I sanitize everything; carboy, bottles, bottle caps, tubing, funnels, etc; because I was essentially told that my beer would turn to deadly poison without it.

I accept sterilizing the lot once because I understand the complications of infections, but how anal do I have to be after that point?

  • If I wash my hands regularly do I need to sanitize them as well? Do I even need to wash regularly, between touching everything?
  • Do I need to sanitize the rim of the mouths of bottles?
  • Do I need to resanitize equipment mid-use if it's been left out for a while (minutes, not days)?
  • Can I sanitize bottles in advance?
  • If equipment is cleaned and put away clean, can it just be rinsed and used without sanitizing next brew?

Not looking for answers to only these exact questions, but the experience of long-time brewers who can offer some anecdotal evidence would be appreciated.

  • 3
    great question, I hope some of these answers debunk some myths and reinforce some great behaviours. Commented Nov 8, 2010 at 22:23
  • 2
    These stories have made my worries chill out. My first batch was last night and was so freaked out about everything being perfect I dropped a clamp on the wort. Without thinking I reached in and grabbed it. I know there is still a chance it might be off but reading these have made me feel better. Thanks. I'll keep my fingers crossed.
    – user1520
    Commented Jul 6, 2011 at 4:11

8 Answers 8


Following normal, reasonable sanitation practices (always sanitize containers and utensils immediately before use) usually keeps the risk of infection pretty low.

The greatest risk of infection after containers and utensils is simply open air. Keep your containers covered while working, even if you're just turning away for a few minutes. Keep your empty bottles inverted until you fill and cap each one.

Acetobacter is very common in household environments and can be found just about anywhere that dust settles on surfaces. If it gets into your brew, particularly after fermentation, it will convert your alcohol to vinegar.

This probably isn't a common concern, but one to keep in mind: If you make other types of fermented foods besides beer/wine/cider, you should segregate what you make where to avoid contamination. Baking bread puts yeasts into the air, but they probably won't spoil a ferment. However, creating vinegar or lactic fermination products like saurkraut involve acetobacter and other cultures that could be bad news for beer, so it would be prudent to not do these other projects in your brew room. I brew cider in the kitchen and cider vinegar & kraut in the garage.

  • 1
    All the other answers were great but this told me what I needed to know, the "why" of how a batch can be contaminated if you cut corners and one of the things you are actually protecting against in an average kitchen environment. Thanks.
    – Jarrod
    Commented Nov 29, 2010 at 17:42
  • 1
    ...interesting that you didn't accept either of the responses that were direct answers to your questions...
    – Brandon
    Commented Nov 30, 2010 at 4:26
  • 1
    The questions were just off-the-cuff examples. Maybe the title should have been phrased along the lines of "What are uncontrollable sources of contamination in an average batch?" You're answer was still great and got a +1 from me.
    – Jarrod
    Commented Nov 30, 2010 at 19:15
  • Props to danafr4: Don't get all OCD about it. Remember that people have been brewing beer and other things for thousands of years, long before sanitizers. Sanitization now is more about ensuring consistency and repeatability. Some of the modern lab-developed yeast strains are rather delicate flowers that might not fare well if there is already a stronger wild yeast in residence. As for toxicity, you'd have to do something really nasty (and stupid) to make a brew that is actually toxic. Sanitation is about avoiding the emotional loss of throwing out an unpalatable brew. :P
    – dthorpe
    Commented Jun 8, 2012 at 19:43
  • This is very interesting to me because I am just about to start both wild yeast bread making and saurkraut. Excellent! Thanks!
    – Ugly Dude
    Commented Jan 18, 2014 at 0:01

If I wash my hands regularly do I need to sanitize them as well? Do I even need to wash regularly, between touching everything?

No. As long as you're not touching the insides of bottles, fermenters etc. you should be fine.

Do I need to sanitize the rim of the mouths of bottles?

Yes. Dipping the ends of the bottles into a container of your favourite no-rinse sanitiser is all that's required.

Do I need to resanitize equipment mid-use if it's been left out for a while (minutes, not days)?

No, but I would recommend that equipment such as fermenters are sealed up if not in use even for a short time (a piece of cling wrap over the top is sufficient). This will stop dust, insects etc. getting in which could potentially cause an infection.

