The Silent Killer

by Tom Altenbach

I have a dedicated indoor homebrewery, in the laundry room. Doors from the brewery open to the garage, a bathroom with a small window, and the family room with a large patio door. I fire my two brewing stoves with propane from the familiar 5 gallon barbecue tanks. Despite the warning labels, I’ve brewed this way for a number of years. Of course the dangers with propane are two: explosion/fire and carbon monoxide (CO) poisoning.

In the past I always used the tiny ceiling laundry fan to expel fumes and steam, and used a floor fan to bring in fresh air through the family room from the patio door, or from the garage. The bathroom window was also kept open. That should take care of the CO I thought. But at the end of my long brew days, I was always very tired. Grain brewing is a lot of work, but it wasn’t that much work. Of course a fair amount of homebrew is always consumed during brewing, but hey, I can handle that. What about that mysterious tasteless odorless CO gas that was supposed to be vented outside?

I broke down and bought a home digital CO monitor last year, shortly after their introduction to consumers. I happened to find the Nighthawk 2000 unit at Wal-Mart (currently about $40).

After mounting it in my brewery and firing up the stoves, I was shocked to find out how quickly nasty levels of CO built up, even with my usual ventilation running. Although the effects seemed minor, I was not comfortable breathing that much CO. My next purchase was a heavy duty centrifugal exhaust fan, mounted in the bathroom window with ducting to the brewery. With that running, and fresh air provided with flow-through from the garage and/or family room, I can breathe again. And I’m not as tired at the end of the brew day.

I can’t over-stress the importance of a digital CO meter for fire-brewing in any enclosed space: house, garage, workshop, basement, or homebrew shop. Merely having doors and windows open is not good enough to prevent poisoning. Even my original two-fan arrangement was not good enough ventilation. the digital readout on the Nighthawk is great, because it lets you see the CO buildup immediately and allows you to take action to reduce it before it gets to alarming levels. I would not want to be brewing without the CO monitor.

For more information on various CO monitors, see the Consumer Reports July 1995 issue. Of ten monitors evaluated, the Nighthawk 2000 ranked first.

Here’s another warning I haven’t seen before. Be careful not to over-tighten the shutoff valve on the propane tank. I did exactly that, using just my hands. (I can break almost anything with my bare hands --- what strength!) Upon trying to open the valve, I found the threads stripped on the valve handle. Then the valve failed, stuck in a partially open position. This precipitated not just a leak, but a major propane blowdown when I disconnected the tank from the stove. Fortunately, the blowdown was outside, and my neighborhood is still intact.

Hoppy Holidays to all, and have a Safe Brew Year.