Brewing Assam means three things done plainly: boiling water, a measured dose of leaf, and a few minutes left alone. Assam is a black tea, fully oxidised, made from the large-leaf Camellia sinensis var. assamica, the broad-leaved variety, whose accepted name rests on the basionym Thea viridis var. assamica (the often-cited Thea assamica was never validly published). It is built for heat and made to be strong, so it forgives more than a green or a white tea does. Get the three measures right and a bad cup is hard to make. This is the Authority's standing method, and the reference for every part of it: the water, the leaf, the time, milk, the second steep, the difference CTC and orthodox make, and the test for a cup that is properly brisk.

The short method

For one cup, by weight and measure:

1. Boil fresh water to a full rolling boil, 100 degrees Celsius, 212 Fahrenheit.
2. Measure one teaspoon of leaf per cup, about 2 to 3 grams per 240 millilitres. A little more for CTC granules, which pack denser.
3. Pour the water on the leaf the moment it boils.
4. Steep 3 to 5 minutes. Three for brisk and bright, five for dark and milk-ready.
5. Strain off all the leaf. Add milk if you take it.

Everything below is the same method, documented part by part.

Water and heat

Use fully boiling water: 100 degrees Celsius, 212 Fahrenheit. Assam is not a green tea that scorches at the boil. It is a black tea, and the malt, the body, and the deep coppery colour only come out under full heat. Cooler water leaves them in the leaf and gives you a thin, pale cup.

Boil fresh water and pour it the moment it rolls. Tea wisdom holds that water reboiled or left standing off the boil sheds its dissolved air and pours a flatter cup; brew it fresh and you will not have to find out the hard way. The international tasting standard, ISO 3103, requires a fresh, full boil for every certified test, and it flags the water itself: hardness affects the flavour and appearance of the liquor. Soft water suits Assam; very hard water can mute the briskness and throw a dull scum on the surface.

Leaf and dose

Measure roughly one teaspoon of leaf per cup, about 2 to 3 grams per 240 millilitres. The laboratory tasting standard sets it tighter still, 2 grams of leaf per 100 millilitres of water, which is a stronger dose than most people pour at home and a good guide to how much leaf a serious cup wants.

The dose changes with the cut of the leaf:

• CTC (crush, tear, curl) is processed into small dense granules. They pack tighter in the spoon, so a level teaspoon of CTC is more leaf by weight than a teaspoon of whole leaf. Use a little more if anything, not less.
• Orthodox is whole or broken leaf, lighter and bulkier in the spoon. A teaspoon goes in loosely.

Strength comes from the weight of leaf, not from longer time. To make a cup stronger, add leaf before you add minutes. Over-steeping to chase strength only pulls bitter tannin and leaves the brisk character behind.

Time

Steep 3 to 5 minutes. The range is real, and it is yours to set:

• Three minutes gives a brisk, bright cup, lighter in the body, good without milk.
• Five minutes gives a darker, fuller, milk-ready brew.

The cut sets where in the range you land. CTC gives up its strength fast and is ready at the short end, 3 to 4 minutes; longer mostly adds bitterness. Orthodox leaf releases more slowly and rewards the longer steep, 4 to 5 minutes. For reference, the ISO 3103 tasting standard fixes six minutes for black tea, longer than a drinking cup wants, because a tasting brew is deliberately pushed to show every fault.

Strain off all the leaf when the time is up. Leaf left sitting in the pot keeps brewing and turns the next cup harsh. Taste as you go the first few times and you will soon know your own measure.

Milk, and the order of it

Assam is one of the few teas that genuinely improves with milk, which is why it anchors nearly every breakfast blend. Its body and tannin stand up to the jug where a lighter tea would simply vanish into it. The chemistry is plain: milk's casein proteins bind the tea's astringent tannins and soften the pucker, leaving the malt and the body intact.

Whether milk goes in first or last is the oldest argument in tea, and there is some science under it. The Royal Society of Chemistry, in its 2003 note on making a cup of tea, came down for milk first: pour hot tea onto cold milk and the milk's proteins denature, which begins above about 75 degrees Celsius, in uneven droplets and can throw a faint cooked off-flavour, while pouring tea onto milk already in the cup keeps the mix below that line. The effect is small, and the Authority declines to legislate it. Add a splash, stir, and judge the result, not the procedure. Sugar is your business; a strong Assam carries it well. The fuller account of milk, the chemistry, and chai is the spoke linked below.

A second steep

Good orthodox Assam will give a worthy second steep. Pour off the first cup, leave the wet leaf in the pot, and brew again, adding a minute or so to the time because the leaf has already given up its quickest strength. The second cup is lighter and often a touch smoother.

CTC is a one-pour tea by design. It is built to spend its strength fast and in full on the first brew, which is exactly what a brisk morning asks of it. A second steep of CTC is thin and not worth the wait.

CTC and orthodox: brewing each

The two ways Assam is processed brew differently, and it is worth keeping them straight at the pot. The fuller treatment of how they are made and when to reach for each is the spoke linked below; here is what each asks of the brew.

• CTC brews fast and strong: more leaf by spoon, the short end of the time, one pour, boiling water. It is the granule behind most tea bags, builders' tea, and the rolling boil of masala chai, where it is simmered in milk and water together.
• Orthodox brews slower and rewards patience: the long end of the time, a second steep, boiling water still. The whole leaf gives a more nuanced cup, and the better orthodox grades carry golden tip and a clearer malt.

The certified test

The Authority's standard for a finished cup is simple, and it is the same for CTC and orthodox:

• Colour: deep coppery red, not pale brown.
• First sip: brisk, lively, clean on the tongue, not flat.
• Through milk: strong enough to taste plainly with milk added, not washed out by it.

If you can read newsprint through the cup, it is underbrewed. Add leaf, add a little time, and try again. A cup you cannot taste through milk has not yet earned the name.