An In-Depth Guide to Flour Types for Sourdough Baking: Spotlight on Ancient Grains

Sourdough bread's complex flavors and textures largely owe their existence to the flour that's used. For those looking to expand their sourdough repertoire and delve into ancient grains, understanding the wide array of flours available is crucial. This guide aims to provide an in-depth look into the world of flours, both common and ancient, and how they influence sourdough baking.

Understanding Traditional and Ancient Grain Flours

1. All-Purpose Flour

Often seen as the jack-of-all-trades in the baking world, all-purpose flour is a mix of hard and soft wheat with a moderate protein content around 10-12%. This versatile flour yields a light and tender crumb in sourdough, making it an excellent choice for beginners.

• Understanding All-Purpose Flour: All-purpose flour is a blend of high-gluten hard wheat and low-gluten soft wheat. It's a jack-of-all-trades flour that is designed to be used in a wide variety of baked goods. However, its protein content, and thus gluten potential, is generally lower than bread flour. This means the dough will be less elastic and have a softer, tighter crumb structure. When working with all-purpose flour, it's crucial to understand that your sourdough may not rise as high or have the same open crumb as a loaf made with bread flour.

• Managing Hydration: All-purpose flour typically absorbs less water than bread flour or whole wheat flour. As a result, you might find that you need to reduce the hydration level of your dough when using all-purpose flour. Be prepared to adjust the amount of water in your recipe to achieve the right dough consistency.

• Optimizing Fermentation: All-purpose flour can ferment just as well as other flours, but due to its lower protein content, the structure of your dough might be weaker. To compensate, you can incorporate more stretch and fold cycles during bulk fermentation. This will help to strengthen the gluten network and add more structure to your dough.

• Fueling Your Sourdough: All-purpose flour has all the necessary nutrients to fuel your sourdough starter. However, keep in mind that because of the lower protein content, your starter might not be as vigorous or active as when fed with higher protein flours. Regular feeding and maintenance are key to keeping your sourdough starter healthy.

• Encouraging Gluten Development: While all-purpose flour has a lower protein content than bread flour, it still has enough to create a satisfactory gluten network. Kneading the dough sufficiently and giving it ample time to rest during the autolyse and bulk fermentation stages will help promote gluten development.

All-purpose flour can be a great choice for sourdough baking, especially for those who prefer a softer crumb or who are just getting started with sourdough. While it may require some adjustments compared to using bread flour or whole wheat flour, understanding its unique characteristics can help you bake delicious loaves.

2. Bread Flour

With a higher protein content (12-14%), bread flour is tailored for yeast bread baking, including sourdough. The increased gluten development gives sourdough bread a chewy texture and better shape retention. I typically use this the most. It offers a great "oven-spring" because of the high protein content.

• Understanding Bread Flour: Bread flour is milled from hard wheat varieties and has a higher protein content compared to all-purpose flour, typically around 12-14%. This higher protein content translates into more potential gluten, providing more elasticity and strength to your dough. When working with bread flour, expect your sourdough to rise higher and exhibit a more open crumb compared to dough made with all-purpose flour.

• Managing Hydration: Bread flour can absorb more water than all-purpose flour due to its higher protein content. This may necessitate an increase in the hydration level of your dough when using bread flour. Begin with a moderate increase in the water content and adjust as needed to achieve your desired dough consistency.

• Optimizing Fermentation: The higher protein content in bread flour can support a strong, elastic dough structure, capable of trapping the gas produced during fermentation effectively. This can lead to an excellent rise in your sourdough. However, be mindful of over-fermentation, as it can lead to overproofed dough which may collapse during baking.

• Fueling Your Sourdough: Bread flour provides a robust food source for your sourdough starter due to its high protein content. This can lead to a very active and vigorous sourdough starter. Regular feeding and maintenance remain important to keep your starter healthy and balanced.

• Encouraging Gluten Development: With its high protein content, bread flour is a great candidate for developing strong gluten networks. Kneading your dough adequately and incorporating a good autolyse stage will help to ensure optimum gluten development. Also, consider the stretch and fold technique during bulk fermentation to align the gluten strands and strengthen the dough.

