Humidity In Aging Warehouses

A friend of mine recently told me of a tour he did at the Hayner Distillery in Ohio. He stated that before Prohibition, at the original Hayner Distillery, they heated the warehouse in the winter and during the summer, they sprayed the barrels with water to keep the wood wet and tight to reduce the angel’s share in the warehouses. I had never heard of any distillery doing that. I looked into it and did not find any other reference to a distillery wetting their barrels in the summer. I do not think that wetting the barrels is a good idea.

The whole point of the barrel rack developed by Stitzel is that it increases the air circulation in the warehouse. Damp air and moisture of any sort can lead to the growth of mold in the warehouse and results in musty tasting whiskey. This is why distilleries open all of the windows in the warehouse during the summer to increase the air circulation.

When I was at United Distillers in the early 1990s, they were tasting every barrel at Stitzel-Weller to look for musty whiskey. They were over half way through with the project when I started at Stitzel-Weller full time, but I was still able to go to the quality control trailer where the project has being staged, for about six months. In that time we found many bad barrels of whiskey that were then taken to be redistilled as ethanol.

So what caused those musty barrels? There were two major sources for mustiness in whiskey. The major culprit at Stitzel-Weller was a bad truckload of corn that somehow got past the quality control checks back in the 1980s. The other cause was moisture from some broken windows in the warehouses allowing rain into the building. Moisture is the main cause for musty barrels. It most often happens when a window glass gets broken. It also happens to distillery warehouses that are located on a flood plain and flood waters get into the warehouse. That is why distilleries like to build warehouses on high ground when possible.

Musty whiskey rarely gets bottled. If it does, then someone in quality control messed up. That is why quality control checks are done by a panel of people. They don’t want one person with a head cold miss that nasty, musty smell in the samples. They also look for people who are sensitive to the smell. I have known people who can detect even the slightest aroma of mustiness. They are all prized employees of the quality control panel.

So what does must smell like? It is a very earthy and moldy aroma. Think of old newspapers or cardboard in a damp basement. A “corked” bottle of whiskey is a very strong musty odor and taste. A bottle can become “corked” when the cork used to seal the bottle has mold on it. It is not a very pleasant taste at all. It happens from time to time and can ruin a fine bottle of whiskey.

I believe Hayner may have wetted their barrels during the summer, but the fact that other distilleries did not, and do not, use this process, shows that it was not a good idea, If they were using a wooden rack warehouse, as most distilleries were after the 1880s, then that constant moisture in the warehouse would have caused mold to grow and even the wooden racks to begin to rot. It may have saved some angel’s share, but that savings would have been negated by the amount of musty whiskey they produced and the damage done to the warehouse.