Brewing Rooibos

Brewing rooibos is the act of steeping the dried, oxidised leaf of Aspalathus linearis, the red bush of the Cederberg, in hot water to make a deep amber-red infusion. The whole method fits in one line: one heaped teaspoon of rooibos to a cup, water at a full boil, a steep of five to ten minutes, and drink. The standing rule of tea, never over-steep, is a rule about tannins, and rooibos is low in them.

The standard method

You will see filtered or soft water recommended for tea generally, on the grounds that minerals in hard water bind to a tea's polyphenols and dull the cup. That advice was written for Camellia sinensis. When the mechanism behind it was tested directly on rooibos it did not hold: the mineral film hard water forms on black and green tea never forms on the red bush at any hardness, so for a cup you mean to drink today, plain tap water is very unlikely to be the problem. Warming the pot or cup first keeps the water from dropping below temperature on contact, which matters less for rooibos than for delicate teas but does no harm.

Almost every rule a tea drinker already knows is a rule about Camellia sinensis, and most of them simply do not carry over:

Use boiling water

Green tea takes water well off the boil, white tea cooler still, and a too-hot pour will scorch a delicate leaf into bitterness. None of that applies to red rooibos. It is a hardy, needle-fine shrub from the Cederberg, and the red kind has already been oxidised to a deep red-brown before it ever reaches the cup. Water at a full boil is the standard pour, and it is what the SA Rooibos Council recommends. Slightly cooler water, around ninety degrees (194°F), will still make a fine cup, so a kettle a minute off the boil is no failure.

Why it never turns bitter

The bitterness and the dry, mouth-puckering astringency you can pull from an over-steeped cup of black or green tea come mostly from tannins, the polyphenols that Camellia sinensis carries in quantity and that go on leaching into the water the longer and hotter it steeps. Tannins bind to the proteins in saliva, which is the source of that puckering dryness on the tongue, and they grow more dominant the longer the leaf sits, which is why ordinary tea is brewed against a clock.

How long to steep

Steeping is the one dial worth setting to taste.

• Three to five minutes makes a light, clear cup, the colour a clear red.
• Five to ten minutes is the standard: a full, rounded cup, the colour deepening toward mahogany and the woody, honeyed sweetness coming forward. South African reporting on the science⁸ lands on the same ten minutes at a full boil as the mark of a "perfect" cup.
• Ten to fifteen minutes does not turn it bitter. A forgotten pot comes back strong but not spoiled.

Milk, honey, and the red latte

• Milk turns it into a soft red latte.
• Honey or sugar suit its natural sweetness, though many drinkers find a long steep sweet enough on its own.
• Lemon brightens it without the bitterness that can sharpen a tannic black tea cut the same way.

Brewing green rooibos

• Water slightly off the boil, around eighty-five to ninety degrees (185 to 194°F), suits it better than a hard full boil.
• Steep a touch shorter, four to six minutes, to keep the grassy, delicate character.
• Drink it fresh, as Carmién Tea⁵ advises especially for the green kind.

The limits

A pot boiled hard and reboiled can turn flat, the brightness cooked out of it. Low in tannins is not the same as free of them, so a faint astringency at the far end of a very long steep is possible, just never the harsh bitterness of true tea.