Bread flour, with its high protein content, is a popular choice for sourdough baking, yielding loaves with good rise and an open crumb structure. Understanding its unique characteristics can help you manipulate the flour's properties to your advantage and bake an impressive sourdough loaf.

3. Whole Wheat Flour

Milled from the entire wheat kernel, whole wheat flour is nutrient-rich and gives sourdough a denser texture and a hearty, nutty flavor. Its protein content is approximately 14%, but gluten formation may be less effective due to the presence of bran and germ.

• Understanding Whole Wheat: Whole wheat flour is made from the entire wheat kernel — the bran, germ, and endosperm. The increased bran content gives whole wheat its high fiber, vitamin, and mineral content. However, this bran content can also interfere with gluten development because the sharp edges of bran can cut through the gluten strands, leading to less elasticity and more propensity for tearing in your dough. Therefore, when using whole wheat flour, treat the dough gently during the kneading and shaping processes to prevent damage to the developing gluten network.

• Managing Hydration: Whole wheat flour tends to absorb more water than white flour, due to its higher fiber content. This necessitates an increase in the hydration level of your dough when using whole wheat flour. Begin by increasing the water volume by 5-10%, and adjust as needed. Hydrating the dough appropriately will lead to a softer and more workable dough.

• Optimizing Fermentation: Whole wheat flour requires a longer fermentation period compared to white flour due to slower enzyme activity. However, the longer fermentation period can yield more complex flavors in your finished loaf. Consider extending the bulk fermentation period and maintain a cooler environment to achieve a slow, steady rise.

• Fueling Your Sourdough: The nutrients in whole wheat flour can fuel more vigorous fermentation activity in your sourdough starter. Monitor your dough closely, especially if you're used to working with white flour, as whole wheat sourdough may rise more quickly or become more acidic.

• Encouraging Gluten Development: Despite its high protein content, the presence of bran and germ in whole wheat flour can impede gluten network formation. A longer autolyse period, more frequent stretch and folds, and higher hydration can help to promote better gluten development when using whole wheat. Remember to be patient and gentle with the dough during these processes to help the gluten network form and strengthen.

Working with whole wheat flour in sourdough baking can be a rewarding endeavor, leading to hearty and flavor-rich loaves. While the process may require some adjustments, understanding these key factors will help you navigate the nuances of whole wheat sourdough baking.

4. Rye Flour

Rye flour lends a distinctive flavor to sourdough and results in a denser, moister crumb. Its gluten-forming proteins are lower, making dough handling slightly more challenging but rewarding in terms of flavor.

• Understanding Rye Flour: Rye is a type of grain that's different from wheat. It has a lower gluten content and a higher percentage of soluble fiber, which makes rye dough sticky and dense. The gluten that does form is not as strong or elastic as wheat gluten. As a result, rye bread tends to be denser, with a tighter crumb. When baking with rye, anticipate a different dough behavior compared to wheat-based doughs.

• Managing Hydration: Due to the high absorption rate of rye flour, it often requires more water than wheat flours. The precise hydration level depends on the percentage of rye flour used in your recipe and the type of rye flour (dark rye, light rye, etc.). The dough might seem stickier than what you're used to with wheat doughs, but resist the urge to add too much extra flour, as this can result in a dry and dense loaf.

• Optimizing Fermentation: Rye flour ferments faster than wheat flour because it contains a high amount of amylase enzymes that break down starches into sugars. This means your sourdough might rise and ferment more quickly. Pay close attention to the fermentation process to avoid over-proofing your dough.

• Fueling Your Sourdough: Rye flour is packed with nutrients, making it a great food source for your sourdough starter. In fact, many bakers find that maintaining a rye sourdough starter results in a more active and vigorous culture.

• Encouraging Gluten Development: While rye does contain some gluten, it's not as strong or elastic as the gluten found in wheat. That's why 100% rye breads tend to be denser and have a tighter crumb. If you want a lighter texture with the flavor of rye, consider using a blend of rye and wheat flours. When kneading rye dough, know that the process won't develop the gluten as it does in wheat dough, so it may not become as smooth or elastic.

Rye flour brings a distinct flavor and character to sourdough. While it behaves quite differently from wheat flours, understanding these unique characteristics can help you navigate the challenges and bake a wonderfully flavorful rye sourdough loaf.

