WhereAlfenas, southern Minas Gerais, Brazil
Since1993
FamilyProduction drums
History
Rototec was born in 1993 in Alfenas, in southern Minas Gerais, in the midst of coffee plantations. Its “A Empresa” page, archived in April 2001, says where it comes from. It began with special projects and maintenance on processing and packaging lines for foods, powders and granules, coffee in particular. The order is the reverse of that of the large European companies. Rototec repaired other people's machines before selling its own, and it is the region that taught it the trade. This origin still shows in the federal registry, which leaves it the maintenance of food machinery as a secondary activity. The same 2001 page mentions a technician who then had more than twenty years in the sector. The workshop has never moved, Rua da Liberdade 153, and remains a microenterprise in the federal registry, fifteen thousand reais of share capital. The 2001 catalog presented itself as “special projects on request” and already covered the whole chain. Its roaster of the time took sixteen kilos per charge. The range then narrowed toward the bottom. In March 2009 as in August 2019, the largest model in the catalog is the RT-12, twelve to thirteen kilos. The turning point is recent. The redesign of the site, built on WordPress in October 2020, brings up the RT-15 Master and the RT-30. The complete kit is announced right after, as a 2021 launch.
What it makes
Rototec makes drum roasters heated by LPG, liquefied petroleum gas sold in cylinders. The manufacturer says nowhere whether the flame licks the drum or heats a separate chamber. It publishes neither a cross-section nor a diagram. What it puts forward is a “micro-flame technology,” that is, a burner that drops very low in power without going out. It also announces digital control of airflow and drum rotation speed. These two settings govern the share of convection, the heat carried by the air passing through the charge, against conduction, the heat transmitted by contact with the metal. The 2001 roaster was entirely lined with glass wool, against losses through the wall. The RT-14 cools by drawing air through the charge. For the RT-5, the sheet says only “air-cooled,” without specifying the mechanism. The two large machines have a circular cyclone cooler and a chaff collector, which removes by centrifugal force the silverskin detached from the bean. They also carry an “explosion-proof system” that the manufacturer does not explain. The term usually designates protection against ignition of chaff and dust accumulated in the ducts. Around the roaster, the company builds the whole chain: mills, carbon steel silos, pneumatic elevator, dosing and bagging machine, vacuum sealers and a machine to remove the pellicle. The federal registry classifies it under manufacture of machinery for the food industries, not trading, which rules out the reseller hypothesis.
The models
Four roasters in the 2026 catalog. The RT-5, 5 kg per batch, twenty minutes, 1/4 horsepower WEG motor, or about 184 watts, LPG heating, air cooling. The RT-14, charge of 12 to 13 kg, thirty minutes, air-cooled, 0.37 kW for the suction, in 110 or 220 volts, with a variant with cooler and mixer. The RT-15 Master, 15 kg in twenty minutes, 1.75 m high. The RT-30, 30 kg in twenty minutes, 2.10 m high. These last two add the circular cyclone cooler and the chaff collector. They also add electronic control of temperature and time, adjustment of motor rotation and an input for curve software. The RT-14 was called RT-12 until August 2019 at least, at identical charge. Around them come the SM-40 mills, 40 kg per hour, and SM-80C, 80 kg per hour. Added to these are silos of 10, 15 and 20 sacks and a pneumatic elevator. Then the RT-52 bagging machine, given at 300 or 350 kg per hour. Finally the RT-10 double-chamber vacuum sealer, up to 700 kg per hour. And the RT-80, which removes the pellicle, given at 250 per hour in a faulty unit.
What you gain
The published consumption figure comes down to a calculation. Thirteen kilos of LPG for 450 kg of coffee make 29 grams of gas per kilo, or about 1.3 megajoules. Yet drying a kilo of green coffee and bringing it to 210 degrees takes about 0.6 megajoules. Nearly half of the burner's heat would therefore reach the bean. The same calculation gives an average burner power of around 9.6 kilowatts, on thirteen kilos in thirty minutes. The order of magnitude is useful: it says which cylinder to plan for and which gas flow to install before ordering. The micro-flame drops low in power, so a half charge does not force the burner to be shut off and relit. On the two large machines, the digital control of air and rotation shifts the share of convection without touching the mechanics. The cyclone cooler draws air through the bed of beans, which quickly halts the residual roasting.
What you lose
The catalog publishes neither drum diameter, nor rotation speed, nor burner power in kilowatts. We therefore do not know, before buying, whether the flame touches the drum or not. The RT-5 and RT-14 have neither electronic temperature control nor an input for curve software. You roast by nose and by watch, and the profile cannot be replayed from one batch to the next. For the RT-15 Master, no gas consumption is published. For the RT-30, the only published value appears on the kit page, and it repeats word for word that of the RT-14. A copied figure tells nothing about the machine. The ceiling remains thirty kilos per batch, with nothing above. The sheets finally carry old errors, an RT-5 110 millimeters tall, an RT-80 given in kilometers per hour. These typos were already online in 2019 and survived the redesign.
