The question was formed recently due to a conversation with a fellow tea-drinker. Does tea in a large cup cool off quicker – or slower – than in a small cup? I thought previously that the greater area in the larger teacup would cause a quicker cool-off than the small area of a smaller teacup. However, the volume is also larger, so how does that effect the cool-off?

One possible alternative is to consider the growth of area versus volume. Since area grows by O(n^2), but volume grows by O(n^3), it might seem that the larger the container, the more energy that needs to irradiate through a smaller area. In general, this theory holds with for instance animals – mice needs to eat much more often than elephants, because they have a much larger skin surface compared to their volume. An elephant the size of a mouse would die – it would never be able to feed itself quickly enough the replace the heat loss through the skin.

So, the following experiment was set up. Hot water at a starting temperature of 96 C was poured into different containers:

• Cup A – a small, paper cup for holding “Glögg”. Diameter 6cm, 1x water content.
• Cup B – a large McDonalds coffee mug (official McD size: “medium”). Diameter 9cm, 2x water content.
• Cup C – a medium-size ceramic coffee mug. Diameter 8cm, 1.3x water content.
• Cup D – a large (=tall) glass. Diameter 7cm, 2x water content.

Sample data was collected over 15 minutes using a steak thermometer. (Not the world’s most precise, mind you.)

The results are as follows (time is in UTC):

Surprisingly, the container that held its best was the McDonalds coffee mug. The water in the McDonalds mug was consistently hotter than in the others.

Not surprisingly, the small paper Glögg cup was a total failure – dropping down below the measurable 55 degrees Celsius on the steak thermometer, and had to be estimated to about 52.

Unfortunately, it seems that the data collected so far fails to support any conclusive theory. It seems to be largely dependent on the materials of the container, as well as “other factors”, not determined by this study.

Chamomile tea is very good. I started drinking chamomile during a slight Chinese period of mine (it wasn’t anything as extensive as my military period). It’s a pity I don’t drink it more.

Tea holds the same properties over coffee, as cats do over dogs. It’s more subtle, quiet, distinguished. It doesn’t make a fuss, it’s got its own gentle character, and it bristles with class. Chamomile, while technically not a tea in itself – herbal teas are sometimes included among teas, sometimes not – exudes that same kind of distinguished charm.

There are two kinds of teas that go very well in a specific circumstance; and that’s when you sit on a balcony, or front porch, and watch the gentle summer rain. It’s warm, and there’s a quiet, sad tap-tap-tap on the roof from the rain drops, and a quiet splashing of the water trickling down the sides of the building and gently falling on the surroundings. And that’s when these two teas shine in all their glory. Number one, the chamomile; and number two, the lapsang souchong.

Chamomile has a rather sharp, distinct herbal taste, and it is countered very well by the smoky, heavy flavor of the lapsang. As both have a very organic feel to it – very earthy, natural somehow – they are, in my opinion, ideally suited for this kind of activity: To gently sit and watch the rain fall while you’re immersed in quiet thoughts about life.

I’m sure you’ve all read the funny tandem writing story where chamomile tea figures briefly.