5. Spelt Flour

An ancient grain, spelt flour brings a mildly sweet and nutty flavor to your sourdough. It has a higher protein content than all-purpose flour but forms a more fragile gluten network. Spelt can absorb more water, so you may need to adjust hydration levels in your recipes.

• Understanding Spelt Flour: Spelt is an ancient grain that's a relative of modern wheat. It has a higher protein content than common wheat, but the gluten in spelt is more fragile. This means that while your spelt dough will be quite extensible, it won't be as elastic or hold its shape as well as dough made with common wheat flour. When baking with spelt, expect a slightly different texture and a more delicate handling process compared to wheat-based doughs.

• Managing Hydration: Spelt flour is more water-absorbent than common wheat flour, meaning it often requires higher hydration in your dough. Be prepared to add a bit more water than you might with a similar wheat flour recipe. However, because of the fragility of spelt's gluten, it's important not to make your dough too wet, as it can cause the dough to spread more easily.

• Optimizing Fermentation: Spelt flour ferments more quickly than common wheat flour due to its higher enzymatic activity. This means that your sourdough might rise more quickly, and you'll need to keep a close eye on your dough during the fermentation process to prevent over-proofing.

• Fueling Your Sourdough: Spelt flour is a nutrient-rich food source for your sourdough starter. You may find that your starter is quite active when fed with spelt flour, but also remember that over-fermentation can occur more quickly due to spelt's rapid fermentation time.

• Encouraging Gluten Development: While spelt does contain gluten, it's not as strong as the gluten found in common wheat. This is why spelt dough requires gentle handling to prevent breaking the fragile gluten strands. Kneading should be minimal and gentle, and the stretch and fold technique can be especially effective.

Spelt flour can be a wonderful addition to your sourdough baking. Despite it needing a bit more care in handling and watching closely during fermentation, its unique nutty flavor and soft texture make it a worthwhile exploration in your sourdough journey.

6. Kamut (Khorasan Wheat) Flour

Kamut, also known as Khorasan wheat, is an ancient grain with unique attributes that can bring depth and richness to your sourdough. Kamut flour is known for its sweet, buttery flavor and high protein content. Its gluten is more easily digestible compared to modern wheat, but it may require extra kneading to develop fully.

1. Understanding Kamut Flour: Kamut is a variety of ancient wheat known for its rich, nutty flavor and golden color. It has a higher protein content than common wheat, which can contribute to a stronger gluten network. However, the gluten structure is less elastic, which means Kamut dough might not hold its shape as well as a dough made from common wheat.

2. Managing Hydration: Kamut flour is quite absorbent, often requiring a higher hydration level compared to common wheat flour. You may need to adjust the amount of water in your recipe to achieve the desired dough consistency. However, due to the lower elasticity of Kamut's gluten, be careful not to make your dough too wet to avoid excessive spreading.

3. Optimizing Fermentation: Kamut flour can ferment at a similar rate to common wheat flour. However, the higher protein content can lend itself to a strong rise in your sourdough. Be mindful of your dough during the fermentation process to prevent over-proofing, which can lead to a dough that collapses during baking.

4. Fueling Your Sourdough: Kamut flour provides a robust food source for your sourdough starter due to its high protein content. This can lead to a very active and vigorous sourdough starter. Regular feeding and maintenance remain crucial to keep your starter healthy.

5. Encouraging Gluten Development: With its high protein content, Kamut flour offers great potential for developing a strong gluten network. However, the gluten is less elastic than that of common wheat. A gentle kneading process and sufficient rest during the autolyse and bulk fermentation stages will promote gluten development and strengthen the dough.

Baking with Kamut flour can yield wonderfully flavorful sourdough with a distinctive color and nutty taste. While handling Kamut dough may require some adjustments compared to common wheat, understanding its characteristics can help you bake a uniquely delicious loaf.

7. Einkorn Flour

Einkorn is a fascinating ancient grain with characteristics that set it apart from other wheat varieties. As one of the earliest domesticated wheat varieties, einkorn flour adds a rich, nutty flavor to sourdough. However, it has a weak gluten structure, so it's best used in combination with other flour.

