I know it is unacceptable but I have not felt inspired over the busy summer holidays to write anything profound for the blog. With the term up and running smoothly now it really is time to put pen to paper. I want to write about meat from cloned cows, the Telegraph article about red wine being good for you or Stephen Hawking’s exciting new book. Instead, I find myself gripped in a caffeine induced frenzy to write about coffee. The inspiration for this is the fabulous new espresso machine that has appeared in the staff room. I don’t normally drink much coffee, but I do like a bit of shiny technology. As a result I have been heavily dosed with coffee this week.
A shot of espresso is made by forcing about 45 ml of hot water through tightly packed, finely ground espresso coffee. This is done at 15 times normal atmospheric pressure so that the water is in contact with the coffee for just 25 seconds. What should emerge is a dark brown, slightly thick liquid with a small quantity of crema (or dark foam) on top. The coffee has to be ground in the correct way, to the perfect coarseness and then packed with the ideal tightness. The water has to pass through it at just the right speed to pick up the aromatic compounds that impart flavour, without collecting too much of the bitterness.
The shot of espresso can then be used to make a range of drinks. Our machine does an Americano (one shot of espresso to two shots of hot water); a Latte (one shot of espresso to two measures of hot milk); a Cappuccino (one shot of espresso, one measure of hot milk, one measure of milk foam as insulation over the top).
The active ingredient in coffee is caffeine or trimethylxanthine which is a naturally occurring chemical in the leaves and fruits of many plants. It acts as a defence system, resisting attack by various species of insect. In humans it helps to prevent tiredness by blocking adenosine receptors in the brain and mimics the behaviour of dopamine which triggers the pleasure sensors in your brain. It is hard to tell from the popular press whether we should be worried about our coffee consumption. Today’s Mail Online has this article warning of the dangers of filter coffee which might surprise those who read this one last year that confidently asserted that coffee could reverse the effects of Alzheimers disease. I shall write again about caffeine and try to present the evidence as it is currently understood.
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