Do you have a plan in the event of a "Roaster Fire"?


#1

Just as an opening thought, this topic is aimed at raising safety awareness (especially for people who are totally new to coffee roasting). For the old-timers, your experiences as coffee roasters and Aillio’s thoughts are most welcome in this thread.

This is a topic that is sometimes not discussed with home roaster equipment in user forums. It is a well known safety requirement with commercial coffee roasters and those in that biz. Even for “home-roasters”, it is important that you know what you will do in the event of a roaster fire. Many of us roast indoors in our homes, basements, garages, out-buildings, etc. The old adage “an ounce of prevention is worth a pound of cure” comes to mind here.

If you think it is unlikely that you could have a fire in your roaster consider what happened to me many years ago (when I was a newbie). Basically, I had a roaster fire in a 1/2lb Drum Coffee Roaster and had not known that roasted coffee would burn (very well). Imagine roasting as normal, reaching the end of the roast when bean temps are at their highest and suddenly you lose power. Power outages are something that we don’t control from the power company. There is also the possibility of an electronic failure in our roaster that stops the operation and sets up the same scenario.

In my case, it was a power outage from the Power Company in my area. The beans in the drum were no longer spinning, no exhaust fan running and within a few minutes I had a fire in the roaster. That particular roaster had plenty of air inlets to feed the fire. I witnessed how well coffee beans will burn when they have reached a temp of ~497F. Chaff also burns very easily, so keeping the Chaff Collector properly emptied is equally important. By the time I realized that my un-powered roast was increasing in temperature, carbonizing and reached a flash point, I had flames inside the roasting drum. If I’d had just a simple plant spray water bottle at hand, I could have cooled the roast right after having lost power.

I learned a very valuable lesson that day. I was fortunate that I got the fire under control and observed that coffee can burn quite well. Today, with my Bullet, I have a large spray bottle with water at the ready in case I ever need it. My plan would be to unplug the roaster and quench the fire with my water spray bottle. I also have a Type A, B, C fire extinguisher (if needed as a backup) within easy reach near where I roast.

The Bullet is a fairly closed unit with exception to the charge inlet, exhaust outlet and drop door. I don’t know how well it would do at limiting oxygen to a fire and do understand that a fire needs oxygen to burn. If Aillio has done testing on this subject, I’d love to hear what they know/advise too. If you have ever felt that the “dead man’s alarm” on the Bullet (aka error message “A-02”) is a bother, just remember that it has a very useful purpose. Think unexpected distraction (while roasting) or maybe a health problem where the Aillio’s ability to shut down the roast for you could be a life saver.

Here’s a blog post from Scott Rao on this topic that was primarily aimed at commercial roasting, but also has some good points on the subject.

The Most Important Thing Few Roasters Bother to Do

I hope this thread will at least help new roasters. Enjoy your roaster and at the same time be prepared in the event of a problem. :fire_extinguisher:


#2

Good topic. Thanks for launching it.

Like you, I keep a spray bottle of water nearby when roasting. It was something I picked up from (I think!) the SweetMarias.com web site or from one of their videos. And it was recent. The realization I was dealing with a potential fire hazard had never entered my head even though I used a propane BBQ grill for several years. That water bottle would have been totally inadequate if I’d had an issue with those burners lighting off something besides beans, so when I read the suggestion for non-propane heated roasters I bought the water bottle and felt like I’d dodged a bullet (no pun intended!).

I have a different situation than most roasters in that I live full time in an RV. I have regulations I have to follow relative to fire safety that includes keeping inspected fire extinguishers around. But an escalating fire situation with a fire extinguisher inside the trailer won’t make it immediately available where I roast. I need to revisit this whole thing- probably add (yet another!) fire extinguisher stored adjacent to the roaster. The thought of cleanup after using one is discouraging, but it beats losing more than a batch of beans or a roaster.

This subject deserves more thought than I just gave it to prepare this reply. I need to ponder this more. Thanks for starting this thread.

Bruce


#3

Great topic.

Before the Bullet, I use to carry a smaller roaster into the kitchen and place on the top of the flat surface stove to make use of the exhaust fan. Now, when I roast using the Bullet, I roll it on a cart to make use of the exhaust fan.

This thread just made me realize that I park the cart right in front of the cabinet door that has the kitchen fire extinguisher behind it. :scream:

Thanks for the reminder.


#4

I have a fire extinguisher, oven mitts and a big metal tub to dump hot things in. I know which plug to pull if it’s an electrical thing.

But the smoke— wow that’s a lot of thick, choking smoke that can get out of control quickly indoors. Ventilation is something I need to improve.


#5

Ah-hah. “… and a big metal tub”. I have a plastic trash can which would likely become part of the problem instead of any kind of solution. I better rethink that.

