JM Estrada S.A.

History

The date of 1865 is not that of the Estradas. It is that of the Ferrería de Amagá, in Antioquia. After Colombian independence, families of Marmato lost their mines, expropriated. The Ospinas, one of them, founded in 1865 an ironworks, that is, an iron foundry, to make mining equipment. It first cast California mills, those stamp mills whose pestles crush vein ore, for mines like the Zancudo. The manufacturer credits the ironworks' Pelton wheels to Pedro Nel Ospina, a mechanical engineer trained at Berkeley. He was its manager, then president of the Republic from 1922 to 1926. A mine foundry thus had an engineer able to design hydraulic turbines. It then moved on to trapiches, cane mills, and imported coffee pulpers. The pulper tears the pulp off the cherry to free the bean. These imports cost too much, and the Estradas, close to the Ospinas, decided to cast them themselves. Jesús María Estrada Ochoa was born in 1857 in Caldas, in Antioquia. At nineteen he opened a forge in his native village, and the manufacturer dates this small Caldas foundry to 1876. By 1884 he had raised it to the rank of foundry. It cast Pelton wheels, pipes, cane mills, California mills, pulpers, pulleys and bearings. In 1903 his son Ernesto joined him, on return from a study trip to the United States. The same year the workshop left Caldas for La Estrella, on the bank of the quebrada Grande, a torrent. The reason was mechanical: it needed a waterfall strong enough to drive the machine tools. The Estradas bought the Ferrería in 1927, then ran the two companies separately for twenty-four years. In 1931 the whole was the largest mechanical engineering company in the country, according to an industrial supplement of the daily El Colombiano of Medellín dated October 13, 1931. The two companies merged on February 9, 1951, under the name Hijos de JM Estrada Ltda. Jorge Eduardo Estrada M., great-grandson of the founder, signs the company's text today.

What it makes

The La Estrella factory had 7,800 square meters built and 230 people in March 2020. The company keeps a design office and its own foundry, which casts the parts of its machines. Jorge Estrada summed up the rule then as follows: nothing is sent out to be made outside. Coffee accounts for 65% of sales, and the post-harvest processing machines go to thirty countries. All production has switched to stainless steel, for a stated reason: coffee is a food and must be treated as such. Stainless steel also holds up better over time, which a job in Kona, Hawaii, verified in salt air. The company displays an ISO 9001 certification and an IQNet certificate dated December 2021. The roaster works on the rotating drum principle. A propane gas burner brings the drum to 220 degrees Celsius. The manufacturer's data sheet specifies a double-wall, non-perforated drum. Neither the flame nor the combustion gases therefore pass through the mass of beans: the heat passes through the metal. The combustion chamber is made of refractory steel, announced as maintenance-free. The burner runs on liquefied petroleum gas, with four intensities, and the same sheet also mentions diesel. A fan extracts and recirculates the hot air. The manufacturer sees an energy saving in this, since the recovered heat has already been paid for in gas. Ignition is automatic. The drum body turns on bearings. The frame is stainless steel, insulated with glass wool to limit heat leaks. The whole body of the machine tilts to empty the batch.

The models

The manufacturer gives its roasters no commercial names. It sells three, designated by their degree of automation, plus a mill. The manual roaster takes 1 to 3 pounds of hulled coffee (trillado, in Spanish), or 0.45 to 1.4 kg: the parchment, the dry envelope around the bean, has been removed. It is therefore a green coffee load, and not a yield in roasted coffee. The container and lid are cast aluminum, with a quick-closing system. The crank is vertical and carries internal paddles, so that the bean rolls and roasts evenly. Holes let the steam out and serve to judge the internal temperature. The metal handle is sheathed in wood, so the hand never touches hot metal. The company ranks this device among its own developments, for roasting samples on the farm. Its product page also presents it as a household appliance. The semi-automatic roaster roasts in batches of about fifteen minutes, four cycles per hour. The time is set according to the moisture of the incoming coffee, or by the roaster's judgment. The burner is gas and the machine is stainless steel. A cyclone treats the vapors and fumes and cools the bean. Two refractory glass viewing windows equip the machine. One looks at the mass of coffee, the other at the burner rails, those perforated tubes from which the flames come. One can thus see whether the flame is lit and steady without opening anything. A sampling spoon takes out samples during the roast. A digital thermometer measures the temperature in the mass of coffee, and not that of the air. The cooling tray is of large capacity, which evens out the cooling, and the cyclone collects the dust. A system extracts the silverskin, the fine skin that detaches from the bean during roasting. The automatic roaster repeats the same stated throughput. It has a hopper for loading green coffee and a control panel. The manufacturer describes this panel as a roast curve programmer. A note of November 17, 2021 rather describes nine preset cycles, chosen on a touch screen. Once the cycle is chosen, the machine opens the gas and preheats the chamber to the point wanted by that cycle. It then loads the coffee from the hopper, roasts, sends it to the cooling tray, then deposits the batch at the outlet. Solenoid valves control the gas, and the machine extracts fumes and chaff. The manufacturer announces 20 kg per hour, for the semi-automatic as for the automatic. The load of a batch is never published. A disc mill for roasted coffee is added: 2 electric horsepower, discs at 600 to 900 revolutions per minute, 100 to 120 kg per hour, 34 kg net. It gives fine grinds, but the manufacturer specifies that they reach neither flour nor impalpable powder. It also serves for cocoa, cereals, cheese and condiments. The rest of the coffee catalog covers post-harvest processing. It includes pre-grading and transport, pulpers, the Ecoplus, Becolsub, compact and Ecomill sorting modules. Then manual, solar and automatic dryers, rotary drum dryers (guardiolas, in Spanish), hullers, which hull dry coffee, and water treatment.

What you gain

The non-perforated double wall puts metal between the flame and the bean. No combustion gas passes through the load. There is therefore neither smoky taste nor surface scorching from direct contact with the flame. This mass of metal stores heat. A cold load makes the temperature drop less than with a thin drum. The digital thermometer reads the mass of coffee, not the drum air. The operator therefore follows what actually happens to the bean, without going through an indirect measurement. The window aimed at the burner rails shows the state of the flame without opening anything. A flame-out or a fouled burner is seen at once. Automatic preheating brings the machine to the same starting point at every batch. That removes the first cause of variation between two roasts. Recirculating the hot air reuses heat already paid for in gas. Stainless steel, chosen because coffee is a food, also holds up in a salt atmosphere, as a Hawaiian job showed.

What you lose

The same mass of metal turns against the operator. Changing the burner intensity does not immediately change the bean temperature. The wall must first be heated or cooled. A rise that runs away is recovered in tens of seconds, not in seconds. The four burner intensities are notches, not continuous modulation. Between two notches, there is nothing. The published throughput tops out at twenty kilos per hour, and the catalog goes no higher. The mill, by the manufacturer's own admission, goes down neither to flour nor to impalpable powder. An espresso grind is therefore out of its reach. Finally the company states four design criteria for its machines: compliance with the Colombian environmental standard, quality of the coffee produced, low purchase price, low maintenance. Fineness of roast control does not appear there, and the range shows it.