Uncertain-tea?

James Vines

In Britain, 165 million cups of tea are consumed every single day, with English Breakfast tea being the most common. The matter of a perfect cup of tea is a highly contentious topic. There are so many variables. Do you add sugar? What’s the perfect amount of milk? And maybe the most contentious of them all, how long do you brew for?

98% of us take our tea with milk, but one of the first to scientifically investigate the effects of adding milk to tea was statistician Ronald A. Fisher in 1935, who was interested in the effects of adding milk before or after the water. His study was only conducted upon one participant, Muriel Bristol, who claimed she could taste the difference. While the finer intricacies of Fishers experiments were really concerned with statistical probabilities, he also concluded that Bristol could, most probably, tell the difference between the two different types of tea.

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There are many arguments both for and against pouring the milk in first. Tradition dictates that milk is added first. One theory for this concerns the delicate nature of early teacups, which were prone to cracking under a sudden influx of recently-boiled water. Another theory suggests that milk which is creamy or warm may rise to the surface of a cup of tea as globules of fat. This was also thought to kill bacteria by boiling them, which may be lurking in questionable milk.

While these arguments all seem reasonable, in 1946, George Orwell argued “by putting the tea in first and then stirring as one pours, one can exactly regulate the amount of milk, whereas one is liable to put in too much milk the other way round”. In 2008, the Royal Society of Chemistry also got involved suggesting that adding milk second could ‘cook’ the milk, giving it a boiled taste due to greater denaturing of the proteins. Whether this ‘boiled’ taste is preferable however, was not mentioned. Of course it is important to mention, that the above only concerns tea poured from a pot; milk must be added second if brewing in the cup, or else the tea bag will not reach a hot enough temperature to infuse properly.

Another hot topic in the tea drinking debate is whether to add sugar. 41% of tea drinkers take sugar; as a result the issue of sugar is somewhat down to personal preference. For certain however, sugar should be added in the cup, and only once the tea bag has been removed. This prevents any sugar getting caught up and wasted inside the tea bag.

A less contentious area is the question of loose tea versus tea bags;  most tea lovers will agree that loose tea leaves make for a better brew. The tea in teabags is normally made from the “dust and fannings” from broken tea leaves, rather than the leaves themselves. This affects the quality of the tea. Finely broken leaves loose their oils and aroma, resulting in a more bitter taste. While tea bags are somewhat inferior, their cost and convenience make them more desirable for millions of us, with loose tea making up just 1% of all tea purchases.

It is almost without question among tea connoisseurs, tea should be made in the pot, not in the cup, but how long should you brew for? Studies from 1981, by Prof. Michael Spiro showed tea needs to brew in the pot for a minimum of 2 minutes. However even after 2 minutes, only 64% of caffeine has been removed from the leaves. In fact, it will take a whole 15 minutes of brewing to remove 100% of the caffeine. Further studies by Hicks et al. in 1996 shows it’s even worse for tea bags, with only 33% of caffeine being removed after 2 minutes. It is worth noting, caffeine levels vary naturally in types of tea and levels in one type may overlap with another type. All the types of tea are produced from the leaves of the Camellia sinensis plant, including including white, green and black teas. It is the differing processing methods which result in variations in tea type.
To conclude, there doesn’t seem to be a clear consensus on how to make the perfect cup of tea. There’s certainly areas where a cup of tea can be unquestioningly improved, such as by using tea leaves instead of a tea bag, but other areas are down to personal preference, such as whether to put milk or water in first, or whether to use sugar. But, however you take your tea, don’t take it from me, it’s mine.

The Science of Predicting Elections

James Vines

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Image Credit: Wikimedia Commons

The study of elections is known as psephology, or the study of ballots. Psephology is not a science of experimentation, but of observation. Its purpose is to predict the outcome of an election, and to use these predictions to influence the actual outcomes. When carried out correctly, psephology abides by strict rules of sample size and random selection to reliably assess an election’s outcome.  

In its most basic sense, psephology is used to inform both the media and electorate about the likely future outcome. Ideally, this would be achieved by asking every member of the electorate for their vote. However, in a country the size of America, where 218 million individuals are eligible to vote, this just isn’t feasible. Thus pollsters, the people who conduct the polls to be analysed, need to use a sample.