Can I sanitize bottles in advance?

I wouldn't recommend it. Clean in advance then sanitise with a good quality no-rinse sanitiser (e.g. Starsan, Iodophor) directly before bottling. When I bottle I setup a little production line:

  1. Sanitise CLEAN bottle with no-rinse sanitiser
  2. Dip end of bottle in no-rinse sanitiser
  3. Fill bottle
  4. Cap with cap that has been soaking in no-rinse sanitiser
  5. Repeat

If equipment is cleaned and put away clean, can it just be rinsed and used without sanitizing next brew?

Generally no but it depends on what equipment you're talking about.

Any equipment that comes into contact with the wort post-boil must be sanitised each and every time it is used (e.g. fermenters, chiller, kegs, bottles, tubes, pumps).

Any equipment that will only be in contact with pre-boil liquid or is used to boil the wort (e.g. mash tun, HLT, kettle etc.) must be cleaned thoroughly but does not require sanitising as the process of boiling the wort will kill off any nasties.

If you are doing kit brewing where there is no "post-boil" stage as such then everything should be sanitised each time you use it. Again I recommend a no-rinse sanitiser for this purpose.

  • 3
    In addition, it is typically recommended to submerge things in sanitizer for 15+ seconds. It doesn't work instantly Commented Nov 9, 2010 at 0:32
  • 5
    Yes, but these are all reiterating the mantra that new brewers, including me, follow without questioning. Is all this (and more) really necessary? What are the chances that you'll have batch-ruining contamination if, for example, you don't sanitize your bottle mouths? How common is contamination? Is it primarily in strikingly unsanitary conditions? Or is the process so delicate that someone sneezing in the next room can destroy a batch? Is it common for batches to be ruined by someone who follows the rules to the letter? Or do you have to significantly cut corners?
    – Jarrod
    Commented Nov 9, 2010 at 1:09
  • 2
    Good discussion here. One important note - you mentioned sterilizing and sanitizing. Most brewers never sterilize anything - sterilizing requires special equipment like in a doctors office, and can't generally be achieved at home. As the above people mentioned, sanitizing is necessary for anything that comes in contact with post-boil wort, but for anything like your boil kettle or spoon for stirring, just make sure they're clean, you don't want cob webs getting into your beer if you haven't used the equipment in a while.
    – user48
    Commented Nov 9, 2010 at 2:19
  • 2
    @Jarrod - Contamination is more common than you'd think. Most brewers I know (including myself) have had at least one infected batch and usually it's because they cut a corner somewhere along the line. As for the chances of contamination occurring if you skip step X, why risk it? Sanitising bottle mouths takes relatively no time compared to the rest of the brewing process. At the end of the day though it's not a delicate process, I have dogs and family members passing through my brewery and as long as I follow the basic rules and don't cut corners I never have a problem.
    – Simon
    Commented Nov 10, 2010 at 0:38
  • 1
    @spoulson - Bleach solution works, I used to use it myself. People will say that the rinsing after sanitising with bleach is a potential infection risk and this is probably true but I know plenty of people who do it without a problem. Personally I prefer the no-rinse sanitisers because I can be sure that after sanitising there is little chance of an infection being introduced before the equipment is used.
    – Simon
    Commented Nov 10, 2010 at 0:40

First off, Simon, your answer was spot-on in answering Jarrod's questions with logical, proven answers. Props.

However, Jarrod is asking for anecdotal advice, so here's mine:

In practicality, you can actually often get away with a lot of carelessness. The problem, though, is this: while the risk is low, the stakes are fairly high. I absolutely hate pouring out bad brews. (Luckily, I've never had problems with sanitation.)

I have, however, made a lot of dumb mistakes, and gotten lucky. Once, I dropped my screwdriver into the wort while it was cooling. The temperature was below 85°F, and the screwdriver, being a screwdriver, hadn't been washed in the decade I'd owned it and heavily used it. I was sure the beer was ruined, but followed one of the big rules of homebrewing: carry on. The beer turned out fine.

During my first brews, I would clean and sanitize bottles, and at the end of bottling, I would have leftover sanitized bottles that I didn't need. More than a dozen times, I filled them with beer the next time around, without resanitizing. It's probably safe, as I put the bottles into 12-pack bottles, closed the flaps, and little bug-carrying air flowed over and through them, but really, why risk it? I ended up changing my ways after I made my first gusher.

