Heat Transfer method

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So, as usual, I'm confused! I am the oh-so-lucky recipient of 2 new 5 lb. Brambleberry molds with liners! Thanks, DH!
:winner:

I purchased a new, larger mixing container from my local soaping store (Arizona Soap Supply) in anticipation of his wonderful shopping skills!

I found out that said container is MUCH to large to fit in the microwave, and being one to HATE the cleanup part of soaping, decided that today was the day to try the heat transfer method of melting my solid oils...

*sigh*

Sooooooooo - I gathered all my equipment, mixed my lye water, measured out my oils into my Big New Bucket, carried them over, stuck the stick blender in and poured my lye water - waiting with baited breath for the magic of melting to occur...

And waited...

And waited...

Hmmmm....methinks! Maybe I need to stick blend a little. Turn on said stick blender, try to break up the big chunks waiting for the HOT magic to happen....

And waited...

So, I kept stick blending, breaking up chunks and waiting for the heat to happen.
It
Just
didn't

Sooooooo....Kept stick blending until all the chunks were smooth, divided my batter ASSUMING that everything would be fine (and I still am assuming that), did my pour which was a little thicker than usual.

So - any guesses as to what I did wrong? I mean, I guess I would be surprised to find out it wasn't me, but it *might* have been...*shrugs* the placement of the moon?? lol

The hopefully-soap is sitting to hopefully-gel until tomorrow, but I really really really want this method to work!

Thanks and Happy New Year!
 
Couple questions. Did you take temps at any time? How long did you wait after making your lye solution before adding it to your oils? What percentage hard oils do you usually use? What temperature do your hard oils melt at?

Like all soaping, it’s not required to have a thermometer or temperature gun but it helps when you’re learning. Timing and knowing the little details of your recipe is what’s going to make the difference.

If I use the heat transfer method I usually stick to low melt hard oils, for me that’s coconut. I’ve successfully heat transferred for a 100% coconut oil soap, but coconut oil melts at 76F. If you have a ton of coco butter or keep your oils in the fridge you’re lye solution will have more work to do and you may run into the exact situation you’re describing. In other threads people have discussed heat transfer with no more than 50% hard oils but my numbers could be off, it’s been a while since we’ve had the topic.

That brings me to what your issue probably was: how hot was your lye solution. If I remember right, a NaOH lye solution gets to 200F because science. If you watch for the solution to clear and pour as soon as it does you’ll have better luck melting all your oils. If you wait for your lye to cool down like a proper soaper is supposed to... it gets harder to melt everything. The reaction between lye and oils does heat up but it never really gets close to that 200F mark unless you add an external heat source. You can make a double boiler but that would defeat the purpose of the heat transfer method.

if you want to be super certain that your everything is reacting you can CPOP or insulate with a heating pad. I’m not sciency enough to know if there’s some minute thing that will affect the final soap.
 
@BattleGnome - Nope, didn't take any temps at all. It was probably 5 minutes between the making of the lye solution and me pouring it in - maybe a little longer, but not by much.
I didn't even think about taking the lye solution temp - that probably would have helped!

Here's my recipe:
Olive Oil – 40%
Coconut Oil – 30%
Palm Oil – 20%
High Oleic Sunflower Oil – 5%
Castor Oil – 5%

The soap has been sitting on a heating pad and is gelling nicely, so I'm pretty sure it will be fine. I'm just undecided now whether to try the thermal thing again! lol

Thanks for your suggestions! Maybe I'll try measuring out my oils and then making the lye solution and mixing? I've never done that, but what could possibly go wrong? lol
 
Definitely measure out your oils before making the lye solution - you want to use ALL of the heat generated at the time of making the solution.

The other issue that I see with HTM is that people mistakenly pour the hot lye solution into ALL of the oils combined together, instead of pouring the lye solution into the hard oils only.

Remember, you don't need to melt the soft oils - just the hard ones. So measure out hard oils into one container, then mix the lye solution and pour it into that container. You can be measuring those liquid oils into a separate container while the melting is happening, but don't add the liquid oils until the melting is all done.

Also, if using coconut butter, be sure to grate or chop it into smaller chunks so more surface area is exposed to the hot lye water. This makes for faster melting before the heat dissipates.

Finally, don't stir too much during the melt phase because stirring (as opposed to stick-blending) releases more heat, too. Hope that helps!
 
Last edited:
@AliOop - Thanks! All good tips! I'll let you know tomorrow how it goes!

:thumbs:
Please do!

I like HTM at times, but confess that I most often melt my oils on the stove or in the microwave. Costco used to sell coconut oil in 1 gallon HDPE #5 plastic pails that happen to fit perfectly into my microwave. I miss those because scooping is so much easier from a pail than from the jars with narrow lids. But I am thankful to have saved the pails for soaping - they really are the perfect size!
 
