Wheat: The Oldest Grain
It could start in your homebrewery, when you’re deciding how to mill the grain. It could start at your local homebrew shop, where wheat malt and wheat malt extract sit on the shelves, waiting to be made in to beer. It could start in the first century in Germany, where the modern style of wheat beer began to emerge. Or, it could start where I’m going to start the story — in 8,500 BC in the Fertile Crescent.
The Evolution of Wheat
A modern supermarket holds thousands of food products from domesticated plants. There are foods derived from roots, tubers, stems, stalks, leaves, flowers, fruits and seeds (including nuts, legumes and — of course — grains). Each one of the plants that supply the food product was once wild, but was domesticated at a certain time and place. As it turns out, the first plant to be domesticated was wheat.
Einkorn One of the ancestors of modern wheat is a species called einkorn (Triticum monococcum). Einkorn is a species of grass, like modern wheat. Unlike modern wheat, however, einkorn has a hull (like barley) and is diploid. (Diploid species are those that contain two sets of chromosomes. Most modern wheat is hexaploid, having six sets of chromosomes.)
Around 8,500 BC in the Fertile Crescent (a region — centered around the Tigris and Euphrates rivers — that occupies part of modern day Turkey, Syria and Iraq), wild einkorn (T. monococcum boeticum) was domesticated when a series of mutations were selected for by humans in the area.
The first mutation selected for was one that kept the wheat “head” — where the kernels are — from shattering. In wild einkorn, the head shatters to disperse its seeds. However, in einkorn (and many grass species) a single mutation leads to a plant in which the head stays intact. In the wild, this is detrimental as the seeds do not get dispersed. However, humans in the Fertile Crescent collected these easy-to-harvest mutants. Seeds from these mutants were then planted, at first perhaps accidentally when stray kernels fell onto the ground, and people began growing them preferentially. Further domestication involved selecting for faster-maturing strains, larger kernels and many other features. This lead to domesticated einkorn (T. monococcum monococcum). Einkorn was rediscovered in the 1970’s in France, where it was still being grown to be made into porridge.
Emmer and Durum
Here the wheat story backtracks a bit. About a million years before humans domesticated einkorn wheat, a wild wheat (T. urartu) and a species of goat grass (Aegilops speltoides) naturally hybridized. The result was a wild species of tetraploid grass (T. turgidum). (Tetraploid means four sets of chromosomes). This tetraploid species later became the second species of wheat domesticated and is called emmer wheat (T. turgidum dicoccum). Emmer wheat was originally a hulled wheat like einkorn, but unhulled (also called free-threshing or naked) forms appeared later. Emmer is still available in parts of Europe under its Italian name faro.
Emmer was the most widely planted type of wheat until early Roman times, when it was largely supplanted by durum wheat and modern bread wheats. Durum wheat (T. turgidum durum) is another domesticated subspecies of T. turgidum, the tetraploid species that gave rise to emmer. Durum is a huskless wheat with a high protein content that is still widely available today as it is regarded as the best wheat for pasta making. (In 1875, plant breeders hybridized durum wheat and rye to make triticale, a grain that combined the productivity and disease-resistance of wheat with the vigor of rye.)
Spelt and Bread Wheat
The final big step leading to modern wheat happened just 8,000 years ago, around 6,000 BC, when our tetraploid wheat species (T. turgidum) hybridized with another species of goatweed (Aegilops tauschii) to make a hexaploid wheat (T. aestivum). This species gave rise to spelt (T. aestivum spelta, husked), modern bread wheat (T. aestivum aestivum, unhusked) and club wheat (T. aestivum compactum, unhusked). Scientists hypothesize that modern bread wheat evolved, through artificial selection, from a variety of spelt.
Scientists have crossed T. turgidum and A. tauschii in the laboratory and recreated the historic hybridization. The result is a hulled wheat, much like spelt, which meshes well with the previous hypothesis. Evidence for the “big picture” of the evolution of wheat, presented in brief here, comes from the analysis of wheat kernels found associated with human archaeological remains and the genetic analysis of the modern genomes of wheat and goat grass species.