Gray areaThe founding date is the contested point, and it was settled against the manufacturer. The current site states “Desde 1985 no mercado,” with a counter of “more than 35 years.” Two independent sources say 1993. The federal registry sets the start of activity at December 14, 1993. The company itself wrote “Foi fundada em 1993” on its own page, in 2001. The 1985 figure appears in no archived version of the site between 2001 and 2019. It surfaces with the 2020 redesign, and the first capture that carries it dates from December 23, 2021. Its origin is not documented. One possible but unverified explanation would be that it counts the founder's career and not the age of the company. The 2001 page does mention a technician already with more than twenty years in the trade. The founder's name remains unknown. Marcio Siqueira was the domain contact as early as May 2005, David Coelho Siqueira has been the managing partner since January 2023. Their family relationship is only a coincidence of surname between two registries. A customer testimonial thanks “Elionara e Davi,” but nothing establishes kinship. On the technical side, the company never says whether its drums are direct-flame or indirectly heated. It publishes neither drum diameter, nor rotation speed, nor burner power. The announced “diameter” is 1.30 m for the RT-30 and 0.90 m for the RT-15 Master. The capacity ratio, two, is roughly the square of the diameter ratio, 1.44. That is a surface law, not a volume law. It would rather suggest the circular cooling tray than the drum, whose volume would grow as the cube. No document confirms it. The energy calculations in the “what you gain” section rest on two assumptions. The first is a calorific value of 46 megajoules per kilo of LPG. The second is a theoretical requirement, calculated and not measured, of about 0.6 megajoules per kilo of green coffee. The resulting efficiency, close to half, is flattering for a small gas drum. The announced consumption therefore remains a manufacturer value, never verified by an independent test. The change from the RT-12 to the RT-14 has remained unexplained. The charge stays at 12 to 13 kg. But the announced roasting time goes from twenty to thirty minutes. The gas yield, for its part, goes from 250 to 450 kg of coffee per 13 kg cylinder. At least one of the two figures changed with no stated reason. The complete kit page, moreover, contradicts the RT-30 sheet. It credits it with 120 kg, 1,600 mm long, 1,150 mm high, 560 mm wide and four 0.5 horsepower motors. It also attributes to it the consumption of the RT-14, thirteen kilos of gas for 450 kg of coffee. These values would suit the RT-14, not a machine announced at 2.10 m high. The catalog carries old typos never corrected, an RT-5 110 millimeters tall, already so in 2019, and an RT-80 given at “250 km/h.” The name of this RT-80, descascador de película, does not say either on which product or at what stage it works. The ten export countries are listed nowhere, and the counters of 1,000 units and 500 customers rest only on the company's word. Finally, no patent or trademark search could be run. The session's web search quota is exhausted and the public search engine of the Brazilian INPI cannot be queried without a browser session. Whether or not Rototec filings exist therefore remains unknown. No independent test or trade press article was consulted.
Manufacturer's website, rototec.com.br, single page organized in sections “Quem Somos,” “Nossos Produtos” and “Kit torrefação completa,” accessed September 18, 2026, for the capacities, roasting times, LPG consumption, motors, dimensions, micro-flame, digital control of air and drum, the counters of 35 years, 1,000 units and 500 customers, the mention of more than ten countries and the testimonial citing “Elionara e Davi”; REST interface of that same site, /wp-json/wp/v2/pages, accessed September 18, 2026, which declares only one page, created on October 19, 2020 and modified on November 17, 2020, which dates the redesign; same site, “empresa.htm” page archived by the Internet Archive on April 8, 2001, its oldest preserved capture, for the sentence “Foi fundada em 1993,” the initial activity of special projects and maintenance on processing and packaging lines, and the technician with more than twenty years in the trade; same site, “roto_torrador.htm” page archived on April 12, 2001, for the 48 kg per hour roaster with a 16 kg charge, the full glass wool lining and the heading “projetos especiais mediante consulta”; same site, “torrefacao1.html” page archived on March 7, 2009 and August 6, 2019, for the RT-12, charge of 12 to 13 kg, twenty minutes, 13 kg of LPG for 250 kg of coffee, and for the RT-5 already given as 110 millimeters tall; capture of the current site of December 23, 2021, the first preserved after the redesign, for the presence from that date of the RT-30, the RT-15 Master and the mention “Desde 1985”; Brazilian federal business registry, CNPJ 71.419.691/0001-00, queried through the public BrasilAPI interface on September 18, 2026, for the corporate name Rototec Eletro Mecânica Ltda, the start of activity on December 14, 1993, the single establishment Rua da Liberdade 153, Vila Betânia, in Alfenas, the main activity code 2862-3/00 “manufacture of machinery and equipment for the food, beverage and tobacco industries,” the secondary code 3314-7/19 for maintenance and repair of those same machines, the microenterprise status, the share capital of 15,000 reais and the managing partner David Coelho Siqueira since January 3, 2023; Brazilian domain name registry, RDAP service of registro.br for rototec.com.br, accessed September 18, 2026, for the domain registration on May 3, 2000 and the administrative contact Marcio Siqueira, registered May 23, 2005