Food grade lye vs technical lye

[seven]

what does it says on the bucket? is it pure sodium hydroxide and nothing else? my initial reaction is botched lye. can you call the shop and ask them about it? the >98% is normal me thinks, as there is no 100% purity for lye as far as i know (well, maybe there is, but the high grade ones).

 

[cmzaha]

Please keep in mind soap can zap for 72 hrs if being poured at a very thin trace. Also make sure you scale is correct and has new batteries. I have calibration weights for checking my scale for error. I am thinking you have other issues going on other than the lye itself. I use tech grade lye from a chemical house that is 98% on the bag. Without looking up the msds I remember it stating not less than 99% for my last bag. 50# bags cost me less than $0.94 per lb and I don't have to pay shipping. Not much point in paying the price of food grade when it is going in soap

 

[CanaDawn]

I bought some caustic soda online, dont know what kind of it, it was packed into a small (1kg bottle ) for me with only one lable "sodium hydroxide". I used it with no problems, never had a zap while testing sope the next day after making.
Then I bought some in a big bucket and as trice as cheaper at the cash&carry shop, with a lot of words about safety and uses and a number >98%. Every batch I did since is a total disaster: if I dont put it in the fridge it is overheated and leaking with lye, if I stop gelling it is ok but has zap for 2 days already.
I use my usual recipes, I checked the amount of lye in different calcs.
The last batch I made I overfat it 10% but it still zaps very very strong.
So what can be wrong? And what can I do with it?

Could be whatever the other 2% is that is causing a problem? Does it give any indication what that 2% is? It's for sure sodium hydroxide 98%?

I had trouble with a new lye causing overheating, but nothing like as bad as what you are describing, and soaping at a lower temperature of oil and lye solution worked just fine to solve it for me, but it sounds like you have another issue going on.

 

[Annavlz]

I

I think there is nothing more than caustic soda in it, as you cant have 100% spirit in the bottle. There is always will be some water from the air.
I had a thought about the scales, it is my next test to do. ( but if it weights rong it should do it with all the ingredients so proportions would be the same, I think. On the other hand with low battery it could just gone crazy)
The batch I made 3 days ago with no gelling is still zapping, but not so strong already.
I will continue to experiment and will post results later))

 

[CanaDawn]

a screwy scale won't necessarily be out by proportion, so it could definitely affect the outcome badly (rather than just making you make a slightly smaller or larger batch than planned)

 

[Annavlz]

I think I solved this problem. It seems that quality of lye can really differ from producer to producer.
This one I switched to just works longer. May be it works as usual because I always read about zapping and had never experienced it myself with the previous lye. And the first one was really good- quick and easy. But when the difference in price is so huge, 6 dollars and 14 dollars for the kg, I'm ok to wait a little bit longer than usual (for me))))
Thanks for empathy, everyone. It helped to keep going))

Resume: when you open a new bottle of lye, especially from another producer, test it on a small simple batch and give it time.