So my brother-in-law (great guy, btw) sent me a brew kit, ingredients, and instructions. Except the instructions never went over the whole "sanitation thing"... So, uh oh... I didn't sanitize the fermenting bucket (eek) and then my daughter even came in and threw a dish rag in the waiting 2.5 gallons of water we put the cooled Wort into (Pretty sure it was a clean rag...my wife was folding towel laundry... and the Water didnt look dirty afterwards.. had I known sanitation was such a big deal I would have begun with a fresh and sanitized bucket of water...) Are we screwed? Any predictions? Suggestions? Should I start over?? (Would be a waste wouldn't it?) Oh, and are there any "watchouts" to look for after fermentation is over? Smells? Also, is there any dangers of continuing to bottling/drink? Thanks-

3 Answers 3


Nice story! I understand your anxiety. I did the same with my first kit, although I sanitized, it was the wrong type - I used what wine makers often use, sodium metabisulphate. Also the kit was several years old. so I got very little airlock activity and in the space of a couple of weeks brewed 6 gallons of vinegar.

But yours may not turn out like that. If the kit is fresh and the yeast get off to a quick start, then you may be ok - the yeast outcompete many organisms by making the wort even more acidic and removing oxygen, and later by producing alcohol. Keep an eye on the bucket for the next 24 hours - hopefully you should see a lot of airlock activity, 3-5 bubbles per second, and a large fluffy cream cake with brown floaties on top of the beer. All of these things are good signs.

If the beer is contaminated, the most likely contaminant is acetobacter, they're on pretty much everything, and literally produce vinegar. However, a little of this in the beer may not completely ruin the beer - wheats can have a little sourness or tartness.

You'll have to be patient and wait it out and see...and make sure you santize everything that comes into contact with the chilled wort or beer from now on! Starsan and iodophor are great sanitizers, and very convenient to use.

As to drinking, there will be nothing harmful in the beer. If you like the taste, then bottle and drink. If you don't, then throw it and chalk one up to experience.

  • 1
    Even if you don't like the taste of it, if it's not straight up vinegar, it might be a good exercise to bottle a few off the batch before dumping to let them age and see what happens. Might make for a good example of what some age can do to a beer.
    – fire.eagle
    Commented Feb 14, 2012 at 16:43
  • good idea. I have to say that pride can sometimes get in the way when there's a failed batch and you just want to see the back of it, but I agree, keeping the batch can be an interesting exercise. I had a contaminated batch some months ago, and although the beer is slightly sour, it's actually quite nice, and I found myself going back for a second pint.
    – mdma
    Commented Feb 14, 2012 at 16:55
  • I constantly sanitize with sodium or potassium metabisulfite and have no problems. If you make sure your fermenting vessel is sealed then you shouldn't have a problem with vinegar as acetobacter require oxygen to create vinegar (acetic acid).
    – Mattress
    Commented Feb 20, 2012 at 15:43

Just to add to the great answer above, the only way to know is time. I am assuming you got a dry packet of US-05 or some other ale yeast in the kit? Did you rehydrate this yeast? I ask because although you don't NEED to do this (according to the packet), it would have given the yeast a 'head start' to start replicating and elbowing the acetobacter out of the way and into extinction within your fermenter. For future reference, if using dry yeast, ALWAYS rehydrate. It will help to not stress the yeast, which can be a common cause of many off-flavors.

Another best practice I've found is to: 1.) buy a big thing of starsan (it doesn't go bad, you need very little of it to mix, and it will get you through tons of brew/bottling/racking sessions); 2.) either buy, or (after HEAVILY rinsing) commandeer a spray bottle, and any time you mix up a big batch of star san (i'm usually mixing at least 2-3 gallons, as you need about a table spoon diluted with that much water), fill up the spray bottle so you can 'spot' sanitize.

Just last night, I racked an IPA to dry-hop it, and was able to hit areas where I wanted to napalm those little critters that can ruin an otherwise perfectly delicious batch of brew.

Also, I have never heard of anyone complaining of star-san flavors when it gets into the beer, so it is TRULY 'no-rinse'. This is not the case with bleach and some other solutions that will kill surface bacteria.

As far as your question re: smells, etc., I would first say that 'you will know if its bad'. However, as you haven't likely been around fermenting beer that often, I would caution you that sometimes funky smells can come from the airlock and it is perfectly fine. These can be just by-products of yeast metabolizing the sugars. However, if you get an INTENSE vinegar, rotten eggs, or really unpalatable smell, it could be infected.

Might I also recommend purchasing or borrowing a copy of "How to Brew" by John Palmer prior to/for your next brew (if you choose to do one, and let's hope you do). Great reference for ALL levels of homebrewers.

Finally, DO NOT touch this beer for at least 5 days. I know it is killing you, but what will happen will happen, and lets hope the yeast prevail. Only time will tell though, and by opening the fermenter and checking it can only introduce more bacteria into an otherwise closed environment.

Let us know how it goes, good luck!

  • 1
    Just a minor quibble: I don't put nearly as much importance into re-hydrating dry yeast. Brew Your Own magazine and Basic Brewing Radio did a collaborative experiment to test re-hydrating vs. just sprinkling, and although the sample size wasn't huge, there was basically no discernible difference in flavor between the two processes. For a 1st time brewer, there are easily 20 other things they should focus on before worrying about re-hydrating.
    – GHP
    Commented Feb 14, 2012 at 13:58
  • if the packet has sufficient yeast, then you can pitch directly. e.g. some 11.5g packets have 220 billion cells. When pitched directly you get almost a 40 percent drop in viable cells in rehydration, which gives about 130 billion - on the low side for some ales but the difference is easily made up in the exponential growth phase. The yeast that comes with kits may or may not be as fresh or have as many viable cells to begin with.
    – mdma
    Commented Feb 14, 2012 at 16:51
  • I am just quoting what Chris White says in his book, that it is a simple step when using dry yeast that can improve flavor, and that it should absolutely be done with each batch. If he has been refuted since writing it by the folks at Brewing Radio, more power to them.
    – Pietro
    Commented Feb 15, 2012 at 12:35

This answer is advice on what to do if you have a 'poor' start (and how to tell):

How was the yeast start? How many bubbles per 30 seconds on your airlock? Do you have a good krausen (as mentioned above)?

At this point (2 days in), you should be seeing a bubble every oh 1 to 5 seconds (faster is fine).

If you are bubbling slower than that, I recommend you go buy more yeast and 'reinoculate'. You'll be out about $6 or $7. Get a Wyeast smack pack from the local homebrew store if possible, not dry yeast or White Labs tube (although those are second choices). While I prefer White Labs when making a start, right now you need a rapid restart. The Wyeast smack pack (you smack it to activate the yeast) will give you a nice 'start' in the package and hopefully compete well. Also, unless it is completely off-base style-wise, I'd recommend a nice hardy yeast. American Ale or California ale are both tough and easy to get going.

You might just be chucking $6 after the now ruined kit but if you have a strong start, your yeast may outcompete the acetobacteria you probably have in there.

Don't forgot to 'aerate' (most people do this by sloshing around the container with the airlock off) the beer if you restart. Aerating later is bad but if you restart the yeast you want to oxygenate the beer to permit yeast reproduction (they need oxygen to reproduce).

Good luck!

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