The success of modern bread wheat is largely due to its gluten content. Gluten is a protein found concentrated in the outer layers of the wheat kernel. Gluten is cohesive (it sticks to itself) and insoluble in water. In bread wheats, the sticky gluten is also elastic — allowing it to capture gas bubbles rising in wheat dough to make leavened bread. Durum wheat has sticky gluten, but its elasticity is not sufficient to make rising breads. Einkorn wheat, for comparison, has a fairly non-sticky, non-elastic gluten.
Today, about 90% of all wheat grown is (hexaploid) bread wheat; the remaining 10% is mostly (tetraploid) durum wheat, for pasta making. Wheat is the third most cultivated grain in the world — behind maize and rice, but ahead of barley (in fourth place). A large amount of maize becomes food for livestock or is used in the production of ethanol for fuel use. In contrast, almost all rice harvested is for human consumption. Wheat is used for human food, livestock feed and brewing.
As homebrewers, of course, it’s the brewing we’re most interested in. From a brewing standpoint, a quick summary of the evolution of wheat might be that its kernels got bigger, its hull disappeared and it gained sticky gluten. The first thing is good; the other two, as we will see, can be problematic for brewers.
Wheat Malting
Both malted and unmalted wheat are used in brewing. Wheat destined to be malted is hexaploid wheat. Durum and einkorn wheat are not malted. Malted wheat is most often winter wheat, as winter wheat has less protein than spring wheat, but some malt made from spring wheat can be found. Wheat is sometimes divided into hard and soft wheats and either may be malted. Hard wheats are usually higher in protein (and gluten).
Because wheat kernels have no husk, wheat takes up water faster than barley and hence the steeping stage of malting occurs more quickly. Because wheat kernels are larger than barley kernels, it takes longer to dry them in the kilning stage. Typically, the drying is done at a lower temperature than with barley malts. The extra time in the kiln, however, means that wheat base malts are slightly darker (~2.4–3.2 °L) than the lightest barley malts (1.2–2.0 °L). A clear beer made with mostly wheat (say, 70% wheat and 30% barley) would be golden in color, a hair darker than a Pilsner. Turbidity in wheat beer, though, makes wheat beers seem “whiter” than they are.
Wheat Brewing Products
At your homebrew shop, you will likely find two kinds of wheat malt —red wheat malt and white wheat malt. (These may be spring or winter, hard or soft.)
Raw kernels of red wheat are darker than that of white wheat kernels as red wheat contains more phenolic compounds and browning enzymes than white wheat. However, as most of the color in wheat malt comes from kilning, both types of wheat malt add about the same color depth to beer. (Wheat beers made with red wheat don’t, for example, turn out amber-colored.) White wheat kernels are a bit plumper than red wheat kernels.
Traditionally, German weissbiers and Belgian wits were made with red wheat, although many brewers use red and white wheat interchangeably. Ashton Lewis — brewmaster at Springfield Brewing, technical editor of BYO and GABF medal winner for his American wheat beer — says, “I see differences in the haze stability in beers made with red and white wheats. I prefer the red varieties because the haze stays around longer.”
Raw wheat (sometimes called wheat “berries”) can be found at many homebrew shops and nearly all health food stores. Any type you find except durum is likely acceptable for brewing. Whereas German wheat beers are always made from malted wheat (as the Reinheitsgebot prescribed that only malted grain be used in brewing), Belgian wheat beers often contain unmalted wheat. Traditional lambics, for instance, were made from around 65% malted barley and 35% unmalted wheat.
Most malting companies make red and white wheat malts. Weyermann (a German malting company) also makes a few types of wheat specialty malts, including a dark wheat malt (5.8–7.3 °L), a caramel wheat malt (38–49 °L) and chocolate wheat malt (300–450 °L). Brian Peters — a brewer at The Bitter End, a brewpub in Austin, Texas — says, “Homebrewers should try out some of the wheat specialty malts. Because of the difference in protein content, wheat specialty malts have a different flavor from barley malts.” The Bitter End’s wheat bock (Austintinus) showcases some of these darker malts and is delicious.