Yeah… smoke. 50 years ago I had a tiny electrical fire on my new boat (hot insulation) caused by a poorly wired electrical outlet during the build. My wife was home and let out a hoot that brought the neighbor who saved the day. He was still coughing and his eyes were still red & watering when I got home 4 or 5 hrs later. We had to wash the walls to get rid of the smoke residue. I have to believe that was tiny compared to what could come from 2 lbs of burning beans.

There is at least one firefighter that visits here from time to time (I hope he’s not shaking his head in despair reading our thoughts). I’d sure appreciate some input from a person that has some training.

Bruce


#6

When I had my roaster fire years ago, I was totally unprepared for it since I’d not considered the effect of a power outage. It was surprising how quickly my interrupted roast went from “crap, what a time to lose power” to “my beans are on fire”. :fire:

Thanks for sharing your experiences too. :+1:


#7

I haven’t thought about the power outage problem either, until now. Thanks for that.

I guess the thing to do is dump the beans immediately when the power goes out.


#8

Yes, probably need to do that. There is a problem, though…

With a power outage, the drum isn’t turning and the beans won’t migrate to the door (at least not all of them). Probably need to lift the rear of the roaster which means allowing access and something besides the cooling tray to catch the beans. The cooling tray won’t permit the roaster to be tipped as there’s zero clearance between the front of the roaster and the top of the cooling tray. Moving the cooling tray out of the way requires disconnecting its power cable (unless you rip it out of the way and repair the cable later). Every time I go thru the scenario I find it not at all easy to plan an exit strategy if what you’re dealing with is beans that are hot enough to ignite when they hit a lot of fresh air.

Maybe I’m over-thinking this. If the beans aren’t near that magic number of 497°F then just take the time to disconnect the tray and tip the roaster to dump the beans into a metal tray. Not sure how long you have before the residual heat in the drum heats the beans that are in drum contact enough to start the combustion when close to 2nd crack.

A CO2 fire extinguisher (type BC) would be in my future if it weren’t that the space I have is very confined (about 50 sq ft floor area. CO2 isn’t recommended for confined spaces since it’s an asphyxiant.

This is a lot harder than I thought.

Bruce


#9

There are a couple of factors to consider that affect how much time you will have to react. These days, I typically roast 1lb batches and dump my roasts either before 2nd C starts or right after the first few snaps of 2nd. My dump-temps are ~408F. However, with beans (and drum) that hot and no drum or air movement, it won’t take long for the temp to spike. We probably do have a brief window to attempt a dump and cool of the beans assuming that the problem was caught right when it started. As you said Bab, it may not be “easy” to do.

The main thing is to have some sort of plan if (or when) it happens. I think the answer (for me) is to apply a few quick sprays of water on the beans to get temps calmed down. Then I can set about dumping the beans manually in a less stressful situation. A little spray water will likely evaporate as steam and not reach anything that could be damaged is my best guess.

Hopefully, I’ll not need to re-live the experience with my Bullet. But, I do think about losing power during a roast session since it does happen occasionally where I live. :electric_plug:

I’ve thought about a CO2 extinguisher too as my last resort if “plan A” didn’t work.


#10

I roast to about 210C so I’m not terribly concerned, but I still have water nearby and an extinguisher in the next room.


#11

Several years ago there was a commercial roaster available that was a fluid bed design (don’t recall the company/designer’s name) that had a unique feature to address firevsafety.

His design included water spray as the beans are dumped to immediately drop the temp. Apparently it was not uncommon to have the beans exit the roaster and ignite when they hit the air. It also stopped the roast instead of allowing significant time for beans to continue the roasting process because of residual heat. He was convinced that using sprayed water for the right amount of time and in the right way was both safer and better for roast consistency. I remained convinced (prejudiced?) that water on the beans was the kiss of death but had no objective reason to believe his design & process was wrong. (He was a process engineer and I have no experience in that field.)

I have no intention to head in that direction but it is an interesting safety feature that apparently benefitted the product.

Bruce


#12

I’m like you, I only would spray water to avoid a fire. Using water cooling as part of the normal roast process makes the bean-hair on the back f my neck stand. :exploding_head:


#13

I assumed the heat source during roast was a lot hotter than anything I was aware of. It is/was a commercial roaster so heat capacity is probably outrageous.

Bruce


#14

A fire blanket might be another option. Removes the oxygen and smothers the fire without chemicals. I keep one in my kitchen, and I am ordering a larger one (48x48) to keep in the garage where I roast.


#15

Excellent suggestion that I hadn’t thought about. I’m going to add that to my tools (today) for both my indoor roasting and for the home in general. Thanks! :+1:

I was roasting in the basement last night after sundown. I realized that if I have a power outage (while roasting), the flashlight was not nearby and I’d be fumbling in the dark for some light. So, I moved it over within easy reach of my roasting station. Just this morning I had a fresh reminder/example of our local power going out unexpectedly.