London - Ethiopian goatherders are what I think whenever I walk past a Starbucks. Or at least, I have done since Wednesday.
It was then that I received How to Make Coffee: the Science behind the Bean by Lani Kingston (Ivy Press) and learnt that, in all likelihood, Starbucks owes its billions to an observant goatherder in the year AD1000 who noticed that his charges got a bit frisky when they ate coffee-plant leaves.
The book is a pocket-sized encyclopaedia, and having become an enthusiastic conscript into the legions of coffee bores, I find it hard to put it down.
The upside, though, is I have learnt such things as this: it was possible for a 15th century Turkish woman to divorce her husband if he did not provide her with sufficient coffee.
The book is especially interesting on the science of coffee, though. Like most people, I drink two to three cups of coffee a day, and do so mainly because it gives me a fillip in the long afternoon. The reason is that on a molecular level, coffee and human biochemistry are to some degree compatible. Caffeine – which stays in the body for four to six hours – is energising because of its interaction with adenosine receptors in the brain.
Adenosine is a biochemical by-product of all the neurons firing in our brains while we are conscious. The central nervous system constantly monitors the quantity of it in the body. When there is too much, the brain slows down neural activity and causes blood vessels to dilate, and this, in turn, makes us sleepy. Caffeine binds to your adenosine receptors. This prevents the brain from detecting levels and leads you to feel as energetic as the herder’s goat.
The thrust of the book comes at the end, on how to make coffee. There are tips for people who use a cafetière. The first thing to note is you must warm up the glass of the press before adding 7g of coffee per 100ml of water (a revelation to me). Never use boiling water – wait for 30 seconds to a minute. Then leave it with the lid on, but plunger up, for three minutes and 45 seconds and then skim off the grounds floating on the top, to avoid sediment. It is only now that you take the plunge with the plunger, and then serve immediately.
Try it yourself, you’ll never look at instant again.
The Independent