Don't strike me down for it, but one some days, I find myself getting a hot Americano in the morning, and using hot water to reheat (and effectively, water it down) throughout the day if I don't drink it quickly. Sure, it doesn't taste as great as it did when it was full flavor, but at that point I'm seeking two things: warmth and caffeine. One thing @caricakes and I noticed while talking about this (she does it as well!) was that we were getting more energy throughout the day because of this method, to the point of even feeling uncomfortable at times because of the prolonged caffeine intake. Still, it seemed a bit strange because in the long run, it was the same amount of caffeine entering out bodies. So, why does this happen? Well, it all has to do with how caffeine affects your body, and then what factors affect how long caffeine stays active in your body. The basics biology of your body: Your body produces a neurochemical called adenosine throughout the day that then passes through receptors that measure it's levels. The higher the level, the sleepier you feel (yes, I am simplifying this). Your body's biology on coffee: Caffeine is the same shape and size as adenosine, so the receptors can't tell the difference: caffeine attaches to the A1 receptor instead of adenosine, and then the receptor cannot track the levels of adenosine being produced. So, you don't feel tired. As caffeine blocks the door, dopamine and glutamine (let's call them the 'party' molecules) swell, giving you a burst of energy. But, when the caffeine finally releases, your body processes the adenosine in a rush, making you feel groggier than when you started. So how about that watered down Americano? Ok, now that the coffee basics are covered, here's the answer: caffeine has a half-life of about 4-6 hours. This means that half of the amount of caffeine in your system exits every 4-6 hours. So, because of this, when you drink a cup of coffee more slowly, the effects are smaller at first, but last for a much longer time because the amount is being increased by drinking, not only decreased by excretion. Make sense? Pretty simple, once you think about it: drink the coffee slower it's effects last longer (even if they're smaller!)
The Science of My Americanos
I start my day with a mug of Americano. I brew it around 5:30 AM ( I am usually out of bed around 5 AM), and drink it slowly for about an hour or so. I never thought about adding hot water. An hour of a cup of coffee always seemed to me long enough...