FANTASTICAL INF e CTIONS

AND WH ere TO FIND TH em

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 W e G e T r ID 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.

To eradicate beerstone, via Birko Corp:

▶ Rinse out beer and yeast with ambient temperature water.

▶ Use a one to two ounce per gallon phosphoric/nitric acid mixture (maximum 140 degrees Fahrenheit) for 1530 minutes.

▶ Do not rinse.

▶ Use a non-caustic alkaline cleaner at one to two ounces per gallon of warm (120-140 degrees) to start. (FiveStar PBW, or Powdered Brewery Wash, as examples.) CIP for 15 to 30 minutes depending on conditions.

▶ Rinse with ambient temperature water until the pH of the rinse water is neutral (same pH as the tap water coming in).

When dealing with an infection, focus on eliminating the current infection by doing the full Birko Method on every single tank that touches your fermentation: Mash tun, heat exchanger, fermenters, etc. Every part of your equipment that can be stripped down and broken into pieces should be. If it can fit into a triple-bay sink set up, each piece should be scrubbed down with a non-caustic alkaline cleaner until no visible biofilm is present, followed by citric acid and finally a high-foaming sanitizer.

After that, whatever can fit into an autoclave — a $150 InstaPot makes an affordable in-process autoclave for sanitization — should be autoclaved before it comes into contact within your production space.

After eliminating the current infection, it’s

Citations

Vestby LK, Grønseth T, Simm R, Nesse LL. Bacterial Biofilm and its Role in the Pathogenesis of Disease. Antibiotics (Basel). 2020 Feb 3;9(2):59. doi: 10.3390/antibiotics9020059. PMID: 32028684; PMCID: PMC7167820.

Prinzi, Andrea Ph.D., MPH, SM(ASCP) , and Rodney E. Rohde. "The Role of Bacterial Biofilms in Antimicrobial Resistance." American Society for Microbiology, 6 Mar. 2023, asm.org/ Articles/2023/March/The-Role-of-BacterialBiofilms-in-Antimicrobial-Re.

Oliver, Garrett. The Oxford Companion to Beer. Oxford University Press, 2011.

Johnson, Dana. “How to Remove Beerstone.” Birko Corp., 29 Aug. 2017, www.birkocorp.com/ resources/blog/how-to-remove-beerstone/.

Any place where there are nooks and crannies, there are safe harbors for infections. Like on this plate chiller plate — Soils build up over time where the caustic and acid circulation can't reach during daily cleaning. Equipment should routinely be taken apart to ensure proper cleanliness and sanitation.

important to switch your cleaning and CIP process.

I recommend keeping a waterfall rotation going: One fermentation in the vessel, do the Birko Method. The next fermentation in the same vessel, do the classic CIP routine of caustic to acid to sani. The third fermentation in the same vessel, use the non caustic alkaline cleaner to citric to sani.

Like other bacteria that enter our body, specific strains can build resistance within your production space, so focusing on switching things up is key to reducing buildup and focusing on ensuring no build up in the future.

For additional protection, do a full triplebay-sink cleaning cycle on all equipment and then autoclave the tri-clamps and gaskets at the end of the day.

ALWAYS B e VIGILANT

A big challenge with any major food production process is knowing when you’ve adequately met the sanitary demands of your products. Obviously this is no different when it comes to your fermentations. Because distillation is a game of concentration, it really is a game of crap in, crap out.

But by taking time to be thoughtful, ensuring you’re following procedures from batch to batch, and utilizing the tools in your toolbelt to double-check your work, you can significantly reduce the chances of infections taking hold and creating less-than-spectacular spirits.

It causes its own headaches. How many times have we said, "It has to be X?” But it wasn’t… Each time you think you've finally nailed it down, the answer quickly squeaks away. But, that's science. Operate with the best information you have available and move forward eliminating variables until proven correct. Or if proven incorrect, then check that off the list and approach the next likely answer.

Rinse, repeat.

Destilador Enmascarado (Masked Distiller) is an occasional column dedicated to sharing knowledge and solutions to common challenges within the distilling industry that are maybe just a bit too taboo to publicly attach your name to. Written under a pseudonym, but full of good info. We’ve all dealt with it, now let’s talk about it! Is there something we don’t talk about that we should? Email info@artisanspiritmag.com and let us know.

Written by Doug Hall