Pollsters need to select a scientifically representative sample. This means that if 50% of your population is female, then 50% of your sample needs to be female. Selection needs to be considered for as many different demographics (a section of a population) as possible: race, religion, age, location, income, etc.

However, directly selecting individuals who match your demographics would not be random. Randomness is very important in psephology, with pollsters utilising a branch of mathematics known as Probability Theory. The basis of Probability Theory is the idea that everyone in a population has an equal chance of being included in a sample. In practice, this means using random digit dialling machines which dial phone numbers completely randomly. Pollsters apply two mathematical laws: ‘The Law of Large Numbers’ and the ‘Central Limit Theorem’. These laws allow for generally accurate predictions of electoral results.

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The Law of Large Numbers expresses the idea that as the number of trials of a random process increases, the percentage difference between the expected and actual values goes to zero. In the context of polling this means that the more totally random people we ask the more likely the results are going to follow the actual trend – rather than following a trend we have observed through chance.

An example of this would be rolling a fair 6-sided die. If the die was rolled 6 times and it rolled a 5 every time we might conclude that the die always rolls a 5. Of course, this would be wrong as the probability of getting any result on a fair die is one sixth. We got a 5 every time we rolled it through pure chance, if we rolled the die 6,000 times this kind of chance would even out. We would observe the die to roll each number around 1,000 times. From this we would conclude that the die does indeed have a probability of one sixth for rolling any result.  Thus, the more repeats we do the closer the result we observe becomes to the actual result.   

The Central Limit Theorem is similar, it states all of the samples will follow an approximate normal distribution pattern, with all variances being approximately equal to the variance of the population divided by each sample’s size. In the contexts of polling this means that in a large enough, random sample, results will fall within the limits of a normal distribution curve (or a bell curve), moreover this normal distribution still applies if scaled up from a smaller sample to a larger population – and that’s exactly what we’re trying to achieve!

Using the Law of Large Numbers and the Central Limit Theorem together is what allows pollsters to transfer their findings from a sample to the larger population. The Law of Large Numbers means that the chance of ‘rouge results’ are evened out and the Central Limit Theorem means we can apply a small sample to a bigger population and the trend will be the same.

Pollsters have to weight each of the responses to reflect the representativeness in the whole population as mentioned earlier. This is really important as not everyone who is eligible to vote in a population will vote. If older people are most a country’s electorate, their responses will be weighted higher than the responses younger people. This ensures the sample taken is representative of the actual voting population.

Despite pollster’s best efforts, polls are never perfect. Primarily, this is because a truly random sample can never be achieved –  some demographics may not own phones or be less likely to agree to take part in a poll. There is also the issue of ‘shy’ voters, who may not admit to the candidate they will really vote for, or who may not actually vote at all.

These kinds of problems can throw pollsters off if they don’t equate for them in their algorithms. One example is the final 1992 UK General Election polls, which put the Conservatives at 38% of the vote, indicating a hung parliament. The actual results of the election saw the Conservatives with 42% of the vote and a 21-seat majority. This incorrect prediction was put down to Conservative supporters not disclosing their voting intentions. Today pollsters in the UK account for the ‘shy tory’ vote by asking their sample how they previously voted, and then assuming that some would vote that way again, but at a reduced rate.

Polling is a difficult process, but it is essential to enable an electorate to assess how a political party is fairing. It is also important for the candidates themselves; they use polls to inform much of their behaviour, appearance and policies. For a candidate to win it is essential for them to satisfy the largest demographics of voters. This aim is only achieved through decision making based around how pollsters predict the largest voting demographics will respond to certain policies. Thus, it makes sense for a candidate to focus their efforts gaining the votes of the largest voting groups.  This means policy often revolves around the largest voting demographics as opposed to groups who are unlikely to vote and so these groups will often end up being overlooked.

Chocolate Crisis!

James Vines

According to a headline in the Daily Mail earlier this year, “THE WORLD IS RUNNING OUT OF CHOCOLATE”. To me that sounds pretty worrying – I wouldn’t want to see a world without chocolate. But what is it we’re running out of? Why is it so important? And what solutions are there?

