FANTASTICAL INFECTIONS AND WHERE TO FIND THEM Fermentation-destroying organisms that you'll most likely encounter are Lactobacillus, Pediococcus, and wild yeasts, including Brettanomyces. Each type of infection has its own favorite nutrients, temperature range, pH range, and growth rate.
LACTOBACILLUS Lactobacillus is one of the more common fermentation infections. It's part of a group of gram-positive lactic acid bacteria (LAB) that includes pediococcus. Like the yeast we pitch for fermentation, lactobacillus consumes sugars as its main source of energy. One of the biggest issues is that lacto produces lactic acid instead of ethanol. A lacto infection also produces off-flavors and sourness and is particularly nefarious in producing diacetyl (buttered popcorn) flavors. Beer with aggressive lactobacillus infections will often become hazy. However, this indicator isn’t much help when many American distilleries utilize on-grain fermentation and distillation. Lactobacillus grows best in environments with a pH value of 4.0 to 5.0 and a temperature of approximately 85 degrees Fahrenheit.
BRETTANOMYCES Brettanomyces is a genus of yeast that is typically considered an unwanted wild yeast, although it is often purposefully used in certain styles of beer. If you’ve ever tasted a wild-fermented beverage and it has notes ranging from “earthy” to “wet horse blanket,” there’s a better-than-average chance that brett found itself into the fermentation. In spite of what some may think, brett isn’t a souring organism. Lactic acid bacteria (like lacto and pedio) are required for a true sour beer. Brett can also produce ethyl acetate (sweet/fruity) and ethyl lactate (raspberry) in larger quantities than distillers yeast. Brettanomyces can grow at temperatures as low as 50 degrees Fahrenheit and as high as 95 degrees, and can tolerate pHs as low as 2.3.
PEDIOCOCCUS Pediococcus are gram-positive lactic acid bacteria used in the production of Belgianstyle beers where additional acidity is desirable. They are native to plant material and fruits and are found in spontaneously fermented beer as the primary source of lactic acid production. It is also seen as a major source of beer contamination in commercial breweries due to its ability to adapt to and survive in beer.
Pediococcus causes high acidity and a meaty/ buttery aroma that becomes more concentrated during distillation. Pediococcus has a high tolerance to ethanol compared to other bacteria, and can range from 10 to 25 percent ABV. It tends to grow between 77 and 95 degrees Fahrenheit and cannot survive pHs higher than 8.0.
SO, HOW DO WE GET RID OF IT? Now that you’ve established that you have an infection based on your pH levels, stalled fermentations, organoleptic data points, or all of the above it’s time to eradicate it. The Birko Corp developed a specific method (which we’ll refer to as the Birko Method) that can be used to break down biofilm and beerstone buildup and that is hosting your potential infection points. This is handy to keep in your back pocket moving towards the future, because you probably won't need to maintain brewery levels of sanitization (nor will you ever really be able to if you're just not designed for that level of sanitization) if you alternate this method with the more traditional caustic, acid, sanitizer routine. I highly recommend visiting the Birko Corp website for a more in-depth focus on what beerstone is and how to combat it.
Simple cleaning methods won't work when attempting to tackle beerstone and other biofilms. Processes like the Birko Method work to soften the biofilm so the detergent can work on eradicating soil. After the non-caustic alkaline cleaning method, this biofilm was able to be cleaned off with a soft bristle brush.
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