Oats—Good for You, and Sourdough Bread Too

ately, I have been wondering if oats, or better-said flour made from oats, would be a good solo grain for sourdough bread. Sadly, this grain lacks the gluten needed to make bread hold together but are one of the healthiest grains cultivated. Even more, the nutty flavor makes me want to explore it as a solo bread grain in sourdough bread making. 

I know that is is often added to bread. For example, we featured Cynthia’s Sourdough Oatmeal Wheat Bread last April and nearly every online Oatmeal Sourdough bread recipe calls for wheat flour mixed with oat flour. However, since it has no gluten, which is essential for the visco-elastic properties of wheat flour needed in bread making, the challenge then is to get a decent loaf with just fermentation.

But first, let’s learn a bit more about this important grain.

Part I: Short History of Oats

“Oates, although they are of all manner of grain the cheapest because of their generality, bring a grain of that goodness and hardness that it will grow in any soil whatsoever, be it never so rich or never so poor, as if nature had made it the only loving companion and true friend to mankind, yet is it a grain of that singularity for the multiplicity of virtues, and necessary uses for the sustenance and support of the family, that not any other grain is to be compared with it; for if any other have equal virtue, yet it hath not equal value, Then it wants many degrees of equal virtue so that joining virtue and value no husband housewife or housekeeper whatsoever health so true and worthy a friend as his aunts are.”—Gervase Markham (1676) in his“Of the Excellency of Oats, and the Many Singular Virtues and Uses of Them in a Family”.^[2] 

Avena sativa or the common oat, is a variety of cereal grain mostly grown for livestock as feed. But many people humans eat it too. In fact, there is archaeological evidence of human consumption of wild oats long before cultivation began in areas around the Fertile Crescent in 2000 BC.

This grain, much like the other ancient grains already considered in other blog posts, moved from its wild state to a cultivar as people began to farm and congregate in cities in Egypt and the Jordan Valley.^[1]

“The wild origin of cultivated oats is still debated, but recent studies of cultivated oats’ genome strongly suggests that all cultivated oat species come from the wild oat species Avena sterilis. The domestication of Avena sterilis is believed to have occurred in two distinct locations – in the Fertile Crescent and along the North African coast/Southern coast of the Iberian Peninsula. Due to slight differences in their genome, oats originating from the fertile crescent are known as common oats, while those domesticated in Iberia are known as byzantina oats.^[1]—Whole Grains 101 

Oats initially arrived in both the Middle-East and Europe as a weed and only later was selected as a secondary crop by farmers.^[3]

“Farming and trading flourished in Europe by 2000 BC. Wheat and barley seed were traded bringing oat and rye with them as weed contaminants. Although the historical record is limited, cultivated oats were identified in northern regions of Western Europe between 4500-400 BC where climatic conditions were wet and cold. Oats were favored in these conditions compared to wheat and barley… [and] were ranked fourth in importance after wheat, barley and rye by the Renaissance.

“Oats could flourish in areas where wheat and barley produced marginal yields. Although the primary use of oats was for animal feed, by 1500 it was the principal grain crop for human consumption in Scotland, Wales, Ireland and Britain.^[4]—Pamela Zwer, in Cereal Grains (Second Edition)

Because this grain grows so well in the regions of Northwest Europe, it quickly joined the trifecta of rye, wheat, and barley, which also grow well there. Initially, as fodder for their animals, many families soon found it good in their family diet right along with the livestock.

Cultivation of Oats

In modern times, oats are planted and harvested increasingly less often. Still, in 2018, world-wide production was 23 million metric tons, (down 11% from 2017). Russia leads in world production with 20% of the total, with Canada second at 15%. “Other major producers include Australia,  Spain, Poland, and China, each with more than one million metric tons.^[4]

There are 26 know species of the genus Avena, four of which “are cultivated ones (Avena sativa, Avena byzantina, Avena strigosa, and Avena abyssinica). The common oat (sativa) is the main cultivated species”^[5] and is the oat we find on the shelves in grocery stores.

