Microbial Stability in Draft NA

It is near-universally agreed that NA beer packaging requires some level of microbial stabilization for both consumer safety and product quality. This consideration includes both aerobic and anaerobic beer spoilers, as well as pathogenic bacteria like E. coli and Salmonella. For this reason, the standard route for NA beer is typically packaging in cans, less often bottles, and tunnel pasteurization.

Some of the consequences of this include breweries holding off on developing NA brands until they can figure out a route to pasteurization, which may require significant capital investment for flash and tunnel pasteurizers, or logistical complications from pasteurizing off-site. In any case, it becomes a real barrier to entry in the NA space.

And where does NA draft fall in all this? Since kegs cannot currently be feasibly tunnel pasteurized, they’re left more exposed than smaller packages. Flash pasteurization or sterile filtration are still options, and, same as any other NA packaging, are good for protection up until the fill. But neither ensures protection during fill and once in the keg, not to mention after it leaves the facility and gets into the hands of distributors and, later, bars and taprooms, where hygienic practices are varied at best.

This concern is more than theoretical. Rachon et al. (2026) surveyed 90 draft NA samples from the US, Belgium, UK, and Spain. The good news is that no sample tested showed any presence of E. coli or Salmonella. The bad news is that, while 51% were classified as good quality (under 1,000 CFU/mL spoilage bacteria), 32% were classified as acceptable (1,000-10,000 CFU/mL) and 17% were classified as low quality (over 10,000 CFU/mL). And the low quality samples weren’t clustered at the threshold either. They ranged from just over 10,000 up to 2.4 million CFU/mL.

They then performed a separate challenge test, inoculating cans of NA beer with E. coli and Salmonella at various levels of CO2, with pH held constant. Pathogens were inactivated within two weeks at 2.8 v/v of CO2. At 1.9 v/v they couldn't grow, but inactivation was slow enough that viable cells persisted at one month. At 1.2 v/v, growth began to appear, but only in samples with added sugar. Growth appeared across most variants at 0.8-1.0 v/v.

It’s worth noting that in a similar previous study (Rachon et al. 2024), a field survey found two opportunistic pathogens in kegged NA beers, Cupriavidus gilardii and Sphingomonas paucimobilis. They aren’t the usual suspects, but real organisms of concern nonetheless. C. gilardii is classified as a hazard group 2 organism in the UK.

The 2026 challenge test only tracked E. coli and Salmonella though, and says nothing about the spoilage organisms behind the 17% low quality figure from the NA draft samples. This is one of the first studies to put actual numbers on carbonation as a microbial hurdle in NA beer. While CO2 does quantifiable work against pathogens, we don’t actually know yet if it does the same against spoilage bacteria, especially since many spoilage organisms tolerate or favor low- and no-oxygen environments.

Kegs remain unpasteurizable, and carbonation’s role against spoilage organisms is still unproven. We can control pH of the beer, but it isn’t a standalone fix. One of the remaining levers getting attention right now is additive-based solutions.

This itself is complicated. Many consumers distrust conventional preservatives like potassium sorbate and sodium benzoate, so much so that Whole Foods bans both outright, along with a long list of other synthetic preservatives. While effective, and still a real option for micro-stability, these ingredients are often eschewed based on consumer perception and preference.

There are some newer kids on the block disrupting the preservative paradigm. Chiber™ (Chinova Bioworks) is a chitosan derived from white button mushrooms, while Nagardo® (LANXESS, the same company behind Velcorin) is a glycolipid derived from the sweet osmanthus ear mushroom. Both are fungal-derived and work by disrupting microbial cell membranes. Both have FDA GRAS clearance for beverage use, though the specifics differ.

The published data is still catching up. Neither product has independent, peer-reviewed data in finished beer. The existing studies use adjacent matrices or model systems like iced tea, juice, dairy, or malt-based solutions. The results vary by organism in every case, and nothing has been tested in a draft NA system. Extrapolating from these results to kegged NA beer is an assumption rather than a finding.

Process and recipe considerations are all tools brewers can use to mitigate microbial spoilage in kegs. Hygiene at the tap and in draft lines is out of our hands, but things like pH, carbonation, and residual extract can be set before the keg leaves the facility (a separate 2026 UK survey of draft NA beer found the worst performers tracked with higher gravity and pH). Alternative keg or dispensing systems (KeyKeg, NexDraft, Re-draft) are a whole other can of worms outside of the scope of this piece. The biggest gap in traditional NA draft is still the inability to pasteurize kegs, which would be one more control on the brewery side. If anyone ever figures that out, it’d be a big step forward.