By Michael Cairns
For the Oregon Beer Growler
Does spent yeast constitute a water quality issue for Oregon streams, and a financial burden on the state’s craft breweries? A September 2014 beer blog post described how two Austin, Texas breweries faced a fee of $5000 for “improper yeast disposal.” The piece made this writer want to do a little investigation to understand whether Oregon’s brewers are in danger of also getting slapped with hefty fines.
To understand why yeast would be considered a pollutant, a very brief science lesson is in order. Yeast, along with cleaning water, spent mash and hops that remain after the brewing process is complete, is usually discharged into municipal wastewater systems. Note that in Oregon most spent grains and hops, along with the yeast, are usually sold or given to farmers for animal feed — it’s organic and very nutritious. And yeast is ‘harvested’ for reuse in many breweries. These practices limit a lot of waste discharge, but not all of it. So where does the science come in? Well, the federal Clean Water Act of 1972 regulates the discharge of pollutants to the nation’s waterways. More specifically in this case, it’s the discharge of organic materials that may contribute to biological oxygen demand, which can stimulate the growth of algae in streams, lakes and oceans. This, in turn, can lead to a decrease in dissolved oxygen, which is bad for fish and other aquatic life. High concentrations of total suspended solids that could come from breweries pose another threat to waterways and wildlife. Acidity, expressed as pH, is an additional concern. OK, enough of the science lesson.
To determine whether Oregon breweries are in danger of being fined or required to pay special fees for their discharges, I did some digging and got some of my questions answered. First, Steve Schnurbusch of the Oregon Department of Environmental Quality (DEQ) told me that there are no requirements specific to yeast effluents, nor to brewery wastewater discharges in general. He spoke of ‘loading,’ a measure of the total amounts of organic matter discharged to streams in relation to the size of any particular wastewater treatment plant from a brewery and other industrial sources. In other words, if a large brewery is located in a small community with a small treatment plant, then there could be a problem. Schnurbusch noted that the DEQ mainly regulates end-of-pipe discharges to receiving waters — for instance, from treatment plants, rather than discharges from breweries to municipal sewer systems. He suggested I should speak to city officials who operate those treatment plants.
This suggestion led me to the City of Salem, where Nitin Joshi of Salem Environmental Services reiterated some of what I had learned from the DEQ representative. The City of Salem does not have regulations specific to yeast, or even to breweries. Salem breweries are considered commercial, rather than industrial, users. Unless a particular plant, or brewery in our case, discharges more than 25,000 gallons per day, then there are no permits required. Finally, I decided to speak to a brewer to get that perspective.
Santiam Brewing’s head brewer, Jerome Goodrow, was kind enough to talk to me as he was in the process of cleaning tanks after a brew and discharging the rinse water. Like most breweries, the spent grain and hops are used for farm animal feed, and some of the yeast is harvested. He noted that the cleaning solution, or disinfectant, is quite acidic, although it’s neutralized by use of a caustic solution, thereby creating a final effluent that is nearly pH neutral. Goodrow reiterated that they do not discharge enough volume into the city’s sewer system to qualify as an industrial customer, nor do any of the other Salem breweries. There are no issues specific to yeast discharge at Santiam.
So, the bottom line based on my limited research: yeast discharge to sewer systems does not seem to be an issue in Oregon. I’m confident that Oregon’s craft brewers are attuned to the potential and are very conscientious about recycling and limiting their discharge of both wastewater and organic materials. Further investigation may find a very large brewery in a very small community where discharge could create problems with biological oxygen demand, total suspended solids or pH conditions in the receiving waters, but that doesn’t seem to be the case at this point.
By Valerie Smith
For the Oregon Beer Growler
You know from instinct how certain music and sounds make you feel — relaxed, happy and energetic. It might even evoke vivid memories. Music is diverse and exists in every culture around the world. Humans like music. Plants even respond positively to exposure to music. Studies have shown that high-frequency sounds produce more antioxidative enzymes in plants. Would it surprise you that not only do you and your plants “like” music, but beer yeast cells do too? Sounds far-fetched, but it isn’t.
Metabolomics is the study of small molecules in the cells of an organism. In 2011, metabolomics researchers from the University of Auckland (U of A) in New Zealand did a study involving music and yeast cell growth. They used the single-celled organism Saccharomyces cerevisiae (S. cerevisiae), the species of yeast used since ancient times by brewers, winemakers and bakers. These forward-thinking lab geeks tested how S. cerevisiae reacts to sound pressure waves by putting the yeast in shake flasks along with a food source -- a glucose broth with vitamins — and let it sit overnight. They then piped in high- and low-frequency sonic vibration to the rooms where the flasks were being kept. The control for the study was a silent room. The study showed that the brewer’s friend, S. cerevisiae, grew 12 percent faster with music playing. High frequency produced slightly better results than low frequency, so it seems that any music therapy for yeast will prove successful!
Michael Kora, brewmaster and owner of the soon-to-open Montavilla Brew Works, appreciates the U of A’s findings. Kora received a bachelor’s degree in jazz studies from Wayne State University in Detroit, Mich. He played and taught drums and guitar years before delving into Portland’s brewing community. Because of his background, Kora believes music’s effect on yeast makes sense. “I think since yeast are living things, they may have some sentience, maybe on some form of preliminary consciousness. At any rate, I think that music on a very fundamental level is full of vibrations, wavelength and frequency patterns. All these measurements seem to correlate on some level with the rhythm of nature and definitely the fermentation of beer and yeast-powered products.”
Kora begins with the yeast selection when building recipes for Montavilla Brew Works. According to Kora, “Yeast is the unsung hero -- they do so much work! You treat (them) like a living thing and they’ll react like that. It’s almost like they’re human in a way. If you’re good to them, keep them healthy and happy, they’ll give back to you.” He nurtures beer development with seasonal music tracks: reggae, funk and the Grateful Dead in the summer, classical and blues in the winter and everything in between at other times. Jimi Hendrix and rock play during the cleanup.
The expansive and beneficial relationship between music and yeast may have come about because of brewer intuition, superstition or other cultural influences during the millennia. Today, the U of A’s metabolomics study proves serenading developing yeast has more benefits than anyone previously recognized. So play whatever rocks your brewhouse and the yeast will love you back.
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