Author: Suse Coon

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Wednesday, June 11th, 2008 at 10:38 pm
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Food and Drink

The Story of Coffee

Do you need your ‘fix’ of coffee to get you through the day? Or does coffee make you ‘hyper’? What is coffee with the coffee taken out? It turns out this popular beverage has quite a history.

Coffee was first consumed in the 9th century, when it was discovered in the highlands of Ethiopia. Its popularity spread through the Moslem world to Europe, then the Americas and Asia.

Today, coffee is so popular worldwide that a number of economies rely on its production and export. In the same way as the term ‘hoovering’ has become synonymous with vacuuming, ‘going for a coffee’ has become synonymous with having a break, or meeting a friend for an informal chat. But buying coffee, either in a coffee shop to drink or in a grocer to make at home, is full of choices.

Coffee berriesProduction
Coffee berries, which contain the coffee bean, come from a small evergreen bush of the genus Coffea. The berries or cherries, as they are generally known, because they resemble ripe cherries, are usually picked by hand when the trees flower. Then they are sorted by ripeness and colour and the flesh is removed, leaving the seeds, better known as beans.

If the coffee is to be decaffeinated, this happens while they are still green.

Two main methods are used – solvent extraction or water extraction. The most commonly used solvents are trichloroethylene, methylene chloride or a similar chlorinated hydrocarbon. More recently, the less hazardous supercritical carbon dioxide has been used. Water extraction of caffeine claims several advantages including higher extraction rates, a purer product and no direct contact with solvents. The process takes approximately 10 hours resulting in green beans that are 99.9% caffeine-free, which is comparable with the solvent extraction method. Typically, jars of decaffeinated coffee don’t tell you which method has been used. The extracted caffeine can be sold to the pharmaceutical industry.

Coffee in the cooling tray immediately after it has been roastedRoasting.
What really gives coffee its aroma and flavour is the way the beans are roasted. Heat breaks down starches in the bean, changing them to simple sugars. As the roasting process continues, aromatic oils, acids, and caffeine weaken but other oils start to develop, in particular caffeol, which is largely responsible for coffee’s aroma and flavor.

the catalytic afterburner which is part of the roasterBrodies, who have been based in Musselburgh for the last 6 years have been producing great coffee and tea products since 1867. So we asked Ralph Lutton, the managing director, to explain the process.

“We “slow roast” our coffee using a method that will not have changed in the last 120 years,” explains Ralph. “This means we roast our coffees for between 12 and 14 minutes which allows the full range of flavour to develop.

“There have been a number of attempts to speed up the roasting process over the years, however, it is now generally accepted in the trade that “slow roasting” fully develops the flavours and characteristics, particularly of the best quality coffees. If you roast coffee too quickly you burn the outside of the bean and leave the inside raw, and if you take too long you bake the coffee and the freshness and character disappears up the chimney to leave a dull, flat tasting roast.”
Martin Starrs sampling the coffee as he roasts itThe beans are categorised according to colour. Darker roasts are generally smoother, because they have less fibre content and a more sugary flavour. Lighter roasts have more caffeine and a stronger, more bitter flavour.

“I am often asked what is the “best” coffee and that of course depends on your personal preferences, for example do you like sharp acidic flavours, or nutty flavours or perhaps a rich chocolatey taste or perhaps a blend of all of these? However, there is no doubt that the sooner you drink the coffee once it has left the roaster the better, and we keep as little stock as we realistically can to ensure our coffees are as fresh as possible when they are drunk.

“Each kilogram of coffee gives off 4.5 litres of gas (mainly co2) once it has been roasted and this causes packaging problems which we overcome by packing the coffee in packs with one way degassing valves. This allows us to pack the coffee whilst it is still fresh and ensures the coffee retains the sparkle of fresh roasted coffee.”

Before drinking, the coffee beans are ground to between 0.5 and 1.1 mm. The type of grind is actually named not after the method of grinding but after the brewing method for which it is to be used. So, Turkish grind is the finest, while percolator or French press are the coarsest.

Instant coffee involves yet another stage, during which the coffee is dissolved in water in order to extract it, then dried. You guessed! More choices! Two different drying methods are used, freeze and spray drying. The basic principle of freeze drying is the removal of water by sublimation. As the name suggests, wet coffee granules are frozen, then placed in a drying chamber where a vacuum is created. The drying chamber is warmed, so that frozen water in the coffee granules expands and is removed as water vapour. Spray Drying is more cost effective and produces fine, rounded particles. However, it is generally accepted that freeze drying provides a better taste.

Brewing Up
At last we are ready to brew – but even here there is a choice! Coffee may be brewed by several methods: boiled, steeped, or pressured.

Brewing coffee by boiling was the earliest method, and Turkish coffee is an example of this method. The beans are powdered with a mortar and pestle, then the powder is added to water and brought to a boil in a pot called a cezve or, in Greek, a briki. This produces very strong coffee with a layer of foam on the surface and is served in small cups!

