One shot or two?

In theory, an espresso has less, not more, caffeine than a brewed or filtered coffee, mainly because an espresso comes in a smaller serving. While an espresso "shot" is only 30ml, which you down in one go, a regular cup of brewed coffee is a long drink giving you at least 140ml. The result is that while you get around 60-80mg of caffeine in an espresso, the brewed coffee will provide more like 106-164mg. If you have a cappuccino or a latte made with one shot of espresso (which is how coffee shops make them) then these too should contain about 60-80mg of caffeine. This is less than a strong cup of instant coffee, which has up to 120mg. All of this said, the amount of caffeine in an espresso shot depends on lots of things, such as how much pressure is used to pass the water through the ground coffee beans and, not least, the type of coffee bean used. For instance, the robusta bean appears to have almost twice as much caffeine as the arabica bean. A lot of supermarket blends use low-grade robusta beans in their espressos, whereas brands such as Illy use only the more expensive arabica beans. If you are searching for the lowest caffeine espresso on the high street, then chains such as Starbucks and Caffè Nero use arabica blends. They tend to advertise the fact quite clearly since it is a mark of quality. If you are attempting not to overdo caffeine throughout the day, then the best advice is to try to have no more than four "normal size" caffeine-containing drinks. These include any type of coffee, tea (including green tea), cola, most energy drinks and many cold remedies. Switching to decaffeinated coffee is another way of limiting intake. Decaffeinated coffee (and tea) should have no more than 0.3 per cent caffeine, which works out at around 3mg of caffeine per small (150ml) cup and so going "decaff " will see caffeine intakes plummet. There are three ways of removing caffeine from the coffee bean. One involves the use of hot water and charcoal filtration, another the use of pressurised carbon dioxide (used by the Café Hag brand) and the third is by the use of a chemical solvent such as methylene chloride, which is the most common. Such chemicals bind with caffeine, and both the chemical and the caffeine are then removed, leaving the bulk of the flavour intact. It is probably the last method that you are concerned about. I have heard of health scares associated with the idea that residues of these chemicals remain in the coffee and may trigger cancer. Residues of such chemicals are well within safety limits of five parts per million and in many cases are at such low levels that they are undetectable. To put this into perspective, the US Food and Drug Administration said in 1985 that if residues were double this, at 10 parts per million, they would cause less than one case of cancer per million people drinking six cups of decaffeinated coffee a day for 70 years.