Smoking a Barrel

29 Aug 2014

The Albany Brew Crafters is running a Barrel project. In the first brew in the project, several brewers made a Russian Imperial Stout that aged for about six months. I’ve only had a sip, but it was delicious.

After this brew, the barrel project landed in my lap. As did the barrel:

The Barrel

The antics and drama with this barrel have been many, and I’ll share more stories later, but one particular story is important enough to call out on its own, as a public service.

Barrels need to be kept wet, so the wood swells and is watertight. But when empty, a wet barrel is fertile ground for mold and bacteria. The typical solution is to flood the barrel with SO2, which inhibits this growth. Wineries and large breweries do this with a magic wand that can inject SO2 from a tank.

For smaller operations, there are sulfur wicks which can be burned to produce SO2. The Internet is rife with warnings that burning a wick in a barrel full of alcohol vapors is explosive. There are also warnings that if the wick falls into a wet spot on the barrel it will produce sulfurous acid which must then be neutralized through an alkaline rinse followed by a citric acid rinse. But I cannot find one warning about the dangers of inhaling SO2.

After cleaning and drying our barrel, I returned to the brewery to burn a sulfur stick. I rolled the barrel outside for adequate ventilation, but in the slight breeze had trouble getting matches to stay lit. After a few tries I saw some darkening of the sulfur stick, but in the bright sunlight I couldn’t tell if it was burning. I leaned in for a closer look, and got a lungful of SO2. My throat burned, and I coughed quite a lot.

The MSDS for Sulfur Dioxide is not a pleasant read just moments after having inhaled it. The stuff is highly toxic, and reacts with anything wet – such as mucous membranes or even your skin – to produce a corrosive acid.

My cough subsided quickly, the burning in my throat was minor, and I wasn’t having any trouble breathing, so I decided not to seek medical attention immediately. The next day, though, I had a terrible headache that became a fever, so I did visit a doctor. He wasn’t able to determine whether the fever was related to the inhalation, but cleared me of the respiratory side-effects of inhalation. Lost time from work, medical bills, and sick over a long weekend: a big price to pay for a batch of beer.

So if you haven’t figured it out, the moral of the story is: When handling a sulfur wick, take every precaution to avoid inhaling or exposing yourself to the vapors.

In particular:

  • Burn it outside
  • Don’t work alone
  • Wear impermeable gloves
  • Keep your face well clear of the wick
  • Stay upwind

P.S. In all the excitement, I dropped the half-burned wick into the barrel, as it shrinks while it burns and came loose from the wire holder I constructed. That poor barrel may be a planter soon!