There's no need to be obsessive about hand-washing/mid-brew resanitizing things that have only touched air, but you should recognize possible contaminants (food, pets, etc.) that could ruin your day.

And there's no need to sanitize things during final cleanup, if you were considering it. Just mix up a few gallons of sanitizer on brew day, and take care of it then.

What it really comes down to is this: you're pitching 100 billion cells of yeast (or more if you make starters) into wort and your store-bought yeast is a direct competitor to anything that might have made its way into the beer incidentally. It's fairly unlikely that a few cells of bacteria or wild yeast have a fighting chance.

That said, it's by no means hard to spoil beer. Use your head, and sanitize per recommendations. After all, why risk spoilage over a few simple steps?

  • 3
    I agree. The risk is low, but with each corner you cut you increase it a little, and it would be heartbreaking to have to dump $20-$70 worth of beer (not to mention all the time you put in) down the drain.
    – Room3
    Commented Nov 24, 2010 at 13:07
  • 1
    Upvoted for the screwdriver anecdote on its own. I've had some questionable incidents with potential (though thankfully not) contamination, but that's the best story I've heard yet. Commented Nov 28, 2010 at 18:14

In general, your beer will be pretty forgiving. I once dropped a strainer into my fermenter when it was late and I was tired. So I rolled up my sleeve and grabbed it bare handed. My hands were clean but my arm wasn't. The only bad thing that happened is my arm was really sticky.

Also, to clean my bottles, I just put them in the dishwahser on that really hot setting and leave them in there until I begin filling them.

I'm usually pretty anal with my post-boil/pre-fermentation equiptment. Preboil I just worry about stuff that could contaminate the flavor like grain stuck in the mash tun's manifold. Post fermentation I clean to standards that I would use for dinner plates, except for keg lines. Keg lines are important to keep clean.

All that being said, err on the side of clean


Jarrod, you can't brew deadly poison. Though the spoiled brew might taste like poison.

PMV's comment about pre-fermentation sanitation is right-on. That's when most bacteria will get hold. And brewchez also points out correctly that the pitch rate of a good starter will take care of things because the yeast will out-compete any contaminant (and there are some) and the alcohol and hops will weaken & kill off most later.

Don't get all OCD. A few batches under your belt will begin to take the fear off. But do sanitize everything that comes in contact with the beer, including bottle rims. If I handle something that comes in contact with the beer, I'll (usually) sanitize it again since I'm touching other non-sanitary things like the kitchen counter and other brewing gear.

Maybe think of it like the person at a cafe handling food and money. If they're touching your food after handling money, then they're transferring any goo that the money has on it to your food. Gross.


First off, every batch of homebrew is contaminated. Despite using sanitizer and being careful, nothing is sterile. We might not like to admit it but there is always a critter other than brewers yeast in our beers.

That said standard soaking of everything in sanitizer post boil, as per the manufacturers instructions for your favorite sanitizer if more than adequate for clean stable home-brews. And often our yeast pitch wins out and consumes much of the sugars and such before tiny intrusions by contaminants can be detected. (All the more reason to pay close attention to proper yeast pitching rates).

Washing hands constantly, heat treating bottles, using bleach etc etc is often over kill. We need to be careful, but one can take it to far due to the fact that none of what we do (or can do) is sterile all the way through.


Maybe this is a bit late but I do not use sanitizer on the bucket I use for fermentation. I pour the hot worth right into the bucket with the coil chiller in the bucket. Same goes for the thermometer I use to find the correct pitching temp I hold it in the hot worth til it is chilled letting the heat take care of sanitizing it.

Some do worry about aerating hot worth and try to avoid splashing but according to exbeeriments on this appears not to be a big issue.

Other than this I would agree with the above posts.

Note that for the worth chiller I wash and sanitize the upper part of it as water can condense on the pipe and drip down into the worth.


That's the beautiful thing about home-brew. You cannot make toxic beer. The alcohol kills off organisms toxic to humans. You can make sour beer, nasty beer, off-flavored beer, and face wrecking IPA's, but all are still drinkable. Sanitize everything post boil on brew day and you'll be fine. Brewdog333

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