Ask Mr. Wizard

The Necessity For Sanitizing Everything Post-Chilling


Dirk Megarry — Biwabik, Minnesota asks,

I’m enjoying your videos on BYO+ and have a follow-up question on dry hopping. I dry hop using a steel mesh ball that works really well. My method is to sterilize the ball, string, etc. before adding to the fermenter (about 4–7 days prior to kegging). Is this overkill due to the anti-microbial effect of hops (potential imparting of cleaning chemicals into the beer)? Can I skip the sanitize step as long as I ensure everything is clean?


This question is timely; the last time I brewed I was daydreaming about the necessity of sanitizing everything that touches beer after wort cooling because the use of sanitizers is relatively new in the history of beer. Sure, there was a lot of sour and spoiled beer before the introduction of modern hygienic practice, but all beer was not some sort of train wreck that was generally unenjoyable. I know there are brewers reading this thinking “duh, everyone knows that everything that even looks at wort after cooling must be sanitized!” Yet brewers add all sorts of things to beer during and after fermentation.

Dry hops, fruit, gases, finings, anti-foams, foaming agents, hop extracts, and stabilizers are a few examples. In commercial breweries, the beer is finally filled into some sort of package. The largest volume of beer is filled into bottles and cans before a bottle or can lid is applied. These last two examples are common sources of microbial contaminants because microbes grow on crowning heads and can seamers during long production runs when yeast and bacteria, either from beer or the environment, multiply and contaminate packages. In short, you ask a great question about the requirement to sanitize these doodads, let’s just call them tools, used to contain and suspend your hop ball during dry hopping.

The first opinion I will offer is that relying on the antimicrobial properties of hops to safeguard beer against spoilage is not a great strategy because beer spoils! Ergo, the bugs that spoil beer must not be particularly sensitive to hop acids. Dry hopping, however, is not typically implicated with beer spoilage because the microbes that grow on hops are not the sort that spoil beer. Call it serendipity or divine intervention, fans of dry hopping dodged a bullet with that one. However, just because hops have antimicrobial properties and are not commonly associated with beer spoilage does not lead this brewer to conclude that taking normal precautions when putting brewing tools in the fermenter should not be followed.

The long list of things above that are added to wort and beer serves as an example of ingredients and process aids that are oftentimes not chemically or thermally treated immediately, or sometimes ever, before use in the brewery. Reducing the number of items that can contaminate beer is a handy way of minimizing the number of things that can go awry when making beer. And in the modern world of brewing, the use of liquid sanitizers is an easy and effective means of accomplishing this goal.

I feel comfortable that I have provided sound and current brewing advice and can now jump into that rabbit hole about the necessity of using sanitizers. For starters, why are sanitizers the norm in commercial breweries? That’s easy; not all equipment can, with any reliable level of certainty, be freed of microbes during cleaning because of the number of hiding places where microbes can reside. Furthermore, the cleaning equipment itself can be a very effective spreader of spoilage microbes around the brewery. Typhoid Mary is infamous in medical history books, but there are few chapters devoted to the things that haunt the commercial brewer: Promiscuous pumps, haggard hoses, shredded valve seats, wonky welds, demon dead-legs, septic seals, checkered check-valves, and burly biofilms. There is a saying amongst commercial brewers that tunnel pasteurizers allow brewers to sleep at night. But what does any of this have to do with homebrewing? Well, not much because our tools are simpler, smaller, and don’t touch nearly as much beer as tools used in a commercial brewery.

The bottom line is that most of the brewing tools at home can be cleaned, rinsed, and used without any sort of chemical or thermal “kill step” because the soils that harbor spoilage bacteria and yeast can be removed by good cleaning practices. The big caveat here is that you must be thorough in your cleaning! The fun thing about experimenting with beer is that the worst thing that can happen is that a batch starts to funkify before it’s all consumed. Definitely not the end of the world. The same thing cannot be said for food handling where poor practices can directly cause severe illness. So if you decide to go au naturale and experiment with no sanitize brewing, let us know with a follow-up!

Response by Ashton Lewis.