Oats are an annual plant, which means they can be planted in the Fall for a later summer harvest or in the Spring for an early fall crop. Because of their lower summer heat requirements and bigger rain tolerance than other cereal grains, like barley, rye, or wheat, oats are especially important in regions with cool, wet summers, like Northwest Europe and even as far north as Iceland. 

Part II:  Dietary Benefits of Oats

The carbs in oats are mostly starches and fiber. Oats pack more protein and fat than most other grains and are a good source of beta glucan, a unique, soluble fiber linked to multiple health benefits.

Popular in Scotland, oatcakes  are similar to crackers or biscuits, baked in the oven on a griddle

USDA FoodCentral Data for 100g (1 heaping cup) raw oats.^[9]

 

 

 

 

 

 

Most often served as oatmeal or oat milk, oats are also used in baked goods, like cookies or oatcakes. But much less often as oat bread, and even less often milled as whole oat flour.

Oats are packed with minerals and vitamins, such as B vitamins, copper, iron, manganese, magnesium, phosphorus, selenium, and zinc.

They also come with their own unique plant compounds. Oats are the only dietary source of avenathramides, a powerful antioxidant that helps regulate blood pressure and reduce arterial inflammation.

Like other cereal grains, oats contain polyphenol antioxidants. Whole oats and oat brain have phytic acid, which blocks the absorption of iron and zinc but can be mitigated through sourdough fermentation.

The soluble fiber in this grain, beta-glucans are most commonly used to help prevent and fight heart disease^[6] and high cholesterol.^[7]

Oats are low in sugar, with only one-percent coming from sucrose, making them exceptional in lowering insulin responses.^[8]

Carbs

By dry weight, carbohydrates make up 66% of oats. About eleven-percent of that is fiber and eighty-five-percent is starch.

“The starch in oats is quite unlike the starch in other grains. It has a higher fat content and a higher viscosity, which is its ability to bind with water. “

“Three types of starches are found in oats:

1. Rapidly digested starch (7%). This type is quickly broken down and absorbed as glucose.
2. Slowly digested starch (22%). This form is broken down and absorbed more slowly.
3. Resistant starch (25%). Resistant starch functions like fiber, escaping digestion and improving gut health by feeding your friendly gut bacteria.^[10] —Oats 101: Nutrition Facts and Health Benefits

Fiber

As mentioned above, most of the fiber (beta-glucans) in oats is soluble. This fiber forms a gel-like solution that is great at slowing digestion and leaving dieters more satisfied, longer. This also seems to lower blood sugar and insulin levels after a meal higher in carbohydrates. And it has been shown “to lower cholesterol, especially LDL (bad) cholesterol, and may thus decrease your risk of heart disease.”^[11]

Protein

By dry weight, oats are 11-17% protein, which is higher than other grains. This makes them an excellent plant source of protein. Most of this protein (80%) is avenin, which is not found in other grains but may lead to a digestive track problem similar to gluten-sensitivity in some people.^[12] However, Healthline promises, “pure oats are considered safe for most people with gluten intolerance.”^[13] and “clinical studies have proved that consumption of moderate or even large amounts of oat can be tolerated by the majority of adult celiac disease patients.”^[14] 

Part III:

Making an Oat Flour Sourdough Starter

With all that information,  I began some additional research to see if anyone has succeeded in making a 100% oat starter.

Right away I stumbled on this post “Oat Sourdough – The gluten-free sourdough experiment,” by Gethin Sherrington. He claims to be “the fourth-best physics trained baker-chef in all of North West Wales.” I am not sure what that means, but it brought a big smile to my face.

In his experiments, Geth shared some real science on the matter.

