All over the owner's manual it states, “Never leave a Roaster unattended while in operation.” Flipping though the owner's manual I saw it at least seven times! Annoying? Maybe, but most every roaster I have seen has that warning in the owner's manual and some have it printed right on the roaster. There is a very good reason for that:



    This roaster suffered a significant fire. After the fire it actually roasted a test batch of coffee after one small temporary repair, but it was an expensive repair job.

No one was hurt and there was no property damage, but things could easily gotten much worse.


    Operating a coffee roaster is not like most other appliances. Coffee is quite unique because by the time most desirable roast levels are achieved the beans are very dry, becoming something akin to like little bits of oily firewood. Some roasts will top 400F and that is not very far from their ignition point. 

    Being prepared is discussed in the owner's manual as well. Not roasting near flammable materials and having a pump bottle of water at hand can go a long way towards handling an ignition event. But the best way is to avoid that situation.

    Keeping the roaster clean, not roasting too dark, and following the cleaning and care instructions in the owners manual are all part of prevention. Knowing the beans you are roasting is another. Beans vary in their nature and not all beans roast in the same, predictable manner. Processing and age are just two of the factors to consider. Different roasting appliances also will react in different ways, and the same beans roasted for the same amount of time, and showing the same bean temperature during the roast can mean one is done and ready to eject one is in flames. 


So, What Does “Attended” Mean?


    When we say never leave the roaster unattended it means just that. Give the roaster your FULL attention until the roast is completed. Attended means being right there, personally and closely paying attention to all factors, all the time, throughout the entire roast. Here are just a few things you need to be aware of:

  • Rate of temperature change
  • Bean color
  • Bean sounds
  • Nature of and amount of smoke
  • The aroma of the smoke
  • Temperature of the beans

    Attended DOES NOT mean talking on the phone. It does not mean cooking dinner and glancing over at the roaster. You might compare it to the attention needed when driving, but as a long-time motorcyclist I can say that this may not be the best comparison for some people.

    One factor that has come up more than once is the reference to programmed roasts that the user has saved and used many many times. Suddenly massive amounts of smoke pour from the machine! If the user had been IN ATTENDANCE, right there at the roaster they would have noticed that the smoke suddenly increased and smelled very differently. What changed? Long-term, multiple roasts to a very dark color caused a change in airflow and possibly the carbonized coating on the thermocouples slowed their reaction and the displayed temperature was off. Maybe the ventilation fan was moving a bit slower then when new. The end result was a repair bill that was right around $500 in parts and labor to replace a number of melted plastic parts and get the roaster back to operating condition. 

    In school, attendance meant at your desk, paying attention, ready to go to work. Don't be marked “absent” when you are roasting. The consequences can be worse than being made to stay after school.