How do I clean my set (>30) of PET bottles? I'm dealing with dried beer and yeast residue from my previous batch. I doubt I can use hot water, since it would deform the plastic. Do I need to scrub the inside of every single bottle, or is there an easier/faster way?

  • These are small plastic bottles? If so don't scrub. Best to just soak in some oxyclean until they wash clean without scrubing. Commented Jul 7, 2016 at 16:02
  • They are an assortment of 500-700 mL bottles. I really don't need to scrub?
    – A.Yuen
    Commented Jul 7, 2016 at 16:08
  • If you scrub plastic, you'll end up with scratches. After they're scratched on the inside, you'll have lots of places for bacteria to live. If you manage to get the wrong kind of bacteria (and not get it out) it could kill you. Your best bet would be to recycle your PET bottles and use glass. Commented Jul 7, 2016 at 16:15
  • @A.Yuen you run the risk of scratching them causing a place for bacteria to hide. Commented Jul 7, 2016 at 17:45

3 Answers 3


Warm water from the tap will not deform the bottles. If you are worried about it you can temper the water with cooler tap water. Use hot water to dissolve some oxyclean or PBW. Temper it with the cooler water. Make a big enough batch to soak the bottles in overnight and you'll be fine. No scrubbing.

I regularly do this in a large plastic bin or a large kettle.


The first trick is never to let beer and yeast dry in the bottles. Rinse them out as soon as they're empty and leave them full of water until you can clean them properly.

PBW is more more effective than percarbonate (oxyclean), but percarbonate is cheaper. In either case 60 Centigrade is the best compromise between effective cleaning and not damaging PET.


If all else fails one can use Sodium hydroxide (drain cleaner) solution, it will dissolve most organic masses and is used commercially to remove the crud at the bottom of red wine fermentation vessels. Rinse well after soaking!

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