New Solutions to Old Problems

Short shelf life and difficult handling characteristics deter ethanol producers from dealing with wet distillers grains.


In business we must take the good with the bad, and rarely does something truly good come along without a hitch. Ethanol producers found this to be true when they discovered that wet distillers grains (WDG) is not only difficult to handle, but also has a shorter shelf life, resulting in a lower valued product.

Since the ethanol boom began, around the late 1990s, producers have found a market for the co-product. WDG, or wet cake, is more palatable and nutritious for dairy cows and cattle than dried distillers grains (DDG), and is the preferred feed of many beef and dairy producers. It also saves the ethanol facility money and energy because there is no need for drying and related equipment. Although the product is a highly marketable feed, it has its downsides — its shelf life and handling characteristics make it hardly an ideal commodity.

WDG can spoil in as little as three days, if untreated and left out in humid conditions. The acidic pH of the product, which consists of about 65% moisture, makes it corrosive to even stainless steel. It also has a tendency to clump together and stick to material handling and loading equipment.

Thanks to innovative thinkers in this industry who are dedicated to smoothing out the road bumps ethanol producers run into, solutions to the short shelf life and difficult handling characteristics have been discovered.

Shelf Life Extender

Although WDG is rapidly becoming a feed favorite of beef and dairy producers, it hasn't always been that way. In the past, farm operators have been cautious because it's known to spoil quickly. Dan Weiland, regional sales manager at Alltech, an industry leader in animal feed, explains how detrimental a poor- quality feed can be to a dairy herd.

"Mold and mycotoxins can have a negative impact on cow health and decrease milk production," Weiland says.

Becky Timmons, director of applications research and quality assurance, sheds some light on why wet cake is so conducive to spoiling.

"It's mainly a combination of the available water and the environment it's stored in. It's usually dumped into a trough or on the ground, and since organisms are abundant there, the sugar, other nutrients, and the ideal pH make it a good medium for bacterial growth," Timmons says.

Even before the ethanol boom hit, Alltech was searching for a way to provide ethanol producers with a preservative that would make wet cake more appealing to dairies and beef producers. In 2002 Alltech senior applications specialist, Michelle Stevens, began researching and developing what later became known as CakeGuard.

CakeGuard protects wet cake from the losses in palatability and nutritive value caused by mold growth and dangerous levels of toxicity from mycotoxins. The feed preservative is applied with either a spray or in a mixer and takes the form of syrup, added after production, or integrated into the distillation process.
Stevens immediately recognized the advantages of CakeGuard during her studies.

"Without the presence of CakeGuard, in our trials we observed spoilage in about three days when it's humid, and in dry conditions it took about seven days," Steven says.

In trial studies conducted at Utica Energy, wet cake that had been treated with CakeGuard at a low usage rate showed increased stability to 10 to 14 days.

Longer stability was achieved with higher usage rates. Benefits of CakeGuard use are an increased shelf-life, allowing distilleries to store and sell the product for a longer period of time. Weiland says that WDG producers are able to serve more dairies and beef operations because they no longer have to empty an entire truckload at one industrial sized farm. In the past, smaller farms were never able to consume the wet cake fast enough before spoiling occurred. CakeGuard makes it possible to provide a feed that won't spoil for up to two weeks.

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