Lye ahead of time.

[CLMP]

I'm just wondering about mixing my lye ahead of time again. I don't think I need to master batch because I only make about 2 batches a week as a hobby I don't sell soap but what I'm wondering is if I mix my lye solution a couple of days or even a few days ahead of time will some of the water evaporate out of the container and if so how would I deal with that. I think I might of found some good containers with lids that would be good for pre mixing my lye solutions.

 

[cmzaha]

Just mark your container with your total weight after you mix your solution then reweigh before you are ready to soap. You can add back any missing liquid to bring your solution back to your original weight.

 

[CLMP]

Just mark your container with your total weight after you mix your solution then reweigh before you are ready to soap. You can add back any missing liquid to bring your solution back to your original weight.

Thank you I was wondering about that!

 

[AliOop]

If your container is tightly closed, you should not lose any water.

If it isn't tightly closed, your lye will react with the air to create "lye lint" (white flakes of soda ash). That means your lye solution isn't as strong. Adding more water to it will dilute it even further.

 

[CLMP]

Oh thank you I just have to check the lids on these containers I want to buy they have the #5pp and a screw on lid I just hope they are leek proof.

 

[Ford]

I tried master batching. Ended up with lye lint. I just mix day before or earlier day of now. I repurpos 4lb lard containers. Lids are fairly tight. Holds up to the heat.
That's 15.5 ozs lye, 27.00 ozs H2O. I put lard container in a larger container first time. Just to be safe.

 

[DeeAnna]

An NaOH solution will INCREASE in weight if you don't keep it in an airtight container. NaOH is hygroscopic, meaning it absorbs water, even if the NaOH is already dissolved in water. For the typical NaOH solutions we use for soap making, the relative humidity would have to be below about 10% (Mojave Desert dry!) to see a reduction in weight over time.

The only time you might see a reduction in weight is when you're first making an NaOH solution and there is visible mist rising from the liquid. Then there is some loss in weight. Thing is most people assume it's pure water that's lost, and that's not true -- the mist also contains sodium hydroxide. That's the reason why it's not a good idea to put your put your face over the lye container and also to use very good ventilation whenever you see visible mist rising from the liquid mixture. .

Same is true for dry NaOH -- a given amount will increase in weight over time. @Susie explained how she monitored the dry weight of her NaOH and adjusted her superfat to compensate for the loss in purity as the NaOH absorbed water with time.