Puritan Medical Products Blog

How to Swab Surfaces for Beer Contamination: Beer Testing Guide

Written by Elaine Seavey Maliff | Aug 15, 2024 1:34:06 PM

Restaurants and breweries take food safety very seriously – and this includes beer contamination. But hobbyist home brewers and new micro brewers may not have access to the food safety and surface testing information they need to ensure they’re brewing clean beer. 

Sanitation is essential to producing the best product possible, and with breweries popping up at rapid pace around the country, these small-scale breweries are ramping up their production, and in turn, their sanitation programs.

In fact, sanitation is so vital that, “most brewers spend their first several months of their career just learning to clean, before they are ever trusted with brewing,” said Jim Kuhr, brewmaster and director of brewery operations and for F.X. Matt Brewing Company, the brewery behind the popular Saranac brand.

So, have you ever wondered what goes into preventing surface and beer contamination at breweries? Let’s find out.

Introduction to Surface Sampling to Protect Against Beer Contamination

Beer quality control tests in breweries are a cornerstone of ensuring the production of safe and high-quality beer. This process involves identifying and quantifying the microorganisms present in beer and its production environment. 

Before we get into the details for testing, let’s take a closer look at the common causes of contamination.

Commons Causes of Beer Contamination in Breweries

During the grain malting process, cereal grains are germinated and dried. The starches are then converted to sugars, which are gradually consumed by yeast as the beer ferments and becomes alcoholic.

Not surprisingly, this high-sugar environment is extremely attractive to bacteria, which may thrive and multiply; potentially ruining a batch, or worse, contributing to the contamination of an entire facility. Common microbes tested for include lactobacillus, pediococcus, and wild yeast, all of which can spoil beer and affect its flavor and safety.

If you’re a small-scale brewer, that kind of contamination can end up costing you thousands of dollars in unusable products.

Types of Beer Quality Control Tests

There are three common types of quality control tests that breweries can implement to ensure their products meet the highest standards:

  • Beer Microbiology Testing: Detects and identifies harmful microorganisms.
  • Sensory Analysis: Involves tasting the beer to ensure flavor consistency.
  • Chemical Analysis: Measures parameters like pH, alcohol content, and carbonation levels.

Each type of test serves its own purpose - but for the sake of this article, we’ll be focusing on microbiological testing.

6 Best Practices for Beer Quality Control Tests

To ensure the highest standards of hygiene and quality in your brewery, it is crucial to implement best practices for environmental testing. Here are some key steps and guidelines to follow:

1. Develop a Comprehensive Surface Testing Plan

Determine which areas in your brewery are most susceptible to contamination. This typically includes equipment surfaces, fermentation tanks, bottling lines, and any area where beer is exposed to the environment. Additionally, establish a regular testing schedule that aligns with your brewing cycles and production schedule. Testing should be frequent enough to detect potential contamination before it affects your product.

2. Use Appropriate Testing Methods

Utilizing swab tests to collect samples from surfaces and equipment is your best bet when it comes to testing protocols. Swabs should be used to collect samples from areas that are difficult to clean and those that come in direct contact with your product. In addition to swabs, conducting air samples to detect airborne contaminants in critical areas such as the fermentation room and bottling area is critical. Most importantly, regularly test your water supply for contaminants, as water is a major ingredient in beer.

3. Employ the Right Tools and Materials

Use sterile swabs specifically designed for environmental testing in food and beverage production, and ensure your transport medium preserves the integrity of your samples during transportation to the lab. Consider using foam-tipped swabs for their high sample recovery rates (we’ll get deeper into this in a bit!) And, of course, ensure that all of your people wear the appropriate personal protective equipment (known as PPE) to prevent contamination of the samples.

4. Train Your Staff on How to Conduct Beer Quality Control Tests

Train your staff on proper sampling techniques to ensure consistency and accuracy. This includes how to handle swabs, the correct way to swab surfaces, and how to avoid contamination. Emphasize the importance of personal hygiene and the use of PPE during sampling.

5. Document and Track Results

Maintain detailed records of all test results, including the date, collection location, and type of test performed. This helps in tracking trends and identifying recurring issues. Regularly review and analyze test data to identify potential contamination sources and implement corrective actions.

And if you find an issue…

6. Implement Corrective Actions

If contamination is detected, take immediate action to identify the source and address the issue. This may involve additional cleaning, equipment maintenance, or changes to your sanitation procedures. After implementing corrective actions, re-test the affected areas to ensure that the contamination has been effectively eliminated.

By following these tips, you will have a clean (and pristine) beer making environment!

How to Swab Surfaces to Avoid Beer Contamination in Breweries

One of the easiest ways to validate sanitation protocols at your home or microbrewery is to swab for bacterial growth in areas through which the beer must pass. Morebeer.com recommends "swabbing all areas which should be clean and sterile, including: cleaned-in-place fermenter hose ends, exit ports from hard piping, the plate cooler, or the filter." You may also want to consider swabbing keg interiors, filling areas, refrigerated storage, and floor drains.

Here is a step-by-step guide to help with the process:

  1. Thoroughly wash hands and forearms up to the elbow.

  2. Apply gloves or other personal protective equipment.

  3. If using a dry swab, unwrap from the packaging and add a few drops of sterile saline solution to the swab tip.

  4. If using a pre-moistened swab, unscrew the cap and carefully remove the swab, taking care not to touch the swab tip against the outside of the vial.

  5. Using firm pressure, swab an area no larger than 10 square centimeters, rotating the swab to ensure the entire tip has been exposed to the sampling area.

  6. Immediately place the swab in the transport medium and cap tightly.

  7. Label all samples and place them upright for storage.

  8. Commence testing

How to Test Beer Swab Samples for Bacteria

You have a couple of options for testing. MoreBeer.com recommends incubating the swabs for 2-6 days at 75-80 degrees; periodically checking for any growth on the swab tips.

Brewingscience.com, on the other hand, recommends streaking exposed swabs across the surface of plated media, or adding 10ml sterile wort to the transport tube and allowing it to incubate at 86 degrees for three days, and monitoring for growth. The method you choose will depend on the processing equipment you have access to. Even small production facilities need to be mindful of their food safety practices. After cleaning and sterilization, take the time to extract a few swab samples of areas that you need to ensure are sterile. Identifying a potentially compromised batch or tool could save you thousands. And the peace of mind in knowing you've got a healthy facility? That’s priceless.

What Are the Best Tools and Kits for Beer Testing?

Though every facility will implement its own sanitation and quality control procedures, Puritan Medical Products produces a range of specimen collection swabs and environmental sampling kits, which may be appropriate for surface testing in microbreweries or home production facilities.

While many home brewers tend to worry about yeast, bacteria, specifically lactobacillus bacteria, is the most common form of contamination in breweries. According to Suzanne Berens, author of “Prevent Contaminated Beer: Tips from the Pros,” unclean lines and surfaces are the most common reason bacteria will develop, and the heat exchanger has the greatest potential for harboring bacteria.

Want to learn more about using Puritan swabs for your surface sanitation validation? Contact one of our knowledgeable product specialists today.