How the coffee industry is about to get roasted by climate change


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Climate change could severely impact the world’s coffee-producing nations and turn a cup of decent java into a luxury in the years to come.
(Shutterstock)

Sylvain Charlebois, Dalhousie University

Fall is always a good time to create new habits, and coffee chains know it.

These days, they are desperately trying to find any excuse to get you to drink their java.

Many chains used National or International Coffee Day, just passed, as a reason to offer their coffee at a discount, or even for free — with some conditions, of course.

For restaurant operators, there’s no better hook than coffee to get repeat business. It’s a great scheme that seems to be working for some. Given what’s looming on the horizon, however, offering free coffee may no longer be an option for businesses.

Coffee demand around the world is shifting. Europe still accounts for almost one third of the coffee consumed worldwide, but China has doubled its consumption in just the last five years.

As for Canada, numbers remain robust as more than 90 per cent of adult Canadians drink coffee. Several recent studies suggest coffee is a healthy choice, possibly one factor in the rise in coffee drinkers.

Either way, demand is strong in most Western countries, which puts more pressure on coffee-producing countries. However, as climate change looms, there’s a real threat to coffee’s global success story.

Coffee grown in more than 60 countries

Coffee is the most traded commodity in the world after oil.

Coffee beans are grown in more than 60 countries and allow 25 million families worldwide to make a living. Brazil is by far the largest producer, followed by Vietnam and Colombia.

Globally, 2017 could be a record year, as the world will likely produce well over 153 million 60-kilogram bags of coffee. Coffee futures are down as a result, but we are far from seeing a bumper crop.

Production has been modestly shifting over the past few years. With good rainfalls in Brazil and favourable weather patterns in other regions of the world, Mother Nature has so far spared coffee growers, but their luck may be running out.

Despite not being a staple in any diet, coffee is big business. At the farm gate, coffee is worth over US$100 billion. In the retail sector, the coffee industry is worth US$10 billion.

But there is growing consensus among experts that climate change will severely affect coffee crops over the next 80 years. By 2100, more than 50 per cent of the land used to grow coffee will no longer be arable.

Ethiopia could be profoundly affected

A combination of effects, resulting from higher temperatures and shifting rainfall patterns, will make the land where coffee is currently grown unsuitable for its production.

According to the National Academy of Science, in Latin America alone, more than 90 per cent of the land used for coffee production could suffer this fate. It’s estimated that Ethiopia, the sixth largest producer in the world, could lose over 60 per cent of its production by 2050. That’s only a generation from now.

As climate conditions become critical, the livelihoods of millions of farmers are at risk and production capacity is jeopardized. Other potential contributors to this predicted downfall are pests and diseases.

A Ugandan coffee farmer inspects his plants in 2015. Coffee is the lifeblood of many families in Uganda but their success is threatened by climate change.
(AP Photo/Stephen Wandera)

With climate change, pest management and disease control are serious issues for farmers who cannot afford to protect their crops. More than 80 per cent of coffee growers are peasant farmers.

Pests and diseases will migrate to regions where temperatures are adequate for survival, and most farmers won’t be ready. Many will simply choose to grow other crops less vulnerable to climate change. Others may attempt to increase their coffee production, but the quality will almost certainly be compromised.

Coffee quality will suffer

Higher temperatures will affect the quality of coffee. Higher-quality coffee is grown in specific regions of the world where the climate allows the beans to ripen at just the right time. Arabica coffee, for example, which represents 75 per cent of world coffee production, is always just a few degrees away from becoming a sub-par product.

This will undoubtedly affect coffee prices and quality for us all. Thanks to the so-called Starbucks Effect, the quality of the coffee we now enjoy is far superior to that of just a decade ago. Good beans may become more difficult to procure in the future.

Right now, coffee futures are valued at US$1.28 per pound and are being exposed to downward pressures. At this rate, the record price of US$3.39 per pound, set in 1977, could return in just a few years.

The coffee wars we are seeing are not just about gaining market shares and getting consumers hooked on java. They are also about how we connect with a crop that is under siege by climate change.

Short of fighting climate change, we could be forced to alter our relationship with coffee. As current coffee-producing countries attempt to develop eco-friendly methods and embrace sustainable practices, Canada could be the next country where coffee is actually grown, not just roasted.

Within the next decade, with climate change and new technologies, perhaps producing coffee beans will be feasible in Canada. After all, if Elon Musk thinks we can start colonizing Mars by 2022, why can’t we grow coffee in Canada?

The ConversationSo if a coffee chain is offering free coffee, take it. It won’t be long before coffee could become a luxury.

Sylvain Charlebois, Professor in Food Distribution and Policy, Dalhousie University

This article was originally published on The Conversation. Read the original article.

The science behind… coffee!

Brewing a great cup of coffee depends on chemistry and physics

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What can you do to ensure a more perfect brew?
Chris Hendon, CC BY-ND

Christopher H. Hendon, University of Oregon

Coffee is unique among artisanal beverages in that the brewer plays a significant role in its quality at the point of consumption. In contrast, drinkers buy draft beer and wine as finished products; their only consumer-controlled variable is the temperature at which you drink them.

Why is it that coffee produced by a barista at a cafe always tastes different than the same beans brewed at home?

It may be down to their years of training, but more likely it’s their ability to harness the principles of chemistry and physics. I am a materials chemist by day, and many of the physical considerations I apply to other solids apply here. The variables of temperature, water chemistry, particle size distribution, ratio of water to coffee, time and, perhaps most importantly, the quality of the green coffee all play crucial roles in producing a tasty cup. It’s how we control these variables that allows for that cup to be reproducible.

