# Why is caustic soda (NaOH) used to clean beer bottles?

I see in many blogs in the internet that cleaning bottles with $\ce{NaOH}$ is very effective. I also realize that industries use caustic soda to clean bottles. Why is caustic soda very effective at cleaning bottles? What makes it so special from other solvents which made it preferable for cleaning?

• Most organic chemistry lab use $\ce{KOH + i-PrOH}$ to clean dirty glassware. – Mathew Mahindaratne Apr 2 '18 at 21:14

Caustics such as $\ce{NaOH}$ and $\ce{KOH}$ are effective in converting insoluble fatty acids in organic fats and oils into soluble soaps in a proccess called saponification. The caustics also react with cell membranes, DNA and RNA, destroying undesired yeasts, bacteria and other microorganisms.

That said, caustics react with the glass itself, removing the surface and etching the glass. Use will weaken and damage containers.

Use caution! Caustics also destroy skin and clothing, and are particularly damaging to the eye.

• Did you mean "Caustics such as $\ce{NaOH}$ and $\ce{KOH}$ are effective" instead of "Caustics such as $\ce{NaOH}$ and $\ce{NaOH}$ are effective" ? – Avyansh Katiyar Apr 3 '18 at 3:31
• @ Avnish Kabaj , Thanks! So much for copy-&-paste. – DrMoishe Pippik Apr 4 '18 at 0:02
• Slightly etching the glass is actually a benefit if you really, really want to clean the surface of a vessel. That's why chemists often clean their lab glassware this way. – matt_black Apr 4 '18 at 10:25
• @matt_black, true, caustics are effective cleaners. However, getting rid of the last bit of alkali (or sodium silicate that forms) can be a problem for some uses. Also, I've seen caustic reagent destroy glass bottles when left too long. – DrMoishe Pippik Apr 4 '18 at 16:23

The caustics also react with glass, cell membranes, DNA and RNA, destroying undesired yeasts, bacteria and other microorganisms.

• Hi Baraka, could you elaborate on your answer? – Felipe S. S. Schneider Aug 26 '19 at 18:05
• during the cleanness of bottle in bottle washer in industry it need strong and effective disinfectant to ensure all contamination are removed when deal with contamination its about stains, bacteria, cell membranes and others undesired material, so that caustic is strong and more effective cause it react with glass effective and also removed simple and also have the ability to destroy all sources of microorganism that its my cause to select caustic to best plus coast – Baraka Magambo Aug 29 '19 at 13:25