His paper began with this abstract stating that over a four day period he was able to convert “a 50% hydration wheat-based sourdough starter [that] was refreshed with oats and water…[into] a stable sourdough culture in an oat-based medium.”^[15] Though this culture was started with a wheat sourdough start, his method (see table below) produced a start with gluten levels “below the legal threshold of 20 ppm, which meant that the oat starter could then be considered gluten-free.”^[16]

“With Coeliacs, gluten intolerance, and the trend in gluten-free food all on the rise,” he wrote, “there is certainly a demand for gluten-free. It’s, therefore, a shame, given the corresponding popularity of fermented foods, that a gluten-free [oat] sourdough is not possible.”

And with that, he began his experiment to convert a wheat-based starter “to being entirely oat-based and gluten-free… The question [he] answered though, is whether an alternative starch, such as oats, could serve as a gluten-free, alternative fuel source, for a sourdough starter.”³

Using the table above, and following Geth’s instructions, I had an active oat started in just four days. And knowing that you can make an oat-based, the gluten-free starter is intriguing.

Part IV:

Making 100% Oat Flour Sourdough Bread

At Abigail’s Oven, we have explored several ancient grains for sourdough, with some success. But with each grain used there was a noticeable decrease in gluten forcing us to add bread flour or Abigails Premium White Whole Wheat.

Oats do not generally contain any gluten unless they have been contaminated at the mill, which makes me wonder about oats as a sourdough bread grain. Geth used his oat starter in a test recipe he called Honey and Oat Sourdough, but it was made with only 25% oat flour, 25% whole wheat flour, and 50% bread flour. He also added instant yeast, so he probably did not get a long enough ferment to make the dough digestible enough for those with gluten sensitivities.

As I searched a bit more I came across a recipe at Cookpad.

Felice from Matsumoto, Japan, made a pretty good stab at it, but still added two grams active dry yeast. So I set out to adapt what she did, but with all oat flour.

My 100% Oat Flour Sourdough

1. To begin you will need to build an oat sourdough starter by adding one scant tablespoon (20g) of wheat sourdough starter to ¾ cup (180 g) purified water. Stir to dissolve, then stir in 1 cup (90g) of oat flour, (to make oat, flour process 1½ cups of oatmeal in your food processor or blender until it is the consistency of flour, then measure out one cup). Set this aside for 24 hours at room temperature.
   The next day, discard all but one scant tablespoon (20g) of the oat starter. Add ¾ cup (180 g) purified water, stir to dissolve, then stir in 1 cup (90g) of oat flour, add set aside for another 24 hours. Repeat this for each of the next two days.
2. Mix the preferment ingredients in a bowl. Cover and allow to ferment for 12-16 hours at room temperature.
3. Mix the oat soaker ingredients in a separate bowl. Cover, put in the refrigerator and let soak for at least 4 hours up to 12 hours.
4. On baking day, in a larger bowl, mix the oat flour preferment, oat soaker, with the additional water and quick oats. This mixture will be too moist to knead. Just bring it together with a spatula or your bread mixer and mix for 5 minutes.
5. Grease your loaf pans and dust the sides with some rolled oats. If using two smaller loaf pans, divide the dough into half.
   If using one large pan, put it all in that one.
6. Sprinkle a few oats over top if you like. Cover and let rise for about 1 hour.
7. Preheat oven to 480°F [250°C] and prepare a steam pan at the bottom of the oven. Pour some boiling water into this pan when you put the bread in the oven.
8. Bake for 10 minutes at 480°F [250°C] then remove the steam pan. Lower the temperature to 400°F [ 200°C], then bake for another 25-35 minutes for smaller loaves or  65-70 minutes for bigger pans. (Check the internal temperature to make sure they are 200°F [93 °C] before removing)
9. Remove from the baking pans to cool on a rack. Serve toasted with butter and jam! 

The texture of this bread was not good. It fell apart after slicing, not even making it whole to the toaster. But if you are gluten intolerant it may be worth baking it and letting it sit a day or two in plastic to firm up.

For the rest of us, I suggest going back to some whole wheat or vital gluten and oat flour combinations to get a more traditional crumb and slice. With a long ferment, most wheat gluten will be mitigated anyway.

