Why did I get tiny little crystal looking flakes floating at the top of my lye water?

[DeeAnna]

...I've also found that if I measure out my lye pellets and leave them sit for a bit before mixing to the water, lye lint will form. I guess its pulling moisture from the air....

You're exactly right -- good observation! Solid NaOH is very efficient at absorbing water wherever it can find water.

You can see this happening in my 30-second video showing how fast NaOH can absorb water from the air. At the very end, the liquid that has grown around the NaOH granules is cloudy with sodium carbonate. Video:

 

[Ephemerella]

What a great video @DeeAnna ! Thank you so much for sharing!

 

[DeeAnna]

Awhile back, I learned any NaOH solution we'd normally use for soap making (in other words NaOH at 25% lye concentration or higher) will absorb water if left exposed to the open air. The higher the concentration, the faster the rate of absorption at a given % of relative humidity in the air, but even 25% NaOH concentration will still absorb water.

I estimated the relative humidity would have to be less than about 10% RH (like the Mojave Desert) to prevent that from happening.

That's why when people say their NaOH solution loses weight, I'm skeptical. The only time that an NaOH solution will lose weight is if the solution is really hot and creating mist (steam). After the solution cools enough so the mist stops, the solution should start to increase in weight if left exposed to the open air.

This water absorption as well as the lye lint are both good reasons to keep NaOH "under wraps" as much as possible. Not to mention keeping NaOH in a closed container is important to prevent accidents.

 

[akseattle]

So I've made the sugar boo-boo. I've absent-mindedly added it to the lye water after I added the lye, and I've lazily not fully dissolved the sugar crystals in the water before adding my lye to it. In both cases, the sugar caramelizes and gets clumpy and sinks to the bottom, and/or sticks to my stirring implement.

I've also found that if I measure out my lye pellets and leave them sit for a bit before mixing to the water, lye lint will form. I guess its pulling moisture from the air. So, now I measure out my lye only when I'm ready to mix it to my water. The last bit of dry lye in my 2lb bottles will also form lye lint when poured. I guess its from exposure to moist air.

I don't strain lye lint. But on the occasions when I did feel the need to strain my lye, I used a stainless steel kitchen spider lined with a coffee filter.

@Ephemerella , if I had seen a post like yours BEFORE I got my lye lint, I would have known what unstirred sugar looked like- so, I could have eliminated that as the culprit. When this happened, did you just continue on with the lye water and forget the sugar, or did you throw out the lye water?

 

[Ephemerella]

@akseattle, we've all been there! On the occasions that I had mishaps with sugar, I simply strained the lye and proceeded with my soap, and did not attempt to try to add sugar back in. The soap came out fine.