From gladiators to Grolsch - a story about barley
Inspired by Kew's Incredibles Festival, Sarah Cody shares some lesser-known facts about barley, one of the world’s favourite crops and one of the 29 key crops of the Millennium Seed Bank and the Global Crop Diversity Trust's Adapting Agriculture to Climate Change project
I suspected a title mentioning gladiators and beer would pique your interest! Now before you slip into a reverie about Russell Crowe, encased in armour and fighting off a dozen gladiators, let me bring you back to earth (I promise it’ll be worth it) to tell you about the incredible barley.
Hordeum vulgare, as it is known in Latin, is the fourth most important cereal crop in the world after wheat, maize, and rice. It is mainly grown to feed livestock but second to this is its importance in malting for beer brewing and whiskey making. Those savvy Ancient Egyptians caught on to the idea early and archaeological evidence of barley grains found in the great pyramids of Egypt 5,000 years ago, as well as in ancient Egyptian and Sumerian writings, suggest that our ancestors have been enjoying the good stuff for millennia.
The cultivation of barley occurred in the Fertile Crescent, the region surrounding modern day Israel and Jordan, around 8,000 BC. Its wild ancestor is Hordeum vulgare subsp. spontaneum and while the two grasses are very closely related, the main difference between them is found in the spikes that hold the seeds. In wild barley they are brittle, which means that once the seed matures the spikelets separate easily enabling seed dispersal, whereas cultivated barley has non-shattering spikes which means that the plant holds onto the mature seeds, making them much easier to harvest. (This distinction between wild and cultivated forms is mirrored in many other crops.)
The development of non-shattering spikes
This is how it all came about. Domestication begins with the harvesting of seeds from a wild population of plants. Some plants will have lost the natural ability to shed their seeds when ripe and these were more likely to be collected and re-sown than those plants whose seeds were already scattered. My seed collecting friends have confirmed this – it is far easier to pull the seeds off a plant than to scrounge around on the ground for the matured fallen seed which, supposing it even belonged to the plant you’re interested in, could already be mouldy or pest-ridden. So, generations later, this non-shattering characteristic would become fixed in the population, and today one of the most striking features of nearly all crop plants is that, unlike their wild relatives, they retain their seeds and depend almost entirely on humans to gather and sow their seeds. Indeed, many crops would die out if there were no humans to sow or plant them.
Barley is a tough cookie and makes for a tough gladiator too
From arctic latitudes and alpine altitudes to salty desert oases, barley can grow in extreme environments where other crops are unable to survive. It is typically a temperate crop but it can also be found growing in tropical countries where poor farmers are able to benefit from barley’s resilience to hostile, dry, environments. In places like Nepal, Tibet and Ethiopia farmers grow barley on mountain slopes at higher elevations than other cereals and in the dry areas of the Middle East and North Africa, barley is often the only suitable crop. The key producers of barley today are Russia, Canada, Germany, France, Ukraine, Spain, Turkey, UK, Australia, USA and Denmark.
As well as being a fodder and malting crop, barley is also cultivated for direct human consumption. Its value as a high energy carbohydrate source has been documented since Roman times when gladiators were called hordearii, literally meaning “barley men”. Gladiators would fatten up on a diet of simple carbohydrates such as barley so that when they entered the ring in a battle to the death, the extra layers of subcutaneous fat would protect them from cut wounds and shield nerves and blood vessels. Apparently fat gladiators made for a more spectacular show. Gladiators wounded only at the fatty layer would be able to keep on fighting and bloody, maimed, unrelenting chubby gladiators were exactly the kind of thing Romans went wild over. In addition to being a gladiator-worthy carbohydrate source, certain barleys are also remarkably high in protein, such as some Ethiopian varieties which contain up to 18% protein.
A spiritual experience (and this time I’m not talking about whiskey!)
Today, barley is eaten in several remote parts of the world such as Tibet and parts of North Africa where nothing else can grow. Tsampa, a delicious Tibetan dish made with roasted barley and prepared with tea, is consumed daily in villages throughout Tibet.
For Tibetans, the preparation and consumption of tsampa is a sacred and ritualised process where the ingredients barley flour, butter, tea and cheese represent the four elements of the earth – namely earth, fire, water, and wind. When making tsampa, the mixture of these ingredients must form a pile that reaches higher than the mouth of the bowl. This pile symbolises the universal mountain of Tibetan Buddhism, which is a representation of the entire world. Before the meal, Tibetans chant and make offerings to all sentient beings by throwing small bits of tsampa into the air or on the ground. In Tibetan culture, barley flour is also used to make incense offerings to the mountain gods and often forms a part of religious offerings in temples.
Barley improvement through the use of Crop Wild Relatives
Like all crops, barley has to contend with pests, diseases and environmental stresses such as drought, salinity and climate change. Changes in drought and salinity levels, which are expected to worsen with climate change, will not just affect beer production but will also impact on the food supply of those people who depend directly on barley as a staple part of their diet. Lowering greenhouse gas emissions is a necessary step towards stalling the effects of climate change but, in addition to this, we need to arm ourselves against climate change by adapting our crops to future climate scenarios. The wild relatives of barley are a rich source of genetic diversity which has great potential for barley improvement. Drought- and salt-tolerant genes have been identified in the crop wild relative Hordeum vulgare subsp. spontaneum and disease resistance has been found in Hordeum bulbosum. Other traits from H. bulbosum, such as perenniality, have the potential to alter the crop for a more sustainable production and maintenance of genetic diversity.
The Adapting Agriculture to Climate Change project, jointly organised by the Millennium Seed Bank and the Global Crop Diversity Trust, aims to protect, collect and prepare the wild relatives of 29 key food crops, including barley. By making these seeds available to pre-breeders the useful traits they hold can be used to improve crops and therefore safeguard our future food security.
And finally, something for our furry friends
Those of you with pet cats will have noted their occasional craving for grass. Rather than have them nibbling on your houseplants, Cat grass (Hordeum vulgare subsp. variegata) is a variety of barley which has been cultivated to satisfy the highly sophisticated tastebuds of our feline companions. It makes quite an attractive houseplant too!
- Sarah -