Premixed Lye- losing effectiveness?

Soapmaking Forum

Help Support Soapmaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Joined
Oct 20, 2019
Messages
533
Reaction score
1,533
Location
Seattle. WA USA
Sadly I've been occupied and haven't made soap in months. I don't think I've made anything since January. I had mixed up some lye water in containers and sealed them but didn't use it until yesterday when I decided I was sick of seeing those two containers on my shelf and since I'm packing up stuff I didn't really want to risk moving two containers of lye water in my move so I made soap. I found that when I made the two batches of soap with the premixed lye that they both took awhile to come to trace and the second batch that I made with the lavender EO that I always use came out extremely soft. The other batch was a charcoal and peppermint soap. I used my usual recipe, goat milk to replace the water discount I used to dissolve the lye, and I soaped at 88*, and I added sodium lactate. I also noticed that it seemed to create a lot of bubbles when I stick blended the soap. I burped the stick blender and tapped it but when I started mixing it there were millions of little bubbles in the soap. I'm not overly worried about the bubbles although the bars aren't as smooth looking as I wanted but it's fine as the soap is a custom request and I could give him bars that looked like poop and he'd use it. The second is also a custom request and the pour came out quite lovely. I was practicing my ombre technique and it came out nice but the soap is sooo soft. It's sticky and when I cut it the soap cutter wires left grooves that are not all that appealing. Thankfully again the customer that is buying this batch doesn't care about cosmetic looks but I'd like to avoid this in the future. I only cut one loaf so I'm going to wait a few days before I cut the second one and see if it makes any difference. Has anyone used lye that was mixed up months ago and had it behave weirdly in the end product?
 
Masterbatches can lose their efficacy to some degree, as the lye reacts with the environment (for example and if I recall correctly, the sodium hydroxide reacts with carbon in the air to form sodium carbonate) but how much so will depend on how it was sealed and stored
It was completely sealed and I weighed it before using it to make sure that there had been no evaporation. The weight was the same as when I made it (I marked the weight on the container when I made it).
 
There wouldn't have to be evaporation or even a change in weight for there to be a reaction between the lye solution and the air inside the container - I'm not saying that this was your situation, but if a container of lye solution is only half full and completely sealed, that is a lot of air for the solution to react with
 
I would say there was probably about 1/4 inch of air at the top. Good to know. It made soap so I'm not super concerned about it, the bars will probably just be extra super fatted. I don't think I'm going to store lye like that again. I will just have to get off my butt and make soap with whatever I mix up. Life has just been so...hectic lately. I should have started making soap months ago for the holiday season but it just seems life gets in the way.
 
Masterbatches can lose their efficacy to some degree, as the lye reacts with the environment (for example and if I recall correctly, the sodium hydroxide reacts with carbon in the air to form sodium carbonate) but how much so will depend on how it was sealed and stored
Slightly off topic, but I'm curious if there's any specific container that's suitable for storing premixed lye? I've always considered it, but now with my weekly soaping it's almost necessary.
 
Slightly off topic, but I'm curious if there's any specific container that's suitable for storing premixed lye? I've always considered it, but now with my weekly soaping it's almost necessary.
Old laundry detergent bottles are one idea. I would do a forum search on it, though
 
Slightly off topic, but I'm curious if there's any specific container that's suitable for storing premixed lye? I've always considered it, but now with my weekly soaping it's almost necessary.
I use recycled lunch meat containers for my premixed lye. The longest time I've stored them was about 6wks
 
I premix my lye all the time in a 50/50 solution using distilled water, and so far, I have not had any trouble soaping with it, even when as an experiment I waited over a year to use it. Maybe it was the 'luck of the Irish', but nothing out of the ordinary happened when I soaped with it.

I store mine in a repurposed, well cleaned/rinsed liquid laundry detergent bottle with a no-drip spout, made of HDPE #2 plastic, and I mix my solution beforehand in a large Rubbermaid pitcher made of PP #5 plastic. Just a heads-up: it sure seems to take nearly a gazillion rinses to clean all the residual laundry soap out of the detergent bottle beforehand, so fair warning. My lye solution doesn't go in unless there's not even a single little soapy detergent bubble left. lol

IMG_5462LyeContainers640.JPG



IrishLass
 
Slightly off topic, but I'm curious if there's any specific container that's suitable for storing premixed lye? I've always considered it, but now with my weekly soaping it's almost necessary.
Just make sure the container is made of Polypropylene (recycle code #5 - US) or HDPE - High Density polyethylene (recycle code #2 - US). Either is good for masterbatch lye solution storage.

Personally, I prefer the very sturdy Essential Depot lye bottles that have child-proof caps for my mb lye solution. One perk is that they are already labled as caustic and NaOh, as well as other safety precautions, but that's only part of why I like them. The size is best for my hands, as they don't hold too much liquid for me to lift and pour.
 
Lye itself does lose effectiveness over I time, mixed or not. I had bought supplies from a retired soapmaker and the soaps I made with her lye (old) were softer than the ones I made with fresh lye. (Everything else the same).
 
In my research and the courses I've taken, it all says don't use after 14 days (2 weeks). I've never experimented with this. Has anyone else heard of the 2 week guideline?

I've never heard of the 2-week guideline, and going by my own experiences where I can go through some long stretches at time in between soap batches, that sure would be a lot of lye wasted if I followed that particular advice. I've been pre-mixing my lye for several years now, and so far, that kind of advice has proven to hold no water.....at least for me anyway. Makes me wonder if it's not just a way to get folks to buy more lye. 😜


IrishLass :)
 
Has anyone used lye that was mixed up months ago and had it behave weirdly in the end product?

I had about a half gallon of 35% left over from the previous Fall that I used a few weeks ago and didn't notice any difference or have any issues.

Part of the issue with your batter coming to trace could have been the starting temperature of the Lye Solution...the colder mine is, the longer it takes even if I try to compensate with high temp oils. And the colder the Lye Solution, the thicker it seems to be. The soft and sticky soap...hard to say really.

.
 
While cleaning out my closet recently, I found a container of lye solution that I had totally forgot about. It had to be over a year old, at least. I used it and it worked fine. I, too, store in a rinsed laundry container just like the one @IrishLass is using. I’m not sure why yours has an issue. Soap gremlins….lye gremlins🤷‍♀️Who knows??

I have never heard the 2 week guideline and can positively say, it is not true.
 
Hmm, we got an extra milk tank that had a spigot welded into it. Guess I had better take a good look at. I think it has a ball valve on it. All I remember from about 5 years ago is the milk inspector said it was a no-go for the dairy.

I have been looking for something to store MB Lye solution in and have found everything from free (recycle) to $550 for unheated lye tank at soapequipment.

Really interesting perusing the forums. My soap shed arrives around Dec 8 and then we must finish the inside of it. I plan to begin making soap in March again.
 
Please don't use that milk tank for lye solution without carefully thinking things through. The spigot has gaskets inside that won't necessarily be rated for concentrated NaOH solution. Also, if your flooring isn't rated for alkalis, any drips from that spigot can ruin the floor. Because NaOH is a highly hazardous chemical, there should be a containment system sized to hold the entire contents of the tank so a spill will be safely contained. In short, if you're making that much soap that you need to store large amounts of lye solution, it's a good idea to do due diligence.
 
I agree with @DeeAnna. Even those expensive tanks made for storing premade Lye Solution still require that you change gaskets frequently. I spilled some dry Sodium Hydroxide on my kitchen floor...thought I got it all swept up, but missed a few grains and they burnt my flooring.
 
Back
Top