How strong a cup of joe?

Besides the psychological and environmental contributions to why a barista-prepared cup of coffee tastes so good in the cafe, we need to consider the brew method itself.

Science helps optimize the coffee.
Chris Hendon, CC BY-ND

We humans seem to like drinks that contain coffee constituents (organic acids, Maillard products, esters and heterocycles, to name a few) at 1.2 to 1.5 percent by mass (as in filter coffee), and also favor drinks containing 8 to 10 percent by mass (as in espresso). Concentrations outside of these ranges are challenging to execute. There are a limited number of technologies that achieve 8 to 10 percent concentrations, the espresso machine being the most familiar.

There are many ways, though, to achieve a drink containing 1.2 to 1.5 percent coffee. A pour-over, Turkish, Arabic, Aeropress, French press, siphon or batch brew (that is, regular drip) apparatus – each produces coffee that tastes good around these concentrations. These brew methods also boast an advantage over their espresso counterpart: They are cheap. An espresso machine can produce a beverage of this concentration: the Americano, which is just an espresso shot diluted with water to the concentration of filter coffee.

All of these methods result in roughly the same amount of coffee in the cup. So why can they taste so different?

When coffee meets water

There are two families of brewing device within the low-concentration methods – those that fully immerse the coffee in the brew water and those that flow the water through the coffee bed.

From a physical perspective, the major difference is that the temperature of the coffee particulates is higher in the full immersion system. The slowest part of coffee extraction is not the rate at which compounds dissolve from the particulate surface. Rather, it’s the speed at which coffee flavor moves through the solid particle to the water-coffee interface, and this speed is increased with temperature.

The Coffee Taster’s Flavor Wheel provides a way to name various tastes within the beverage.
Specialty Coffee Association of America, CC BY-NC-ND

A higher particulate temperature means that more of the tasty compounds trapped within the coffee particulates will be extracted. But higher temperature also lets more of the unwanted compounds dissolve in the water, too. The Specialty Coffee Association presents a flavor wheel to help us talk about these flavors – from green/vegetative or papery/musty through to brown sugar or dried fruit.

Pour-overs and other flow-through systems are more complex. Unlike full immersion methods where time is controlled, flow-through brew times depend on the grind size since the grounds control the flow rate.

The water-to-coffee ratio matters, too, in the brew time. Simply grinding more fine to increase extraction invariably changes the brew time, as the water seeps more slowly through finer grounds. One can increase the water-to-coffee ratio by using less coffee, but as the mass of coffee is reduced, the brew time also decreases. Optimization of filter coffee brewing is hence multidimensional and more tricky than full immersion methods.

What do they know that we don’t?
Redd Angelo on Unsplash, CC BY

Other variables to try to control

Even if you can optimize your brew method and apparatus to precisely mimic your favorite barista, there is still a near-certain chance that your home brew will taste different from the cafe’s. There are three subtleties that have tremendous impact on the coffee quality: water chemistry, particle size distribution produced by the grinder and coffee freshness.

First, water chemistry: Given coffee is an acidic beverage, the acidity of your brew water can have a big effect. Brew water containing low levels of both calcium ions and bicarbonate (HCO₃⁻) – that is, soft water – will result in a highly acidic cup, sometimes described as sour. Brew water containing high levels of HCO₃⁻ – typically, hard water – will produce a chalky cup, as the bicarbonate has neutralized most of the flavorsome acids in the coffee.

Ideally we want to brew coffee with water containing chemistry somewhere in the middle. But there’s a good chance you don’t know the bicarbonate concentration in your own tap water, and a small change makes a big difference. To taste the impact, try brewing coffee with Evian – one of the highest bicarbonate concentration bottled waters, at 360 mg/L.

The particle size distribution your grinder produces is critical, too.

Every coffee enthusiast will rightly tell you that blade grinders are disfavored because they produce a seemingly random particle size distribution; there can be both powder and essentially whole coffee beans coexisting. The alternative, a burr grinder, features two pieces of metal with teeth that cut the coffee into progressively smaller pieces. They allow ground particulates through an aperture only once they are small enough.

Looking for a more even grind.
Aaron Itzerott on Unsplash, CC BY

There is contention over how to optimize grind settings when using a burr grinder, though. One school of thought supports grinding the coffee as fine as possible to maximize the surface area, which lets you extract the most delicious flavors in higher concentrations. The rival school advocates grinding as coarse as possible to minimize the production of fine particles that impart negative flavors. Perhaps the most useful advice here is to determine what you like best based on your taste preference.

Finally, the freshness of the coffee itself is crucial. Roasted coffee contains a significant amount of CO₂ and other volatiles trapped within the solid coffee matrix: Over time these gaseous organic molecules will escape the bean. Fewer volatiles means a less flavorful cup of coffee. Most cafes will not serve coffee more than four weeks out from the roast date, emphasizing the importance of using freshly roasted beans.

One can mitigate the rate of staling by cooling the coffee (as described by the Arrhenius equation). While you shouldn’t chill your coffee in an open vessel (unless you want fish finger brews), storing coffee in an airtight container in the freezer will significantly prolong freshness.

The ConversationSo don’t feel bad that your carefully brewed cup of coffee at home never stacks up to what you buy at the café. There are a lot of variables – scientific and otherwise – that must be wrangled to produce a single superlative cup. Take comfort that most of these variables are not optimized by some mathematical algorithm, but rather by somebody’s tongue. What’s most important is that your coffee tastes good to you… brew after brew.

Christopher H. Hendon, Assistant Professor of Computational Materials and Chemistry, University of Oregon

This article was originally published on The Conversation. Read the original article.