By Maggie Kimberl

The corn supremacy

Quality is a top priority when it comes to corn
Bourbon starts with corn, which makes it an agricultural product. Agriculture is subject to shifts in weather and climate as well as market prices, and quality can vary because of dozens of different factors. Because of this, corn is often tested rigorously before a distillery will accept it, and these quality control measures are often part of distillery tours.

Each distillery has its own testing process, and the differences between large and small distilleries might be surprising, especially when it comes to those small distilleries that grow their own corn. Large distilleries often test for things like mould, moisture content, and the presence of diesel fuel that could have entered somewhere in the harvesting or transportation of the grains. Smaller distilleries also have these concerns, but those that grow their own corn take on the responsibility for the earlier stages of the corn, as well.

“Our corn quality is an important part of our recipe,” says Buffalo Trace distillery manager Josh Wheatley. “We use non-GMO U.S. #2 Yellow dent corn and ensure each delivery of corn meets our quality standards. The Yellow class corn we use contains no more than five per cent of corn of other colours. Yellow kernels of corn with a light tinge of red are considered yellow corn. We inspect the corn based on a number of factors. The maximum amount of moisture we accept is 14 per cent and anything higher is rejected. The test weight has to be at least 54 lb/bu and contain no more than a maximum of 0.2 per cent of heat damaged kernels. Also, the total amount of damaged kernels and foreign material cannot exceed three per cent.”

In a large-scale distillery such as Buffalo Trace, corn is sourced from multiple farms to ensure there’s always a steady supply to keep the plant running. It comes in on tractor trailer trucks, often multiple times a day, just to meet the basic demand. Each truckload is inspected for quality.
“We make each determination of class, damaged kernels, heat-damaged kernels, and dent corn based on the grain after the removal of the broken corn and foreign material,” says Wheatley. “Other determinations not specifically provided for under the general provisions are made on the basis of the grain as a whole, except the determination of odour which is made on either the basis of the grain as a whole or the grain when free from broken corn and foreign material.”

Often quality control starts from the ground up. “We take our corn seriously,” says Jeptha Creed owner and master distiller Joyce Nethery. “Our quality control process actually begins with the soil. We rotate our crops, alternating between corn and beans, (the legumes nourish the soil by adding nitrogen from the air) and use cover crops to keep the soil healthy year after year.”

Working with heirloom corn can be yet another challenge to account for. “Since we use an heirloom varietal,” explains Nethery, “our corn is open-pollinated and we get to select the seeds that we save. We select seed from the best fields and additionally select by separation for the best kernels. Throughout the process we keep a close eye on the corn health: we check as the seed is going into the ground, when it’s sprouting, as it’s growing, before we harvest, after we harvest, before it goes into the grain bin, while it’s in the grain bin, and so on. We check the corn quality at every stage.”

Farmer distillers have to ensure every step nurtures each kernel of corn. “We’ve invested a lot of money and time so we get a very clean harvest,” says Nethery.

While larger distilleries can get corn on the open market, farmers feel the full brunt of any growing, harvesting, or storage issues. “The downside to growing our own corn is that, to a degree, we’re at the mercy of Mother Nature,” Nethery points out. “This year the rain was so heavy in the spring that we couldn’t get the corn into the ground until June, and then this summer it’s been extremely dry. So there is a potential for a poor yield this year. Thankfully we’ve got a year’s supply of our corn in storage.”

It takes quality corn to produce quality Bourbon, and each distillery has its own quality control methods.