1. Understanding Einkorn Flour: Einkorn is one of the earliest forms of wheat, known for its rich, nutty flavor. It has a lower gluten content compared to common wheat, making Einkorn breads denser with a tighter crumb. Additionally, the gluten that does form is weaker, so Einkorn dough is more delicate and less elastic. Anticipate a different dough handling and texture when baking with Einkorn.

2. Managing Hydration: Einkorn flour can absorb less water compared to other wheat flours, so you may need to reduce the hydration level of your dough. This can be a trial-and-error process, so start with less water and adjust gradually until you achieve your desired dough consistency.

3. Optimizing Fermentation: Einkorn ferments at a slower pace than common wheat flour, partly due to its lower gluten content. This means your sourdough might take longer to rise. Patience is key here—giving your dough ample time to ferment will result in a more flavorful loaf.

4. Fueling Your Sourdough: Einkorn flour is packed with nutrients, making it a great food source for your sourdough starter. However, you might find that your starter ferments more slowly when fed with Einkorn due to the flour's lower gluten content.

5. Encouraging Gluten Development: Einkorn has lower gluten content and its gluten is weaker than that in common wheat. Kneading should be done gently to avoid overworking the fragile gluten structure. The stretch and fold method can be effective during bulk fermentation for aligning the gluten strands and building dough strength.

Baking with Einkorn flour presents a unique opportunity to experiment with an ancient grain that offers a distinctive flavor and nutrient profile. Although Einkorn behaves differently than common wheat flours, understanding these nuances can guide you to achieve a delicious, well-crafted sourdough loaf.

8. Emmer (Farro) Flour

Emmer, also known as farro, imparts a sweet, earthy flavor to sourdough. Emmer, another ancient grain variety, has a distinct flavor profile and set of characteristics that can bring a unique quality to your sourdough. It contains a moderate amount of protein and can be used in a similar way to spelt, albeit with a slightly lower hydration level. Here's a guide to effectively using Emmer flour in your sourdough baking:

1. Understanding Emmer Flour: Emmer, sometimes referred to as farro, is an ancient wheat variety that's known for its deep, earthy flavor. It has a moderate protein content, and like other ancient grains, the gluten in emmer is different from that in modern wheat. Emmer's gluten is weaker, which means that while the dough will have some extensibility, it won't be as elastic or hold its shape as well as dough made with modern wheat flour.

2. Managing Hydration: Emmer flour is somewhat absorbent, and you may need to increase the hydration level in your dough compared to common wheat flour. However, due to the weaker gluten, it's important not to make the dough too wet, as it could lead to a loaf that spreads out during baking.

3. Optimizing Fermentation: Emmer flour can ferment more slowly than modern wheat flour due to its unique composition. This means that your sourdough may require more time to rise. Be patient and allow ample time for fermentation to achieve the desired rise and flavor in your loaf.

4. Fueling Your Sourdough: Emmer flour is nutritionally dense, making it a good food source for your sourdough starter. However, remember that due to the slower fermentation rate, your starter might require longer fermentation periods when fed with emmer flour.

5. Encouraging Gluten Development: While emmer does contain gluten, it is not as strong or elastic as the gluten found in modern wheat. Gentle kneading can help align the gluten strands, and the stretch and fold method can be especially useful during bulk fermentation to help strengthen the dough.

Emmer flour can bring a unique, rich flavor and texture to your sourdough. While it requires a slightly different approach than modern wheat, understanding its characteristics can lead to exciting new variations in your sourdough creations.

Converting Between Flours in Sourdough Baking

Transitioning between different flours can be tricky due to their unique properties. Here are some general guidelines:

1. All-Purpose to Bread Flour: Substitute with an equal amount, but anticipate a chewier texture in your bread due to higher protein.

2. All-Purpose to Whole Wheat/Spelt/Emmer/Kamut: Start by substituting half of the all-purpose flour with the ancient grain flour. These flours absorb more water, so you may need to increase hydration slightly.

3. All-Purpose to Rye/Einkorn: These flours have weaker gluten structure. Start by replacing just 20-25% of the all-purpose flour and adjust based on your preference.

Remember, each type of flour brings unique characteristics to your sourdough, and substitutions may require further adjustments in your recipe.

Exploring different types of flour, particularly ancient grain flours, can vastly broaden the flavor and texture profiles of your sourdough bread. This guide serves as a stepping stone in your exploration of the vast world of flours. Happy baking!