CREST Bronze Award – typically 10 hours of project work

Food & Drink: Tea CREST Awards project
CREST Bronze Award – typically 10 hours of project work
Make the perfect cup of tea
Most people know how to make a cup of tea. But not everyone makes it exactly the same
way. In this project you can carry out some experiments to work out how to make the
perfect cup of tea for you. Then you‟ll write a standard procedure (a set of really detailed
instructions) so that other people can make tea just how you like it.
There are lots of things to think about when making a cup of tea. These include:
How much water should you use, and how hot should it be?
How much tea should you use?
Will you use tea bags, or loose tea?
How much milk will you use, and will you put it in before or after the water?
What sort of milk will you use: full fat, semi-skimmed or skimmed?
How long should you leave the tea bag (or tea leaves) in the cup?
Do you want sugar? How much?
Setting up some experiments
Any results will depend on your own personal taste. But you can still carry out some fair
tests to decide how best you like your tea. All the things listed above are variables. If you
keep them all the same, but change one, you can work out what you prefer. For
example:
Make three cups of tea keeping all these things the same:
the amount of water
the type and amount of milk (and whether you put it in before or after the water)
the same number and type of tea bag (and the length of time you leave it in the cup)
Use three different temperatures of water (for example, one cup with 50 o C, one with 75
o
C and one with 100 o C). By tasting each cup you can decide which temperature of
water to use for your perfect cup of tea. Do lots more experiments, but keep different
variables the same, and change others. After each experiment you should write down
your preference.
Instructions on how to make the perfect cuppa
Now you‟ve decided on all your personal variables you can write a standard procedure.
This is a set of really detailed instructions (a bit like a recipe) so people can make tea
exactly how you want them to.
For further information visit our website www.britishscienceassociation.org/crest

Food & Drink: Tea CREST Awards project
CREST Silver Award – typically 30 hours of project work
Design and make a quick-brew tea bag
Start by having a look round the shops at all the different types of tea bags that are
available. Have a look at the range of different shapes and sizes. Carry out some research
into how tea bags are made – perhaps you could contact a tea bag manufacturer for
some help. They may also be able to tell you how their tea bags are tested in industry.
Research what happens between when tea leaves are picked, and when tea bags land
on our supermarket shelves. Find out if there are different processes for different types of
tea.
Designing your bag
Decide how much tea should be in each bag. You could do this by taking the tea from a
variety of tea bags and working out the average volume of tea.
The material
You need to think about what properties the material should have. You may want to
design some tests to check the materials‟ suitability. For example:
you need something porous so the tea will dissipate through the water (you could try
to actually measure porosity)
it shouldn‟t disintegrate or break easily when wet
it should be non-toxic
A couple of suitable examples are muslin and cotton.
You will also have to think about how you will cut and join your materials. You may want
to design some tests to check your joining methods work.
The tea tests
When you‟ve picked a range of suitable materials, you need to check which one provides
the quickest brew. There are lots of things to consider (it has to be a fair test). For example:
Make sure you make the tea bags the same size and shape (a simple design will be
best at this stage – you don‟t want to go sewing fancy shaped-designs when you‟re
just checking the material!)
Make sure you use the same amount and temperature of water
Decide whether or not you will stir the tea
How you will decide when the tea has brewed (for example, will you wait until it turns a
certain colour)?
Make sure you use the same type and amount of tea leaf in each tea bag (you could
buy a packet of loose tea to make sure you‟re using the same type each time)
The shape
The range of shapes you test is up to you. You could test the already-available types
(square, round, pyramid, for example) or you could make totally new designs.
Think about the size of the tea bag; should it be large, so the tea moves around freely
inside, or should it be small, so the tea is packed tightly within?
When you‟ve designed a few bag shapes (about five should be enough), make the tea
bags using your chosen material. Then carry out the same tests as when you were testing
the materials.
The tea bag
Combine your results and you should have the perfect quick brew tea bag!
For further information visit our website www.britishscienceassociation.org/crest

Food & Drink: Tea CREST Awards project
CREST Gold Award – typically 70+ hours of project work
Investigate tannin, caffeine, fluoride and flavanoid in tea
You‟re going to produce a leaflet entitled: “Everything looks brighter after a cup of tea –
Fact or Fiction”. It will explain all the health risks and benefits of drinking tea. You will
substantiate any of your claims by investigating tannin, caffeine and flavanoids. You will
carry out analytical tests on tea samples. Your leaflet should be able to list a number of
different types and brands of tea with the findings from any tests explained.
Tannin content
Start by looking at the range of teas available. Pick a wide selection of types to test. First,
you need to do some research to find out what tannin is. Find out what it does to your cup
of tea – both in appearance and flavour. Find out if it has any other uses. Does it have any
harmful/beneficial effects on health? Find out if any teas give information about their
tannin levels on the packaging. Design a test to determine which of your tea samples
contains the most tannin. When you‟ve got some rough, comparative results, find out how
to determine actual quantities of tannin in tea samples. You will need to investigate
protein precipitation and spectroscopy. When you‟re au fait with the method you should
set about determining the tannin levels in your tea samples. You may need to link up with
a university or someone from industry if your school/college doesn‟t have the appropriate
equipment.
Caffeine content
Next up is caffeine. There‟s a lot of literature available about why too much caffeine is
bad for us. Conduct your own research and collate your findings. Try also to find out if
caffeine is beneficial in any way. Find out if any teas give information about their caffeine
levels on the packaging. Pick decaffeinated as well as caffeinated teas to test.
Design some tests to see if drinking caffeine can affect performance. Note: only conduct
these tests if you have written permission from the subjects. Work out if it‟s possible to
determine the caffeine levels in your tea samples. You will need to find out about High
Performance Liquid Chromatography (HPLC). You could also determine the caffeine
levels in a variety of coffees. Which contains more caffeine, tea or coffee? Note: you will
almost certainly need to link up with a university or someone from industry to use HPLCequipment.
Flavanoid and fluoride content
Tea contains flavanoid, a type of polyphenol. Find out about the health benefits of
flavanoids. Find out if any teas give information about the number/amount of flavanoids
on the packaging. It is possible to determine the polyphenol content of your tea samples.
However, you won‟t be able to conduct such tests in your school/college (or even a
university); stick to researching the methods. Polyphenols are extracted using 70%
methanol/water solvent. The content is determined by a method called „Folin Ciocalteu
spectrophotometry against gallic acid standards‟. Tea also contains fluoride. Find out the
health benefits/risks of fluoride. Find out if any teas give information about the amount of
fluoride on the packaging. As with flavanoids, determining the content of fluorides won‟t
be possible within a school/college. Again, research the methods and, if possible, contact
someone in industry to demonstrate them.
For further information visit our website www.britishscienceassociation.org/crest

Food & Drink: Tea CREST Awards project
Health & Safety considerations
When you carry out experiments make sure you:
(a) find out if any of the substances used or made, or any of the equipment or procedures
are hazardous
(b) carry out a risk assessment (in other words, think about what could go wrong and how
serious it might be)
(c) decide what steps you need to take, if any, to reduce the risks. For example, by
wearing personal protective equipment, being aware of how to deal with any
emergencies and so on
(d) make sure your teacher checks your plans and risk assessment before practical work
starts
(e) if special tools or machines are needed, these should be used in a properly supervised
workshop or D&T room.
NOTE: Your teacher will check your risk assessment against that of his/her employer (i.e.
your school or LEA). If no risk assessment exists for your activity, your teacher may need to
obtain a special risk assessment (e.g. by contacting the CLEAPPS School Science Service.)
This may take some time.
For further information visit our website www.britishscienceassociation.org/crest