Let’s Talk About Tea:


This week, I was talking to one of my colleagues and going off on a tangent we began discussing tea. His parents are from UK. Today’s post is inspired by that conversation.

Milk First or Tea First:

The question of whether to add milk first or tea first is an interesting one. As part of writing this post, I did some research on this one. The first documented account of milk being added to tea is from Johan Nieuhof (1618-1672), a steward of the then Dutch ambassador to China. He wrote about adding one fourth of warm milk to tea with salt. The idea of using milk with tea was made popular in Europe by social critic Marie de Rabutin Chantal, the Marquise de Seven in 1680.

The socially correct protocol, according to Douglas Adams (author of Hitchhiker’s Guide to the Galaxy) and many others is to add milk in after tea. There are many anecdotes on why this is the case. The most popular version is about the quality of tea cups back in the day. Pouring hot tea first broke the low quality cups. The upper class of the society showed off their high quality cups by pouring hot tea first and then milk. The people who could not afford high quality tea cups poured milk first and then tea. Another reason could be also the way the process of making tea was documented. As noted above, the documented process was to add milk to tea.

George Orwell even wrote an essay on making tea called “A Nice Cup of Tea”. His preference was to add tea first and then milk. His logic was as follows;

One should pour tea into the cup first. This is one of the most controversial points of all; indeed in every family in Britain there are probably two schools of thought on the subject. The milk-first school can bring forward some fairly strong arguments, but I maintain that my own argument is unanswerable. This is that, by putting the tea in first and stirring as one pours, one can exactly regulate the amount of milk whereas one is liable to put in too much milk if one does it the other way round.

Douglas Adams on the other hand liked to add milk first even though it was not the socially correct protocol. Today, scientists will tell you that the proper way of making tea is to add the milk first and then tea. Milk proteins when exposed to a temperature above 75 degrees C (167 degrees F) will start to degrade through the process of denaturation. This is more prone to happen when milk is added to tea rather than when tea is added to milk.

The Lady Tasting Tea:

The story of the lady tasting tea is perhaps the most fantastic story in the field of statistics. There are a few different versions as to where the incident took place. The story goes that in an English afternoon in 1920’s, a statistician, a chemist and an algologist were sitting together. The statistician offered to make tea, and proceeded to pour tea and then milk. The algologist, a lady (hence the name a lady tasting tea) objected to the process. She told the statistician that she preferred to have the milk poured before tea. She claimed that she could tell the difference. The chemist who was the fiancée of the algologist immediately wanted to test her claim, as any warm blooded scientist would do. The statistician proceeded to create an impromptu test for the lady. He created four cups of tea with milk first, and then four cups of tea with tea first. He randomized the cups using a published collection of random sampling numbers. The lady was informed of the test protocol and then she tasted each cup and identified all the cups accurately, thus standing by her claim.

The statistician was Sir Ronald Fisher, the chemist was Dr. William A Roach and the lady algologist was Dr. Blanche Muriel Bristol. The story was documented by Sir Fisher in the groundbreaking book “The Design of Experiments” and in his paper “The Mathematics of a Lady Tasting Tea”. The probability of the lady getting all the results correct was 1/70 = 0.014. This value is less than the magical 0.05. Interestingly, Sir Fisher wrote the following about the 0.05 value in the paper;

“It is usual and convenient for experimenters to take 5 percent, as a standard level of significance…”

If the lady had gotten one result incorrect, the p-value would had been 0.243, and the testers would have failed to reject the null hypothesis that the lady has no ability to tell the difference between the two styles of making tea. Thus, one can say the test is not fair since if the lady failed once, it would not help justify her claim. In the paper, Sir Fisher advised that to improve the test, one should use 6 cups each of tea. The p-value of getting one incorrect is only 0.04, which is still less than 0.05. Thus, the lady has a little more leeway.

This story helped explain the idea of randomization and significance testing. The test’s efficacy is improved further if the total number of particular styles were kept secret. Dr. Bristol was told about the exact number of each style of tea beforehand.

The Answer to the Ultimate Question of Life, the Universe, and Everything:

In Hitchhiker’s Guide to Galaxy, the answer to the Ultimate Question of life, the universe and everything is given as 42! I came across a possible explanation during my research for this post based on Douglas Adam’s passion for tea.

42 = fortytwo

For tea two.

Two for tea!

Always keep on learning…

In case you missed it, my last post was about Respect for Humanity.