quickly.
7. Shape: Turn the dough onto a lightly floured surface. To create a very tight, even crumb (my preference for sandwich breads), use a rolling pin to roll the dough into a rectangle about 9 x 13. Starting with a short edge, roll the dough up tightly like a jelly roll. Let rest 10 minutes, uncovered. Roll into a rectangle again, along the seam, and re-roll like a jelly roll as tightly as possible. (Try to get the short edge as close to 9″ as possible, but a little under is fine — the dough will relax to fill the tin.)
8. Coat: Lightly grease a 9x4x4 or 9×5 loaf pan. If you want to coat your loaf with oats, lay down a clean, lint-free tea towel and sprinkle with a thin, even layer of rolled oats. Lightly spritz the shaped loaf with water, then carefully flip the loaf onto the towel, seam side up. Use your hands to rock the loaf back and forth a few times so that the oats stick to the loaf. Transfer the loaf to the prepared pan, seam side down. Cover with lightly oiled plastic.
9. Proof: Proof the loaf at room temperature until it has doubled in size and passes the “poke test” — when you gently poke the loaf with a floured finger, the indentation should fill back very slowly. In a 9x4x4 pan, the dough should have risen about 1 inch above the rim in the center (in a standard 9×5 pan, about 2 1/2 inches). This typically takes me about 1 1/2 to 2 1/2 hours; but exact timing will depend on the warmth of your kitchen and strength of your starter.
10. Preheat the oven: About 45 minutes before you anticipate your loaf being ready to bake, preheat your oven to 425F with a rack in the middle and a rack below (for steaming, optional). About 10-20 minutes before baking, place a few small dishtowels (preferably ratty ones) in a roasting pan. Pour enough very hot or boiling water over the towels to fully saturate them. Place the roasting pan in the oven on the lower rack. (This is optional but helps create steam in the oven. I find this gives the loaf a better rise and shiny crust without needing to use an egg wash.)
11. Bake and cool: Bake the loaf for 20 minutes, then remove the roasting pan. Turn the oven temperature down to 400F and continue baking for another 20-25 minutes, or until the top is well browned and the internal temperature of the very center of the loaf reaches 205F. (If the loaf is taking on too much color for your liking, tent it with foil midway through baking.) Once the center has reached 205F, remove loaf from the tin and return to the oven to bake for 1-2 more minutes (optional, for more color on the sides/bottom). Transfer the loaf to a wire rack and brush melted butter over the top and sides — this optional finish helps keep the crust soft and flavorful. Let the loaf cool completely before cutting, at least 3 hours. Store leftovers in a sealed plastic bag for 4 to 5 days, or freeze for longer storage.