Wheat malt extracts are also available. Most wheat malt extracts are made from a mixture of wheat and barley malts, but some 100% wheat extracts are available. Usually, a wheat malt extract will have a minimum of 50% wheat and extracts with 65–70% wheat are common, especially when sold as extracts for German wheat beers. Frequently, the percentage of wheat is given on the package.
Wheat in the Brewhouse (or Big, Hard, Naked and Sticky)
Wheat is different from barley in several ways. Compared to barley, wheat has larger kernels, harder kernels, no husk and more gluten. Wheat also contains more protein overall than barley. These differences chart the course for how to treat wheat differently than barley when brewing.
High Protein Wheat has more protein than barley, and excess protein can cause haze in beer. In high-protein barley malts (such as six-row barley malts), protein is frequently diluted by using low protein adjuncts (such as rice or corn). However, in wheat beers, the usual response to the protein levels is to accept, or even embrace, the resulting turbidity. A German hefeweizen, for example, is supposed to be cloudy. So is a Belgian wit. A few Belgian beers combine wheat malt and refined sugars (a zero protein adjunct) added as a kettle adjunct.
Hard Kernels Wheat is hard to mill if you do it by hand. It’s not impossible to do — I brew a 20-gallon (76-L) batch of lambic every year and crack the grains with my unmotorized mill — but it takes a little more effort.
Big and Naked Wheat kernels are larger than barley kernels, but don’t have a husk. It’s reasonable to assume that you might want to adjust your mill to account for this. Ashton Lewis says, “I tighten up my mill a bit and grind the wheat a bit finer.” Conversely, Brock Wagner of St. Arnolds Brewing (Houston, Texas) says, “We loosen our mill a little.”
The finer you grind, the more extract you can get from your malt. However, you also run the risk of a stuck mash when running off the wort. A little finer or little coarser grind is not a big deal if you match your crush type to your lautering plan (see below).
Sticky Glucans
The glucan content of wheat is what gives it its reputation for being difficult to lauter. However, this reputation may be overstated. None of the brewers I spoke to had any troubles with their wheat beers. If you perform a mash out — and insulate your mash tun so the temperature doesn’t drop while sparging — you will likely not encounter any problems collecting your wort. To perform a mash-out, just stir boiling water into your mash and raise its temperature to 168 °F (76 °C). Let the mash sit for 5 minutes before beginning to recirculate.
Running off the wort at a reasonable speed will also help you avoid problems. Aim to collect your wort at a steady rate over 60–90 minutes. If you wish, you can employ a step mash with a rest in the beta-glucanase range (104–122 °F/40–50 °C) for 15–30 minutes. For even more insurance, you can add rice hulls to your mash if you have over 60% wheat.
Raw wheat can also be used in the mash. Raw wheat can be used in a single infusion or step mash. Or, the raw wheat portion can be boiled with a little malt as is done in a cereal mash.
Boil
Wheat worts contain a lot of protein and most traditional styles of wheat beer employ a 90-minute or longer boil. The length of the boil ensures good hot break formation.
German hefeweizens and Belgian wits are light-colored beers. When making them, some homebrewers are wary of an extended boil — afraid that they will caramelize sugars in the wort and darken the wort excessively. However, a 90–120 minute full wort boil of a light-colored wheat wort will not darken to the extent that is not representative of that style.
Boiling a concentrated wort — as when making a stovetop extract beer — can lead to copious amounts of wort darkening. (Back in the day, my first hefeweizen turned out red when I boiled all my malt extract in around 1.5 gallons (5.7 L).) If you’re making a wheat beer from extract, add only about one quarter to one third of the extract initially. Boil the hops in this wort, then add the remaining malt extract in the final 15 minutes. If you wish to make a turbid (cloudy) beer, don’t add Irish moss during the boil.
