The mist hangs thickly over rolling hills covered with a green patchwork of thigh-high tea bushes. Workers wearing boots and aprons move methodically through the fields, choosing the youngest tips to throw into their sacks.

The dampness in the air and the light drizzle that fell last week was welcome, because there has been so little of it lately in Kenya, the leading tea exporter in the world.

Drought has decimated crops, including tea, and, as output has fallen, so prices have risen in accordance with the most basic rules of supply and demand. At a tea auction in August in Mombasa, where more than a third of world tea exports are valued, prices reached a record $3.97 (£2.45) a kilogram.

Changing climatic patterns always make rains less predictable, but in Kenya land grabbing and deforestation in the Mau Forest — one of the key water catchments — has made the problem worse.

The 400,000-hectare forest acts like a vast sponge, regulating water flow and moisture across a huge area and creating ideal conditions for growing tea on its western side.

Combined with failed rains across Kenya, the destruction of the forest has had a disastrous effect on tea yields, reducing worldwide supply.

“We have been months without rain in Kenya, so production is down, which is why prices are rocketing,” said John Maina, the production manager at the Mabroukie Factory in Limuru, which is owned by Unilever, the maker of PG Tips.

Brooke Bond built the factory in 1938 close to the spot where colonial settlers planted the first tea bushes more than a century ago.

Pacing through the factory, Mr Maina pointed to the near-empty withering troughs where fresh tea leaves are blow-dried for 16 hours to soften them for the cutting that releases bitter tannins.

In another vast room, finely chopped tea leaves, like piles of soil, lay fermenting in little skips but, again, most of the containers were empty. “In a good season we process 80 metric tonnes every day, but now it is only 40,” Mr Maina said.

It is not only the factories that are bare; the tea plantations themselves are eerily quiet.

Most tea in Kenya is grown by smallholders who draft in casual employees to pick the leaves but, with production down, the pickers are finding work scarce. The industry supports more than five million Kenyans.

“There is a severe drought affecting everything, not just tea,” said Lerionka Tiampati, the managing director of the Kenya Tea Development Agency, the single biggest tea producer in the country.

In an average year the agency produces about 200,000 tonnes of tea, or three fifths of the country’s entire crop. “Our output is down by 30 per cent, but the problem is not just here in Kenya,” Mr Tiampati said.

The world’s key export auctions are in Mombasa, Colombo in Sri Lanka and Calcutta in India, but all are reporting a reduction in volumes reaching the world market.

However, there may be hope for tea-lovers who are being forced to pay record prices for their daily cuppa. Many smallholders have fought the drought by pruning tea bushes to save them from drying out entirely.

If the rain comes in October, as meteorologists are predicting, these bushes will spring back into life.

“The whole country’s going to be swamped and prices will drop like a stone,” predicted Mike Shaw, a smallholder whose family has grown tea in the hills of Limuru for generations.

Paying the price

— The Kenyan drought is being felt by British shoppers who may soon have to pay more for their tea

— Prices have barely changed in the past ten years because of overproduction of the crop

— The average price for a supermarket own-label pack of 80 teabags, or 250g of leaves, has risen from £1.97 in January to £2.20 last month

— Industry analysts believe that the price could hit £2.25 because of poor weather in the main producer nations

— Britain is second only to Ireland in tea consumption per capita — about 165 million cups are consumed every day, compared with 70 million cups of coffee

Valerie Elliot, Consumer Editor

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