Whoa! Time to slow down, Sunrise. ALL NaOH contains some impurities due to reacting with water and carbon dioxide in the air. It's the nature of the beast.
NaOH contains some amount of water and sodium carbonate (the result of reacting with CO2) as its main impurities -- usually around 5% to 10% for the commercial grades that most soapers use. If you don't believe me, look at the certificate of analysis for Essential Depot lye -- it's typical. At that percentage, the NaOH will be solid granules or flakes. It may be clumpy but it will definitely be solid, not liquid.
And keep in mind as you use the NaOH, the purity will drop every time you open the container and expose the NaOH to fresh air. There's no preventing it -- you can only minimize the problem.
The reason why I asked Don what was on the label is that sodium hydroxide (NaOH) has many names, including being called caustic soda. But there is soda (sodium carbonate) and caustic potash (KOH) and potash (potassium carbonate). It is very easy to confuse the soda and the caustic soda. Don would not be the first person to have purchased soda and thought it was
caustic soda.
Soda (sodium carbonate) and potash will act pretty much like what Don has described -- cloudy mixture but little or no temperature rise. Properly stored sodium hydroxide and potassium hydroxide will initially make a cloudy mixture with a large temp rise and then the solution will turn clear fairly soon after mixing.
See this video for how fast NaOH absorbs water from the open air:
https://www.youtube.com/watch?v=p6m140WJ4Fw
KChaystack suggested a "dry bucket" for storing NaOH and KOH. It works really well. Here's a video of what my dry bucket looks like:
https://www.youtube.com/watch?v=zysA8Bnf2JM
To summarize the video for the dry bucket -- smaller air-tight containers of NaOH and KOH are put inside a sturdy 5- or 7-gallon plastic bucket. A commercial desiccant (water absorbent chemical) is added to the large outer bucket to remove moisture from the air around the smaller alkali containers. The bucket is kept tightly covered with its original snap-on lid or a screw-on "gamma" lid.
IMPORTANT: Do NOT put desiccant in direct contact with NaOH or KOH! The desiccant must go in the larger dry bucket OUTSIDE the alkali containers. It will NOT function properly if put directly in with the lye.
Why won't the desiccant work this way? NaOH or KOH is a powerful desiccant in its own right -- MUCH more powerful than the safer chemicals commercially sold as desiccants, such as silica gel, calcium sulfate, calcium chloride, etc. If put together in the same space, the NaOH will absorb any water out of the commercial desiccant as well as any water vapor in the space. The "official" desiccant will never be functional as long as it is in direct contact with NaOH or KOH.
So what's the point of the desiccant? The smaller containers are the first and best defense to keep the alkali inside from absorbing moisture. No container is absolutely perfect, however. The desiccant dehumidifies the air in the larger bucket to add an extra layer of protection.
A dry bucket has other important benefits. It will safely contain spills if an NaOH or KOH storage container leaks. It will discourage children and pets from getting into these chemicals. Caution: You will want to add a proven child-resistant closure for the best safety with children.
