Diedrich Coffee Roasters

Diedrich RoastersMaine Coast Roast proudly uses a Diedrich Manufacturing Infrared coffee roaster. Diedrich Manufacturing has been the leader in infrared coffee roasting equipment for over half a century. 


During the typical commercial roasting process natural acids are produced that can produce heartburn sensations and upset stomach to some with sensitive stomachs.  However this need not be so.  Typical commercial roasters run the coffee along a conveyor belt system and blow hot air from a gas flame manifold beneath them.  Kind of like some hamburger chains cook their hamburgers.  Another is to simply tumble them in the gas flame heated hot air like a commercial dryer used at the cleaners.  Both of these types of roasters tend to “burn” the bean causing an unevenness in the roasting process that does not fully remove these acid producing compounds.


The vast majority of coffees available today, even most specialty coffees are roasted in the manner described above.  As I said earlier, our less common infrared roasting technique is only used by an exclusive class of roasters,  approximately 5% of all specialty coffees produced.

Here are a few other remarkable improvements our infrared roaster produces in your daily cup: 
  • The beans increase in temperature quicker than those roasted by hot air. Studies have shown that compared to conventional roasting, infrared roasting showed less increase in radicals on the bean during and after the roasting process.
  • Highly noticeable was the consistent formation of brown colored compounds showing the bean was uniformly heated and never burned.
  • The infrared roasted beans had a quick increase in the internal temperature and thus suffer from less damage on the surface.
  • The study also revealed a uniform and quick decrease in moisture and showed the beans undergo uniform heating even at the core.
  • Even more noteworthy were the changes in the contents of citric acid, malic acid and formic acid that are naturally found in the bean. When monitored and compared to conventional roasting, infrared roasted coffee beans showed changes from an earlier stage. As the roasting proceeded, the infrared roasted coffee beans contained these acids in a smaller amount!
  • Not surprisingly, the content of aroma compounds were found to be 25% more than that of conventional roasting, and when tested was found to carry the same standard to the cup. The taste from the extract of hot air roasted coffee beans was similar to most conventional roastings, while the extract of the infrared roasted coffee beans was different from them (i.e., weaker acidity) leading to a better coffee without a bitter taste.
Infrared roasting is the superior method to roast coffee. Our Diedrich Infrared roaster heats the coffee faster, more uniformly and at relatively lower temperature than conventional hot air/flame roasters.
The result is a low-acid, pleasant cup that is consistent bag to bag year after year.