Soap going blackish-grey

[Fatima]

This is my second attempt making liquid soap, and the first one was successful. But this time around when I mixed the oil and the lye mixture together on the stove, the mixture started foaming up and then after a while started turning a disgusting grey colour. What might be the problem?

 

[BattleGnome]

What is your full recipe and method?

From your picture it can be anything from burning, ingredient quality, or mis measuring.

 

[Fatima]

What is your full recipe and method?

From your picture it can be anything from burning, ingredient quality, or mis measuring.

Olive Oil: 680g
Coconut Oil: 454g
KOH: 252 g
Water: 252g

I just washed the pot, and it looks like the KOH has eaten through the pot :/ now I am confused on what material to use for the pot

 

[Lion Of Judah]

is the pot aluminum ??? if it is then there is your problem , you having a chemical reaction with the lye

 

[The Efficacious Gentleman]

Those images certainly do look like a reaction with the pot. Even if it is stainless steel, can you tell us what sort it is? Not all are created equal and some have other metals added in which will react with lye

 

[DeeAnna]

I too think your soap pot is the problem. Please be aware -- if the pot is made of aluminum that the reaction between NaOH and aluminum releases hydrogen gas. The small amount of hydrogen being produced is not likely to be a hazard in an open environment, but I would be cautious just to be on the safe side. You may want to put the pot outside in a safe place away from people and animals and any sparks. Let the saponification process finish up, and then discard the soap.

 

[bumbleklutz]

I agree with the Gentleman and DeeAnna. It looks like a reaction with the pot. I'm guessing it might be a stainless steel clad pot with an aluminum core. The one time I had soap go grey/black was when I was using an old stainless clad pot that the steel had worn thin on and the lye was reacting with the aluminum core.

 

[Fatima]

Olive Oil: 680g
Coconut Oil: 454g
KOH: 252 g
Water: 252g

I just washed the pot, and it looks like the KOH has eaten through the pot :/ now I am confused on what material to use for the pot

\\\\\\

I too think your soap pot is the problem. Please be aware -- if the pot is made of aluminum that the reaction between NaOH and aluminum releases hydrogen gas. The small amount of hydrogen being produced is not likely to be a hazard in an open environment, but I would be cautious just to be on the safe side. You may want to put the pot outside in a safe place away from people and animals and any sparks. Let the saponification process finish up, and then discard the soap.

I switched on my exhaust fan and walked out of the kitchen. If I knew it was producing Hydrogen gas I would have placed the pot outside.

What kind of a pot would you recommend? Stainless steel?

 

[Fatima]

is the pot aluminum ??? if it is then there is your problem , you having a chemical reaction with the lye

Yeah :S the pot is aluminium, I guess the first time I made the soap it was not a problem because I used a very diluted lye solution. What material pot would you recommend

 

[shunt2011]

You should use stainless or plastic buckets with a 2 or 5 in the recycle triangle on the bottom f the bucket.

 

[DeeAnna]

I use sturdy Polyethylene or Polypropylene plastic containers -- the buckets labeled with recycle code #2 or #5 as Shari (shunt) recommended. Stainless steel will also work, but it can be tricky to get it right sometimes.

I will add that it's better to NOT turn on an electric motor near a potentially explosive gas -- electric motors can and do spark. I personally would not have used the stove vent fan, for example. I think the chance of trouble is fairly low in this particular situation, but why take the risk when the best solution is so simple -- just move the soap pot into the open air and let it do its thing.

 

[KristaY]

When making liquid soap I always do it in a crock pot that has a ceramic bowl. I've never had any problems using the crock pot.