Seattle: Theo Chocolate Factory Tour

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What Is It We’re Running Out Of?

If you ever took a visit to Cadbury World in Bournville when you were younger, you’ll probably remember being shocked at the fact chocolate is made from beans. Beans grow on trees, fruit also grows on trees, fruit is healthy, so chocolate must be healthy too, right? That has always been my justification as to why chocolate must be good for you.

The actual process of turning cocoa beans into chocolate was lost on me when I was younger, however it turns out beans are pretty important when it comes to making that chocolatey goodness. It’s these beans that we’re running out of.

Cocoa beans are grown year round in countries like the Ivory Coast, before they can be harvested. The beans are split in two and harvested for their pods and pulp, which are then fermented in barrels for up to 7 days. Fermentation allows the chocolate flavour to develop and is a key part of getting that signature rich taste.

Following fermentation, the beans are dried, bagged, and sent to the chocolate factory to be roasted. The time and temperature of roasting is often kept secret, and is unique to each chocolate maker. Once roasted, the beans have their crispy shells removed before being ground. Grinding turns the beans into a pure form of chocolate which contains cocoa solids and cocoa butter. Some manufactures will remove the cocoa butter and replace it with cheaper vegetable fats. This is because cocoa butter is used in greater quantities in more premium chocolate bars to give a smoother texture and glossier appearance.

Further refining then occurs in a conching machine; this is also where the milk powder, sugar and other flavours are added. Deciding how long to conch for has the biggest impact upon the chocolates taste and texture –  it will vary depending on the maker’s skill and preference. The final step is to temper the chocolate, giving it that distinctive ‘snap.’

The whole process of chocolate production is thus, unfortunately, reliant on cocoa beans.

Why Beans?

You might be wondering if we can ‘fake’ chocolate, that is, make it without the beans. Well, making fake chocolate is harder than it sounds. The taste of chocolate combines over 400 different flavour compounds, and getting the right balance of all of these is pretty hard to replicate.  Also, without cocoa butter from the beans chocolate loses its “melt in the mouth” property. As we’ve seen, cocoa butter can be replaced with vegetable fats, but this technique often leads to a lower quality form of chocolate and is tightly controlled by EU regulations – take out too much cocoa butter and your chocolate is no longer allowed to be classed as chocolate. You are allowed to take out the cocoa solids however; this makes white chocolate!

Who Says We’re Running Out? Just Grow Some More!

I bet you didn’t know that the International Cocoa Organisation based in London is responsible for monitoring the world’s cocoa needs. They take the business of cocoa beans very seriously. Their job is to keep a constant track of the availability and price of cocoa beans throughout the year.

As of the end of trading on October 12th this year they put the price of cocoa at $2651.01 per tonne! The price of cocoa is affected by estimates of production and by weather conditions in the cocoa mega-producing countries like Ghana, Nigeria and Cameroon, which collectively produce over 1.5million tonnes of cocoa every year. That’s nothing though compared to the Ivory Coast which, alone, is responsible for the production of over 1.6million tonnes of cocoa a year. It is only these tropical countries that are capable of cultivating the cocoa plant, and getting them to produce more is not always easy.

That sounds like a lot of cocoa, so where is it all going? Well, the EU is the world’s biggest importer of cocoa, taking in 53.24% of all cocoa imports. The International Cocoa Organisation published their latest quarterly bulletin in May 2016. Their forecast predicts that by the end of this ‘cocoa year’, the total world production of cocoa beans will be 4,039,000 tonnes of beans. However, consumption will be at 4,179,000 thousand beans; that leaves a deficit of 180,000 tonnes of beans in just one year! Luckily for us, the clever cocoa people know we have 1,432,000 tonnes of beans sitting in storage somewhere. In other words, we still have quite a few beans in our bank account, which is a good job too, as I don’t know of any banks that lend out cocoa beans.

So while it’s true that we are consuming more cocoa beans than we are making, we’ve built up a nice reserve of beans. This means that headlines such as ‘THE WORLD IS RUNNING OUT OF CHOCOLATE’ shouldn’t be taken too seriously. Your favourite chocolates will still be hitting the shelves for some time yet.