A scientist's guide to life: How to make the perfect cup of tea

Make it in a mug…

… or a tea cup. Avoid disposable Styrofoam cups. They’re the worst. Styrofoam is porous so it will absorb some of the flavour compounds and affect the taste. If you’re on the go, opt for reusable cups made from inert materials like ceramic or glass. Plastics can absorb flavours over time, so will kill the flavour of what you’re drinking.

If you like your tea sweet, go for an orange mug.

There’s a huge amount of psychology involved in the way we perceive taste. For example, hot drinks taste sweeter if they’re in an orange or red mug, compared to if they’re in a blue or white mug. Similarly, if you were to drink from a fine bone china cup, you’d probably associate that with being special, and would be more likely to taste and appreciate the flavours.

Water quality is important.

Most of your tea is water, after all. If the water is too soft and doesn’t contain any minerals, the tea can taste soapy. If it’s too hard and contains a lot of minerals, such as calcium and magnesium ions, it can cause scum to form on the tea’s surface. This looks unsightly and can alter the flavour. If you live in an area with hard water, you can soften the water by filtering it.

Loose leaf gives more flavour than tea bags.

This is because the leaves have more space to move around and distribute their flavour. That said, well over 90 per cent of the tea drunk in this country comes from tea bags. Historically, this would have been of poorer quality because tea makers used to keep their best leaves for loose leaf tea. That’s not true now, and tea makers go to great lengths to ensure the quality of their tea bags.

Let it brew.

Most people let their tea brew for around two minutes, but five minutes is ideal. It’s too hot to drink before then anyway, and the extra time means your tea will have more flavour and antioxidants. Warning – if you leave the bag in for too long, you’ll also end up with more tannin molecules, which can make the tea taste bitter. When we did research as part of BBC Two’s Inside The Factory programme (look out for it on iPlayer), we found that the antioxidant levels were 13.9mg with a 30-second brew, but were more than double that after a five-minute brew.

Read more about tea:

• Should I squeeze my teabags?
• Diet rich in fruit, vegetables and tea linked to lower Alzheimer’s risk
• Is it possible to drink too much tea?

Milk or hot tea first?

If you’re making tea in a mug, add the milk after the tea, at the last possible moment before drinking, so the tea stays as hot as possible for as long as possible. Make sure you use freshly boiled water. All this will help the flavours to diffuse through the liquid.

Non-dairy milk is good.

Although you can’t call it ‘milk’ – it’s basically nut juice! I’m doing some research on this at the moment, but the take-home message is that oat milk tends to have a good flavour profile for mixing with teas and coffees.

• This interview first appeared in issue 355ofBBC Science Focus Magazine–find out how to subscribe here