A year or so after starting our research for Modernist Bread, we thought we knew a fair amount about rye. Much of it was based around one central theme: rye bread is dense and brick-like. It took a cross-cultural mix-up to help us see rye flour, and rye bread, for all its nuance. And what a revelation it was! It proved to be one of the most eye-opening discoveries we made in the course of developing Modernist Bread.
Here, in the United States, it has long seemed like there is no such thing as a 100% rye that’s as fluffy as a wheat bread but made without wheat flour or gluten. But in rye-loving countries such as Austria, you’ll find those breads everywhere. We call these “high-ryes,” and we’ve wondered why these breads are so elusive outside Austria, Germany, and Scandinavia.
While working on the book, we brought two renowned bakers from Austria, both famous for their rye bread, to our lab in a sort of international baking exchange. We set them up with the ingredients, but when they tried to work our American rye flour into a proper dough for their signature bread, they struggled with it. Something was clearly wrong. But what?
It turns out it was the rye flour. We learned that rye flour can be profoundly different depending on where you buy it. We use the flour that’s available to us—that is, American-made rye flour. They use the flour that’s available to them, which is milled in Austria. They had come here assuming that our rye flour would be essentially the same as theirs, so they didn’t bring their own. It turns out they were wrong.
We also had assumed that all rye flours around the world share similar characteristics—and that those characteristics make it difficult, if not impossible, to make an open-crumb bread. All we knew was that rye flour made brick-like breads. It turns out that we were wrong too.
Finding Better Rye Flour
When we managed to get a 30 kg / 66 lb sack of Austrian flour and used it in our recipes, the result was extraordinary. Whereas our American-made rye flour makes a blobby, cement-like dough, Austrian flour mixes into something that can be stretched, almost as if there was gluten in it (which, functionally, there isn’t. Learn more about the science behind rye in bread). Once baked, the Austrian rye bread had a nice crown and an open crumb structure with some of the chew and springiness that’s associated with gluten. It also had a depth of flavor, with notes of licorice and molasses, while many American-made ryes taste more like wet grass.
The Keys: Grain and Particle Size
What made this flour so different? We consulted baking experts, cereal chemists, and millers, but no one could explain it. Finally, we found the answer in a paper written by German cereal scientists. The paper actually helped us understand two things: first, rye grown for the Austrian market is different from that grown in the United States; second, particle size matters.
In Austria and other countries where rye is a staple of the diet, considerable research goes into improving the rye grain to make better rye bread. In the United States, most rye is grown as a cover crop, so varieties are chosen with that in mind, not the grain’s baking characteristics. When it’s time for harvest, more rye is used for animal feed than for human food. That’s how we in the United States have wound up with subpar ryes.
In Austria, rye flours are tested and classed by their Amylograph numbers, which predict baking behavior by evaluating enzyme activity and starch gelatinization. Millers in the United States do extensive testing on wheat flour, but when we asked them about tests for rye flour, most of the millers said, essentially, “Why test? It’s rye.”
The other key difference between Austrian and US rye flour is the way it’s milled. The Austrian flour is often milled finely, down to a very small particle size, with almost all the bran and germ sifted out. It’s much finer than American bread flour. American rye flour, by contrast, isn’t ground so finely. It’s often marketed as a coarsely ground “meal.” In addition, most US rye flour also contains bran and germ, making it analogous to whole wheat flour.
The closest thing we found in the United States to the Austrian flour was the Pure White Rye from Bay State Milling.
If you have your own grain mill, we also developed a method to turn other coarser American rye flours into something resembling the magic Austrian flour, which you’ll find on page 226 in Volume 2 of Modernist Bread.
To be clear, we don’t think dense rye bread is bad. In fact, we enjoy it. But if you’re interested in trying to replicate our Austrian flour experience and you live in the United States, most supermarket rye flour won’t make the cut. That’s why it’s important to know how finely a rye flour is milled.
Understanding the nuances of rye flour, including grain quality, milling techniques, and particle size, can empower you with greater control over the outcome of your next loaf of rye bread or broaden your horizons about what rye bread can be. As always, we would love to see your baking results, so be sure to tag us on social media. If you’re looking for any rye recipes to try, you can find a wide variety of recipes in Modernist Bread or Modernist Bread at Home, including 100% High-Ryes, German Sunflower Seed Rye Bread, Farmer’s Bread, Landbrot with Pressure-Caramelized Cherries and Almonds, and more.
Learn more about rye and how it functions in bread in our blog How Rye Works.