Filter coffee machineMachines such as percolators or automatic coffeemakers brew coffee by gravity. In an automatic coffeemaker, coffee grounds are placed in a coffee filter. Boiling water drips through the ground coffee and absorbs its oils and essences. It then drips through the filter into a carafe or jug, leaving the used coffee grounds in the filter.

Coffee PercolatorIn a percolator, the pressure of the boiling water forces it into a chamber above a filter. The water then drips through the grounds and back into the main part of the container, repeating the process until shut off by a timer.

CafetiereCoffee may also be steeped in a French press or cafetière. Ground coffee and hot water are combined in a jug and left to brew. The coffee oils remain in the liquid, making it stronger and leaving more sediment than in filtered coffee. A plunger is then depressed keeping the coffee grounds at the bottom, while you pour.

Espresso machineThe espresso method forces hot, but not boiling, pressurized water through ground coffee, making a distinctive sound as it does so! The high pressure means that the liquid is more concentrated (as much as 10 to 15 times the amount of coffee to water as gravity brewing methods can produce) and has a more complex flavour. It should have a reddish-brown foam called crema that floats on the surface. It can be served alone as a ‘shot’ or as the watered down ‘café américano’ — a shot or two of espresso with hot water. The term ‘americano’ is thought to have been named after American soldiers in WW II who found the European espresso too strong. ‘Americano’ should be served with the espresso shots on top of the hot water to preserve the crema. Milk can be added in various forms to espresso: steamed milk makes a cafè latte, equal parts espresso and milk froth make a cappuccino, and a dollop of hot, foamed milk on top creates a caffè macchiato.

Depending on the type of coffee and method of preparation, the caffeine content of a single serving can vary greatly. On average, a single cup of coffee of about 207 millilitres (7 fluid ounces) or a single shot of espresso of about 30 mL (1oz) will contain the following amounts of caffeine:

* Drip coffee: 115–175 mg
* Espresso: 60 mg
* Brewed/Pressed: 80–135 mg
* Instant: 65–100 mg
* Decaf, brewed: 3–4 mg
* Decaf, instant: 2–3 mg

Yes but is it good for me or bad for me?
Coffee is a stimulant, hence it’s reputation as a pick-me-up, but, like all stimulants, it can have its problems.

While coffee appears to reduce the risk of Alzheimer’s disease, Parkinson’s disease, heart disease, diabetes mellitus type 2, cirrhosis of the liver and gout, it increases the risk of acid reflux and associated diseases. Some health effects of coffee are due to its caffeine content, for example, the antioxidants in coffee prevent free radicals from causing cell damage. Research suggests that caffeinated coffee can cause a temporary increase in the stiffening of arterial walls. Excess coffee consumption may lead to a magnesium deficiency and may be a risk factor for coronary heart disease. Some studies suggest that it may have a mixed effect on short-term memory, by improving it when the information to be recalled is related to the current train of thought, but making it more difficult to recall unrelated information.

About 10% of people with a moderate daily intake (235 mg per day) reported increased depression and anxiety when caffeine was withdrawn, and about 15% of the general population report having stopped caffeine use completely, citing concern about health and unpleasant side effects. Nevertheless, the mainstream view of medical experts is that drinking three 8-ounce (236 ml) cups of coffee per day (considered average or moderate consumption) does not have significant health risks for adults. Some people feel they benefit from the pick me up effect early in the day but avoid it nearer bed-time.

“Back in the 70s and 80s,” says Ralph, “the trade thought that there would be growth in the amount of decaffeinated coffee drunk and some people estimated that up to 50% of coffee consumption would soon be decaffeinated. In the mid 80s the figure for decaffeinated coffee consumption reached 15% but it has since dropped back and currently the figure is less than 5% in the UK.”

Coffee Did You KNow?
Caffeine Content in Common Foods and Beverages
Regular coffee (drip method, 5 oz) 60 – 180 mg
Tea, loose or bags (5 oz) 20 – 90 mg
Regular coffee (percolated, 5 oz) 40 – 170 mg
Iced Tea (12 oz) 67 – 76 mg
Regular coffee (instant, 5 oz) 30 – 120 mg
Hot Cocoa (5 oz) 2 – 20 mg
Decaffeinated coffee (drip method, 5 oz) 2 – 5 mg
Coca Cola (12 oz) 46 mg
Decaffeinated coffee (instant, 5 oz) 1 – 5 mg
Pepsi (12 oz) 38 mg
Espresso (1 oz) 30 – 50 mg
Milk chocolate (1 oz) 1 – 15 mg – milk chocolate has around 50% caffeine content of plain chocolate
Source: US Food and Drug Administration and National Soft Drink Association

Brodies have a retail shop where you can buy deliciously fresh coffee and tea as well as a range of mouth watering confections.

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