I do nothing but HTM, summer & winter, except for goat milk soaps. Like AliOop says you melt your hard oils first then add liquid oils. No need to know temps of lye water, just pour it on hard oils as soon as it clears. I do take temps of the batch after all oils are in because in summer I may have to sit it in a cold water bath for a few minutes because I like to soap around 105 degrees. I was taught to stir all the while the hard oils were melting.
 
So, as usual, I'm confused! I am the oh-so-lucky recipient of 2 new 5 lb. Brambleberry molds with liners! Thanks, DH!
:winner:

I purchased a new, larger mixing container from my local soaping store (Arizona Soap Supply) in anticipation of his wonderful shopping skills!

I found out that said container is MUCH to large to fit in the microwave, and being one to HATE the cleanup part of soaping, decided that today was the day to try the heat transfer method of melting my solid oils...

*sigh*

Sooooooooo - I gathered all my equipment, mixed my lye water, measured out my oils into my Big New Bucket, carried them over, stuck the stick blender in and poured my lye water - waiting with baited breath for the magic of melting to occur...

And waited...

And waited...

Hmmmm....methinks! Maybe I need to stick blend a little. Turn on said stick blender, try to break up the big chunks waiting for the HOT magic to happen....

And waited...

So, I kept stick blending, breaking up chunks and waiting for the heat to happen.
It
Just
didn't

Sooooooo....Kept stick blending until all the chunks were smooth, divided my batter ASSUMING that everything would be fine (and I still am assuming that), did my pour which was a little thicker than usual.

So - any guesses as to what I did wrong? I mean, I guess I would be surprised to find out it wasn't me, but it *might* have been...*shrugs* the placement of the moon?? lol

The hopefully-soap is sitting to hopefully-gel until tomorrow, but I really really really want this method to work!

Thanks and Happy New Year!
1 gallon hdpe buckets work great for soaping, will hold your batter and fit in the micro. I can get 2 gallon buckets in my micro if I am careful, if I want to make a double batch. But normally I use 1 gallon buckets. The plus side is they are cheap you can get lids for them, so it is easy to batch up several batches at a time and they last for years. I also use them for masterbatching my lye solution.
 
i dont stir my oil and lye solution when doing this method, I do zap them a little in the micro wave first though cuz I keep my lard in the fridge--just for like 30-45 seconds
 
@cmzaha - So, where do you get these magic buckets? lol

@Marilyn Norgart - yeah, see, my big new pitcher won't fit in my microwave...
Mine were from the Costco coconut oil purchases. But you can also buy them on Amazon, or at restaurant supply stores. Best thing to do is measure the inside height of your microwave , and then you can double-check what is being sold to ensure that it will fit.
 
@Marilyn Norgart - the microwave is normal size - not tiny...lol Below is a picture of the container to give you an idea (plus some normal sized soaping ingredients to compare)

tallContainer.jpg
 
1 gallon hdpe buckets work great for soaping, will hold your batter and fit in the micro. I can get 2 gallon buckets in my micro if I am careful, if I want to make a double batch. But normally I use 1 gallon buckets. The plus side is they are cheap you can get lids for them, so it is easy to batch up several batches at a time and they last for years. I also use them for masterbatching my lye solution.
What is masterbatching your lye? I masterbatch my oils, but have never heard of this "wonder of soapmaking"
 
@Marilyn Norgart - the microwave is normal size - not tiny...lol Below is a picture of the container to give you an idea (plus some normal sized soaping ingredients to compare)

View attachment 43169

I was teasing you---I went and checked mine and my 2 gallon paint pail I got at the hwd store isnt that tall. Bummer cuz it looks like a nice pitcher
 
Something else that helps hard oils melt faster is to use a spoon or spatula to break them into smaller chunks, so that when you add the lye solution the hard oils have more surface area exposed to the lye solution. Just like in cooking, smaller meat chunks cook faster than larger meat chunks, the smaller hard oil chunks will melt faster in the lye solution than one big chunk.

When I teach soapmaking classes I use the heat transfer method, and it seems to work best to melt as much of the hard oils as possible in the lye solution before adding liquid oils. Add the liquid oils, hand stir a bit and then bring in the stick blender.
 
@Marilyn Norgart - the microwave is normal size - not tiny...lol Below is a picture of the container to give you an idea (plus some normal sized soaping ingredients to compare)

View attachment 43169
When making a smaller batch that doesn't require the big Costco HDPE pail, I use a similar pitcher to the white one on the left to melt my oils in my microwave. Works great!
 
So, yes, I used a spoon to break up the large chunks of palm oil. I had the entire bucket sitting on the blue heating pad that you see in the picture just to warm it up a little bit and the coconut oil had mostly melted, so I know it was getting warm, but - I still had the same thang! lol
I think I'm just going to the hardware store for a bucket! lol
It will take all the guess work out of life!

On the upside, I'm thoroughly enjoying my 5 pound molds! :nodding:

WetLemonRosemary.jpg
 

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