Oats of course are not the only gluten-free grain that can support a sourdough culture, but they are one of the most accessible. In the past, I have worked with ancient grains and long ferments to minimize gluten in bread, but Celiacs still cannot tolerate those breads.

I wrote about some my own experiments with other grains last December when our daughter-in-law, who suffers from Celiac disease came to visit over the holidays. I love the challenge to bake for her when she comes to town.

Endnotes

^1- Whole Grains 101, Grain of the Month Calendar, “Oats—January Grain of the Month,” Whole Grains Council
^2- Michael R.Best, editor. The English Housewife, by Gervase Markham, McGill-Queen’s University Press, 1986, pp. 199–203
^3- Zhou, X.; Jellen, E.N.; Murphy, J.P.; “Progenitor germplasm of domesticated hexaploid oat“. Crop Science. 39 (4): 1208–1214
4- Pamela Zwer, “Oats: Grain-Quality Characteristics and Management of Quality Requirements,” Cereal Grains (Second Edition), Assessing and Managing Quality, Woodhead Publishing Series in Food Science, Technology and Nutrition, 2017, pp. 235-256
^5- “Oats production in 2018, Crops/World Regions/Production Quantity from pick lists”. Food and Agriculture Organization, Statistics Division, FAOSTAT. 2019. Retrieved 14 August 2020.
^6- Aarsaether, E., Rydningen, M., Einar, Engstad R., and Busund, R. Cardioprotective effect of pretreatment with beta-glucan in coronary artery bypass grafting. Scand Cardiovasc.J 2006;40 pp. 298-304
^7- M. Boczkowska, W Podyma, B.Łapiński, in Genetic and Genomic Resources for Grain Cereals Improvement, 2016, pp. 159-225
^8-Alminger, M. and Eklund-Jonsson, C. Whole-grain cereal products based on a high-fiber barley or oat genotype lower post-prandial glucose and insulin responses in healthy humans. Eur.J.Nutr. 2008;47(6):294-300.
^9- Raw Oats, USDA FoodCentral Data
^10- Oats 101: Nutrition Facts and Health Benefits, Healthline

• W.Berski, A.Ptaszek, P.Ptaszek, R.Ziobro, G.Kowalski, M.Grzesik, and B.Achremowicz, Carbohydrate Polymers, Volume 83, Issue 2, 10 January 2011, Pages 665-671;
• R.Hoover and S.P.J.N.Senanayake, “Composition and physicochemical properties of oat starches,” Food Research International, Volume 29, Issue 1, January 1996, Pages 15-26;
• R Hoover, C Smith, Y Zhou, and R.M.W.S Ratnayake, “Physicochemical properties of Canadian oat starches,” Carbohydrate Polymers, Volume 52, Issue 3, May 2003, Pages 253-261

^11- Healthline, ibid.
^12- Allergies and Intolerance to Grains—Gluten in Grains, Australian Grain and Legumes Nutrition Council
^13- Rasane P, Jha A, Sabikhi L, Kumar A, Unnikrishnan VS. Nutritional advantages of oats and opportunities for its processing as value-added foods – a review. J Food Sci Technol. 2015;52(2):662-675.
^14- Australian Grain and Legumes Nutrition Council, ibid.
^15- Gethin Sherrington, “Oat Sourdough – The gluten-free sourdough experiment“, March 2018, Artisaniaeth.com
^16- Codex Alimentarius Standard (2015) Codex Standard for Foods for Special Dietary Use for Persons Intolerant to Gluten.
^17- Sherrington, ibid.

In the comment section below we would love to hear about your experience about eating oat sourdough bread.

Author: Darryl Alder, blogs for Abigail’s Oven, The Voice of Scouting, The Boy Scout, EternalCore.org, and SearchIsaiah.org. His hobbies include gardening vegetables; planting annuals and perennials; baking artisan sourdough bread; outdoor cooking, and Scouting. You can follow him on Facebook, Instagram, and Twitter.