CDC Primepurple Wheat – An Ancient Grain for the Modern Brewer

Brewers seeking to broaden their recipe horizons with additions of ancient grains to the grist bill now have a new wheat strain to experiment with in the form of CDC Primepurple wheat.

Purple wheat is an ancient landrace of grain that was first found growing in Abysinnia (modern day Ethiopia) in the late 1890s. Archeological literature trace the origins of modern agriculture to the Fertile Crescent (modern day Iraq and Iran) and a time period of approximately 7000 BC. Early man’s efforts to domesticate wheat in the Fertile Crescent involved wheat variants emmer and einkorn. However, there is nothing mentioned in published literature supporting evidence of purple wheat in this area of the world. Why it was confined to Abysinnia remains uncertain, although literature does suggest that wheat can change its morphology due to extreme stresses. It is thus probable that a period of extreme heat or moisture stress at some point in early history resulted in wheat in the Abysinnia region developing a purple coloration in its kernels. In the early part of the 20th century, these newly discovered purple wheat kernels were taken to Germany and Russia for plant breeding trials and further investigation.

Plant scientists soon identified that the purple hue in the seeds was from an anthocyanin compound. Anthocyanins structurally consist of a 6 Carbon ring structure joined to a 3-Carbon group joined to another 6 Carbon ring structure. Anthocyanins are a sub-set of the phenol class of chemical compounds.   

In the 1950s, seeds of purple wheat made their way to New Zealand where they were grown as animal feed with the distinct kernel coloration used to distinguish the feed wheat from wheat intended for human consumption.

In the 1990s, purple wheat seeds arrived in Canada as part of a research project by the Saskatchewan Wheat Pool that sought to create a wheat varietal for the ethanol fuel industry. The plan was to follow the New Zealand strategy and use the purple coloration genetics to help delineate an ethanol fuel feed stock from wheat for human consumption. When the Wheat Pool abandoned this project, the breeding seeds were acquired by Saskatoon grain merchant Infraready Products. Company President Mark Pickard sought to carve out an export market for purple wheat in southeast Asia. The significant feature attracting the Asian market to purple wheat is the anthocyanin content suggested by medical literature to be effective in reducing free radicals in the human body. Working closely with plant breeder Dr. Pierre Hucl at the U of Saskatchewan, Infraready was able to cross breed a strain of purple wheat well suited to growing conditions on the Prairies. The developed strain was registered with the Canadian Crop Development Centre as CDC PrimePurple Wheat.

Fast forward to 2017 and that was when I first heard about CDC Primepurple wheat just as I was embarking on my M.Sc. degree studies through Heriot Watt University in Scotland. After discussions with Infraready Products, I decided to make this ancient grain the subject of my thesis project.

I obtained small quantities of torrified white spring wheat and CDC PrimePurple wheat from Infraready Products, as well as small quantities of un-torrified white and purple wheat. Thus far in the research, a series of small 8L batches of Belgian style wit beer have been brewed using a modified recipe obtained from the popular website Beersmith.com. The recipe was modified by reducing the amounts of orange peel and coriander seed. The objective in reducing these adjuncts was to determine if a taste or aroma difference could be detected by taste panels assessing the white wheat and purple wheat beers.

In total, one batch of beer was brewed with torrified white wheat and three batches with torrified purple wheat. One batch of beer was brewed with un-torrified white wheat and three batches with un-torrified purple wheat. All batches were fermented with Fermentis Wheat Beer yeast. All recipes contained 1 kg of wheat, 1.1 kgs 2-row pale malt, 0.25 kg steel cut oats, 115 grams rice hulls, Fuggles hops, crushed coriander seed, bitter orange peel and camomile tea leaf. The brewing regimen involved a brief protein rest at 50C, mashing at 68C for 75 minutes, boiling for 90 minutes. Hop addition was made with 60 minutes remaining in the boil. Remaining adjuncts were added with 5 minutes remaining in the boil. Target starting gravities on all batches was 1.040. The brewing system employed was a Grainfather unit.

Taste panels using the tetrad method have been able to detect a taste difference (72% accuracy) between beers made from torrified white and purple wheat. GC Mass Spec analysis on these beers conducted at KeyLeaf Laboratories in Saskatoon show that the beer made from torrified purple wheat contains approximately twice as much of each of the congener compounds 1-propanol, ethyl acetate, isopentanol and 1-butanol,2-methyl. What exactly is causing the metabolic pathways in the fermentation cycle to generate more congener compounds from purple wheat remains to be determined.

A recent taste panel using the tetrad method was able to detect a taste difference (68% accuracy) between beers made from un-torrified white and purple wheat. GC Mass Spec analysis on these beers is awaiting completion at KeyLeaf Laboratories in Saskatoon.

The final step in this brewing evaluation will be to create beer from white wheat and purple wheat using the complete recipe originally obtained from Beersmith. With elevated levels of orange peel and coriander in the recipe, will taste panels be able to still detect a flavor difference. This outcome will speak to the incentive a craft brewer might have to use CDC PrimePurple wheat in a recipe formulation.

Malcolm Bucholtz is a Regina resident and long-time home brewer and craft distillery consultant. He can be reached in Regina at (306) 216 6663 or at ProhibitionUniversity@gmail.com.

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