Wheat Flavor
In most wheat beers, the flavor of wheat is paired with other flavors. In German weissbiers, wheat mingles with the banana and clove from the yeast. In a Belgian wit, the wheat is paired with spices and in lambics, the beer is soured. And, wheat beers are a favorite base beer for fruit flavors. Here are a couple recipes that offer slight twists on common wheat styles.
Dreherweizen
(5 gallons/19 L, all-grain)
OG = 1.048 FG = 1.012
IBU = 22 SRM = 6 ABV = 4.7%
This is a standard hefeweizen with Vienna malt substituted for pale barley malt and a hint of hop flavor from Amarillo hops. The color depth is only slightly deeper than a standard hefe — a deep golden with a hint of orange.
Ingredients
7 lbs. (3.2 kg) red wheat malt
3 lbs. (1.4 kg) Vienna malt (4 °L)
5.4 AAU Hallertau hops (60 mins) (1.4 oz./38 g of 4% alpha acids)
0.25 oz. (7.1 g) Amarillo hops (15 mins)
Wyeast 3068 (Weihenstephan Wheat) or White Labs WLP300 (Hefeweizen) yeast (1 qt./1 L starter)
1 cup corn sugar (for priming)
Step by Step
Heat 3.75 gallons (14 L) of water to 115 °F (46 °C) and mash in grains in your kettle. Hold at 104 °F (40 °C) for 30 minutes. While the main mash is resting, pull a thick decoction equal to about one-quarter the volume of the main mash and place it in a separate pot. Heat decoction to 162 °F (72 °C) and hold for 5 minutes, then boil decoction for the remaining time in the main mash’s 30 minute rest. (Stir decoction constantly.) Stir decoction into main mash and apply direct heat, bringing the mash temperature to 156 °F (69 °C) and hold for 45 minutes. Transfer mash to lauter tun and add boiling water to raise temperature to 170 °F (77 °C). Recirculate wort for 20 minutes and collect about 5.5 gallons (21 L) of wort. Add 1 gallon (3.8 L) of water and boil wort for 90 minutes, adding hops at times indicated. Cool wort, aerate and pitch yeast. Ferment at 70 °F (21 °C). Prime with corn sugar and bottle.
Belgian Cowboy
(5 gallons/19 L, partial mash)
OG = 1.049 FG = 1.012
IBU = 19 SRM = 6 ABV = 4.7%
A fairly standard Belgian witbier that’s perhaps a bit less spicy but a bit more tangy than most (but not by much). A good first time partial mash recipe for extract brewers.
Ingredients
3.3 lbs. (1.5 kg) Coopers liquid wheat malt extract (late addition)
2.5 lbs. (1.1 kg) 6-row pale malt
2.0 lbs. (0.91 kg) wheat malt
0.5 lbs. (0.23 kg) Weyermann sour malt
0.75 lbs. (0.34 kg) rolled or flaked oats
5 AAU Styrian Goldings (60 mins) (1 oz./28 g of 5% alpha acids)
Wyeast 3944 (Belgian Wit) or White Labs WLP410 (Belgian Wit II) yeast
0.33 oz. (9.4 g) coriander
0.33 oz. (9.4 g) Curaçao orange peel
7/8 cup corn sugar (for priming)
Step by Step
Place cracked grains and oats in a large nylon steeping bag. In your brewpot, heat 2 gallons (7.6 L) of water to 166 °F (74 °C). Submerge grain bag and hold the temperature of this partial mash between 148 and 155 °F (64– 68 °C) for 60 minutes. In a separate pot, heat 0.5 gallons (1.9 L) of water to 170 °F (77 °C). Lift grain bag out of brewpot and place in colander over brewpot. Rinse grains with water from second pot. Boil this wort for 60 minutes, adding hops when wort begins boiling. In the final 15 minutes of the boil, stir in liquid malt extract and add spices (Stir extract well, but keep the clock running on the boil time.) Cool wort and transfer to fermenter. Top up to 5 gallons (19 L) with water. Aerate wort and pitch yeast. Ferment at 70 °F (21 °C) for one week. Cold condition, if practical, for two weeks. Then, prime with corn sugar and bottle.
