The Faulty Valve: When pervasive contamination threatens brewery operations

This icon shows a brewing tank partially transformed into a stick-figure character. The character looks surprised and as if he has a question, with a finger up in the air as if getting ready to ask.
This fermenter wants to know what to do when CIP doesn’t stop repeated microbial contaminations!

How spoilage can put your whole operation at risk

What do you do when you know you have a contamination issue, but can’t find the source? Especially when the clock is ticking and spoilage is threatening to put you out of business?

At BioMire, we have the privilege of working with customers to deal with difficult microbial problems, and because we’re here to help industries and the people who run them, I want to start sharing some of their stories with you.

In this case, a brewer reached out to us at a make-or-break moment, when his operation was at risk of collapse and he needed help getting to the bottom of a contamination problem.

For months, a pale film appeared during the fermentation stage, systematically spoiling every batch he tried to brew. A lab analysis confirmed lactic acid bacteria contamination. So, like any good brewer, he did what he knew had to be done:

  • A total top-to-bottom cleaning
  • A boost to his hygiene plan
  • New disinfectants, equipment updates, hygienic caps and other sanitary clothing
  • Closure of the brewery to visitors during brewing

But nothing worked. The film kept appearing, batches were thrown out, and his accounts dropped further and further into the red. Again and again he cleaned, but the film wouldn’t stop spoiling his brews.

How to act fast when a microbial contaminant can be hiding anywhere?

Lactic acid bacteria can be introduced via raw materials or even just the air. Part of the problem, though, is that once it has infiltrated a brewery, it might be found pretty much anywhere in the process.

When the brewer reached out to us, he needed to run an investigation to find the contamination source, but fast, before it was too late for his business. We shipped him a box of nomad test kits within three days and started forming a plan he could put into action as soon as they arrived.

Knowing that lactic acid bacteria propagate slowly, we had a hunch that we should look at what was happening before the fermenter, even if the film was appearing there.

Gathering the right data to find a culprit

We guided our brewer through an investigation that started with an analysis of the situation before Cleaning In Place (CIP).

The idea was to focus our controls on equipment rinse water, both before and after CIP (though initial readings revealed high microbial levels in the production water, which made it necessary to boil and cool before checks).    

Checking contamination levels before and after every critical instant and piece of equipment – the whirlpool, heat exchanger, hoses and tanks – we looked to find the least sanitary points in the process and made a map of contaminations that CIP had to treat.

Then it was time to do a full CIP routine (after a refresher training) and rerun testing: all the numbers came back low, except after one particular valve. Aha!

After taking apart the valve and observing, we saw what appeared to be a faulty seal, blocking sanitants from making contact with parts of the valve when it is in the open position.

After replacing the problematic seal and sterilising the valve, we ran the process and tested again.

The contamination levels stayed low, the white film didn’t appear, and the batch was good.

Now the brewer is back to brewing with confidence.

Lessons in microbial risk management

As with every situation we deal with, we ended up taking important learning with us, as did our brewer:

Don’t get tricked by the source of the problem

  • Lactic acid bacteria can come from anywhere, but in this situation the problem was a weakness in hygiene caused by a faulty piece of equipment.

Run a diagnostic before taking action

  • 4 months of trial and error, even though based on good instincts and best practices, almost put an end to this brewery.
  • Just 10 days passed between the brewer’s first telephone call to BioMire and the discovery of the valve at the source of the problem. A few hours later, the situation was back under control.

Monitoring beats damage control

  • Every beer batch thrown out represents lost sales, wasted operating costs, strained relationships with customers, and stress.
  • The brewer in question now uses nomad test kits to run periodic testing, so he can keep an eye on microbial levels in his process, rather than put everything at risk again.

Preventative maintenance is also part of the solution

  • Performing maintenance on critical equipment before a resiliant microbial colony takes hold is critical, as for example with brewers who fully sanitize o-rings on a regular schedule, can save you time and pain
  • Cleaning equipment needs to be clean to be effective! It may seem obvious, but we have examples where experienced brewers discovered they were using dirty brushes and mops, creating a worse situation than before their started cleaning. And dirt removal may not be enough…

We hope these tips will help you get ahead of microbial contamination in your brewery, or wherever you are trying to avoid spoilage.

In the end, for us working at BioMire, the human element of managing microbial risk is the most meaningful aspect of what we do.

Even highly skilled professionals can run into problems they can’t solve on their own.

We are very happy that in this case we could help get this particular brewery back into operation before it was too late.  

Have you run into a situation where you knew the problem you were dealing with but couldn’t find its source? How did you investigate? Let us know!