Wednesday, November 20, 2019

Farm Bulletin: Return to Durum


James Robinson, an organic dairy farmer in Cumbria, recently wrote that farmers are always playing the long game. A female calf born today will not enter his milking herd for two years, and it will be two years after that before she will return much profit to the farm. Anthony and Carol Boutard have been developing varieties of organic corn, grains and other crops at Ayers Creek Farm, a process that can take several years before they'll know whether it fits their rigorous requirements. 

Sixteen years ago, we started growing durum, also known as hard amber wheat, for making parched green wheat, or frikeh. The original Economic Botany paper that described the process specified durum, so we abided. Durum is used for couscous, bulgur, fregula, tarhana and flatbreads, and is grown extensively in the Middle East and India. It is the region’s grain at hand, which explains its incidental use as a parched grain. The variety we were growing at the time had a short straw, so the heads were hard to harvest by hand, and it also turned out to be very susceptible to the strain of wheat rust that spread through the valley five years later. We abandoned the durum and started using a soft red wheat, which is a very long straw or tall variety, and resistant to that strain of rust. As we were parching the heads before maturation of the grain, the protein structure of the mature grain was unimportant. Still, we really loved the durum. A couple of years ago, we tried a different strain of durum and it has grown nicely.

Durum wheat at Ayers Creek Farm.

Botanically, durum is a cultivated species developed from wild emmer wheat, about 7,000 years ago. It is a very different beast from the hard and soft bread wheats, which were developed from wild einkorn and two other grass species. Durum and emmer have four copies of their seven chromosomes, and thus are termed a tetraploid species. Bread wheat and spelt have six copies, or hexaploid. Corn is a simple diploid. In the case of durum and bread wheat, the ploidy level simply points to two different ancestries. Although durum has higher protein content, those proteins do not produce as strong a dough as bread wheat. For this reason, it is used for pastas and flatbreads.

The milling fragrance and quality of durum are distinct as well. Because the grain is so hard, it does not mill to a flour using a traditional stone mill. Instead, the stones yield a semolina which we pass through a #26 bolt, removing most of the bran. For comparison, our cornmeal passes through #14 bolt. All foods have a standard of identity that is defined by the Food and Drug Administration under 21CFR137. Cornmeal must pass through a #12 bolt. Farina and semolina are defined as the fraction that passes through a #20 bolt. Flour is the fraction that passes through a #70 bolt. Consequently, our semolina and cornmeal are slightly finer than called for in their standards of identity. Before the development of wire cloth, sieves were made from loosely woven hemp, linen, cotton and silk. The bolt number is number of threads per inch, and silk produced the finest bolts. Mesh and bolt are synonymous, but we prefer the historical reference to a bolt of fabric, even though we now use sieves made of stainless steel wire.

La Faneuse by Émile Claus, 1896.

Our current durum strain is a much taller plant than the earlier sort, so we have a backup for parching if needed. We suspect it is also a much older strain. One of the key features of “green revolution” grains was reduction of straw length. When draft animals powered agriculture, the straw was as valuable as the grain. Long straw is also easier to scythe, then gather and stack (shock). The gathering and bundling of the plants was a task traditionally carried out by women and children. The captivating and sympathetic paintings of Émile Claus (1849-1924) and Léon Augustin Lhermitte (1844 to 1925) document the structure of field economy and society at the time. The early farmers in the west had neither labor nor machinery to harvest and transport the grain. Instead, they would “hog out” the grain by turning swine into the field and shipping the animals or cured hams.

Short straw varieties move through the combine more efficiently and are less prone to falling over (lodging) under heavy applications of fertilizers. On our farm, we appreciate the long straw because it is a good source of organic matter for crops following the grain and efficiency is not a hallmark of our endeavor anyway. We have also observed that the taller grains have fewer disease problems, possibly because of better air movement in the field as the leaves are higher above the ground. Carol has been using the milled durum in her sourdoughs at about 10 to 15 percent. It lends a pleasant sweetness to the bread as well as a moister crumb. Durum is also used to make Indian flatbreads such as chapati.

Read Anthony's response to a reader's question about short-straw wheat, pesticides and the Green Revolution.

Top: Harvest by Léon Augustin Lhermitte, 1874.

2 comments:

Troutgirl said...

I read a book recently that said the short straw varieties were specifically developed for warm climates like Mexico and India where rust is a serious problem. In your climate I'm guessing it's a wash.

Kathleen Bauer said...

Anthony Boutard responds:

Often the second half of a story is left out to create a myth, this is especially true with respect to the “Green Revolution.” Short-straw grains allow fungicidal sprays to penetrate into the planting more effectively, and that is one of the reasons they are favored. In the spring, spray buggies douse the field to control rust and tall plants would make it hard to get the penetration needed for effective control of the disease. Outside of organic systems, rust is managed by fungicides.

Tolerance for rusts in grains is genetic and I see no evidence that it is linked to straw length. Logically, it doesn’t make sense. Next spring, take a moment and see where the rust and other fungal diseases develop in the grain field. It is in the low areas where air flow is impeded. You can easily see the yellowing of the plants in these patches.

The problem with short-straw grains in an organic setting is the rain splashes soil and fungal inoculum onto the leaves and they take longer to dry out in the morning. Rust inoculum that blows into the field can thrive on the wet leaves and stems. Modern varieties are shin high, right in the splash zone. The durum, wheat and barley we grow are over waist high, so the foliage is well out of the splash zone. They do well in an organic setting. Bear in mind, these long-straw small grains have been grown successfully for eight millennia or more without employing a chemical arsenal. That is why we favor them.

The pernicious nature of spraying was driven home when we were planting melons and a neighbor sprayed his wheat field. As the buggy passed by, the brown ground spiders exited in a mass, crawling over our hands and legs. Thousands and thousands of refugees, an indelible moment, along with the chemical stench of the insecticide.

Unfortunately, pushing short-straw grain varieties that require heavy use of chemical inputs including fertilizers, fungicides, insecticides and herbicides have damaged the health of farmers and ecosystems, especially in countries such as India and Mexico with lax environment controls. The Bhopal disaster was the result of a factory producing carbaryl, the insecticide marketed as Sevin.

- Anthony Boutard