Lye quality - floating scum in lye water???

[RogueRose]

I just switched from the Lye I purchased at the hardware store, which was packaged for drain clearing, to "food grade, high quality NaOH beads". These beads are almost 4x larger than the drain cleaner. I am also noticing that the water is not clean and clear after adding the lye and dissolving it. I end up with what looks like scum floating on top of the water and some crystals of something that seem to be floating. There also seems to be fiberous threads, very fine, in the scum.

Now to get a clear understanding of what I am saying, this isn't a thick or large amount of material in the water, just more than before (which had basically none). In 950ml of water, 336g of NaOH was dissolved and I would say there may have been a 1/4 tsp of this gunk visable. The water was also not as clear as it was with the drain cleaner.

Now what I am having a tough time understanding is that this is "food grade" while the drain cleaner should have been., most likely, technical grade, although I'm not sure if that is true in the drain cleaner product. I know for acids, technical grade vs food grade vs reagent for things like cleaning vs product reaction (pharmaceutical/food/chemical/etc), technical grade is for cleaning, like a drain cleaner. So the foodgrade should have none of this scum.

Now I did use different water. Before I used distilled and now I use de-ionized (collected from dehumidifier, triple filtered cloth/cotton/1um fiber/ then activated charcoal filtered, then heated to sterilize - so it should be pretty clean water for this process). IDK if that could be a problem or not.

Anyone else ever notice this with their lye water? Do you filter this stuf out? I double filter my lye water now which is a PITA!!!

 

[Kyra]

I too use de-ionized water for my CP soap and my 99% pure NaOH produces the same type of scum on the surface of the water. I never had perfectly clear water when dissolving my lye. I do work with a water discount, so I have a more concentrated lye solution. I never filter, never bother with it, my soaps come out perfect, I never had any issues with my soap because of it.

 

[Susie]

I once read that it was called lye lint or some such. If it bothers you, just run the lye water through a SS strainer.

 

[RogueRose]

I once read that it was called lye lint or some such. If it bothers you, just run the lye water through a SS strainer.

I love it! That is exactly what it looks like, lint from the dryer foating in water, lol!!

 

[cmzaha]

As far as I know it is the lye reacting with the air. You can either stir it in or strain it. I usually stain it but not always. There is really no reason to use food grade over the less expensive technical grade of lye in soap. If making bagels and pretzels there is a difference

 

[lionprincess00]

Like soda ash, from soapqueen.. Soda ash forms when unsaponified lye reacts with naturally occurring carbon dioxide in the air. *

So it's my opinion this is what the floaties are, unsaponified lye in water reacting with the co2 in the air. Mine has more floaties the longer I leave it alone. I stir a bit and soap with it. It does nothing strange to my final product. It is clear when I first mix, btw, and these develop as the lye water cools.

 

[Susie]

Yet another reason I use the hot NaOH water to melt my solid oils.