At the Lower Eastern Coffee Mill (Lecom) plant in Machakos town, we learnt a few lessons on how coffee is milled and graded and how the process can be used to steal coffee from farmers even when the farmers are watching.

Josephat Ngyengya, the man who took us through the process, is the manager of Lecom. He is a specialist in coffee quality control. In fact he is one of the few Kenyans who are certified Q graders, a unique qualification for purchasing coffee, selecting roast profiles, production and processing methods, understanding coffee origins, and more. “It allows us to communicate objectively about quality throughout the entire coffee supply chain, enabling me to taste and grade coffee for specialist markets,” Ngyengya explains as he takes us through the strict quality control that coffee coming to Lecom goes through.

Quality control starts when parchment coffee arrives at the weigh bridge where it is given a weighbridge ticket which identifies it throughout the processing and marketing process. The parchment area is next stop from the weigh bridge where Ngyengya will take a sample of some 300 grams from each consignment for mini milling and coffee tasting. The process of mini milling and coffee tasting will reveal all the details that a buyer needs to make sound purchase decisions. The details also help farmers to know how much care they are giving to their crop and what needs to be done to improve their incomes. “During low seasons, we go out to advice farmers on how to get more from their coffee using this information”, Ngyengya says.

The sample taken will reveal among other things, the moisture content and the expected loss – or coffee recovery percentage. Ngyengya tells us that the ideal moisture content is 11% and is probably a good target for most coffee. At any rate, coffee with moisture content of above 12.5 percent is classified as poor quality, has poor taste and is likely to develop fungi and molds.

On the other hand, over-drying coffee costs money.  Not only is weight, and therefore money, lost unnecessarily, but the accompanying loss of color also translates directly into lower liquor quality. When moisture drops below 10%, aroma, acidity and freshness begin to fade away and at 8% or below they have completely disappeared. For these reasons coffee should not have less than 8% moisture content.

According to Ngyengya, the average managed farm should produce approximately the following grades of coffee when passed through coffee grading screens:

Coffee grade AA — 20 percent

Coffee grade AB ……60 per cent

Coffee grade C…… 15 per cent.

When mini milling is complete, a roasting sample is taken from the 300 grams and is roasted, ground and brewed for tasting. Roasting must be at 150 degrees centigrade.  “If the temperatures are too cool the coffee spoils”. Tasting will establish acidity, bitterness, sweetness, saltiness and sourness. It also establishes body and off-flavors. Acidity comes from the soil while the others come from the processing methods.

Ngyengya emphasizes the importance of proper records in coffee processing. When a new consignment arrives at Lecom, it is weighed and given a weigh bridge ticket indicating the type of coffee, number of bags, weight and an outturn number all of which are necessary to identify the coffee.  When the sample is taken at the parchment area and is mini milled, the consignment is issued with a milling card which contains all the earlier information about the consignment and the findings of the quality control process. “The consignment should always be identifiable showing the date it arrived at the mill, from which factory, the results of milling process and the coffee tasting process. It is important for farmers to be able to confirm that what they brought in is what they get at the end of the process.

The control process ends with the miller making what is called a milling statement that shows details such as the milling loss and recovery for the marketer. He also makes a catalogue with details of the coffee consignment for the buyer. “It is also important for the buyers to know what they are buying and from where,” says Ngyengya.

According to Ngyengya, the average managed farm should produce approximately the following grades of coffee when passed through coffee grading screens:

Coffee grade AA — 20 percent

Coffee grade AB ……60 per cent

Coffee grade C…… 15 per cent.

When mini milling is complete, a roasting sample is taken from the 300 grams and is roasted, ground and brewed for tasting. Roasting must be at 150 degrees centigrade.  “If the temperatures are too cool the coffee spoils”. Tasting will establish acidity, bitterness, sweetness, saltiness and sourness. It also establishes body and off-flavors. Acidity comes from the soil while the others come from the processing methods.

Ngyengya emphasizes the importance of proper records in coffee processing. When a new consignment arrives at Lecom, it is weighed and given a weigh bridge ticket indicating the type of coffee, number of bags, weight and an outturn number all of which are necessary to identify the coffee.  When the sample is taken at the parchment area and is mini milled, the consignment is issued with a milling card which contains all the earlier information about the consignment and the findings of the quality control process. “The consignment should always be identifiable showing the date it arrived at the mill, from which factory, the results of milling process and the coffee tasting process. It is important for farmers to be able to confirm that what they brought in is what they get at the end of the process.

The control process ends with the miller making what is called a milling statement that shows details such as the milling loss and recovery for the marketer. He also makes a catalogue with details of the coffee consignment for the buyer. “It is also important for the buyers to know what they are buying and from where,” says Ngyengya.