The crop has been part of these lush mountains since the late 1890s, when British colonial settlers introduced it.
The area is now famous for its unique, top-rated coffee.
Growing berries is time-consuming – picking, pruning, weeding, spraying, fertilizing and transporting products.
“Coffee requires your full concentration, especially when it starts to flower,” said Mr Macharia.
“From now until the day you’re going to harvest—those six months are your full time on the farm.”
A coffee tree is a huge investment for cash-strapped farmers, as it can take four years for the fruit to ripen.
The cost of a cup of coffee in a posh European cafe, usually $4 (£3.20), highlights the stark difference compared to the wages of many Kenyan gentlemen who earn no more than $2.30 a day.
This is confirmed by Edith Mwangi, who harvests coffee cherries on the red earth hillside above the processing plant.
“They don’t know the poverty we suffer from. To survive, you have to fight day and night,” she said.
With four children dependent on her, Ms Mwangi works six days a week, earning about $1.40 a day.
She has to walk 5 km (three miles) to reach the farm where she works.
