Lye solution temp - CP

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Well-Known Member
Jul 28, 2008
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Eden, Utah
If I am not adding any sort of EO, FO, herbs, Etc, is there a reason to wait until the lye is down to a lower temp, say 110 or so? Or am I able to combine the solution with the oils at a higher temp, which (in my pea brain :wink: ) would seem to get the sap process cruising.

I honestly have never once checked the temp of my lye solution. I mix my lye & let it sit in the sink while I organise my oils & anything else I'm using. Once I have every thing together, I add the lye to the oils and off I go. The only exception to this is when I make a milk & honey soap, I have to refridgerate the lye to cool it right down, otherwise my soap overheats & separates. (it also goes in the fridge overnight)

Generally, the cooler you have your oils and your lye, the slower it moves to trace, so if you are wanting time to play with colour, fragrance, etc, soaping with cooler oils & lye can be better.

Alternatively, you can soap warmer and hand stir to trace. I've been doing this lately, and find that it doesn't really take much longer, and I have more control over the whole process. I actually find thin trace instead of stickblending straight past it :oops:

So, to make a long answer short, I don't believe that the temp of your lye really makes a huge difference, generally. Try it and see :lol:
Ly solutions temp?....CP

Well, I may technically be still a newbie, but I know why I sometimes like to stop the process at thin trace. That is where you want your mixture to be if you are going to do a swirl with different colors. At least, that is why I sometimes stop the clock there. Sometimes, I just can't seem to get past thin trace and I just go ahead and pour into the mold....using one I know does not leak at thin soap comes out just as nice!
The only time I'm picky about temps is when I'm using a high percentage of PKO, or fats with a high stearic acid content. If I soap too cool with them they tend to re-solidify on me sometime during the soaping process and I end up with ricing and/or little white spots in my finished bars. The soap is still good, but not very aesthetically pleasing to the eye. For those kinds of soaps, I soap when my oils reach 120 degrees F, and when my lye is somewhere between 95 to 100 degrees F.

I just had an interesting experience mixing at higher temps. Usually I mix the lye/water into oils at anywhere between 100 & 110 degrees F & the oil pot is warm to the touch.

This week-end I mixed at 120. I was using a liquid ultramarine purple colorant that I've used 3 times to get a nice lavender color. This time, I mixed the color in, it was the perfect lavender I've always gotten, poured & set aside.

I continued on to my next batch. When I moved my newly poured batched next to the was lavender batch, the lavender batch had turned a very pretty PINK!!! Everything was exactly the same as 3 previous lavender batches with the exception of the hotter mixing temp.

This morning, it was a purply mauve color - still not lavender.

So, I conclude. :D Hotter mixing temps can contribute to morphining colors.
I've had weird things happen with UM Violet turning different colors while going through saponification and cure, too. Don't hang up the towel yet, though. I've had my UM Violet soap finally reach the shade I was hoping for within a couple of weeks down the road from pour.

IrishLass :)
Actually, I've gotten to where I premix my lye the night before, and when the solid fats are about 90% melted, I go for it.
Wow, I'm surprise to hear Becky never checks her lye temp. I would think that is a recipe for disaster! But if it works, that's great.

As for me, I always check my lye and settle with 100 - 110 degrees F. I find that it forms a thin trace and I just pour anyway like reallyrita. So far, so good. :)
Thanks for all of the input, but yet another question! :lol:

When you premix the lye the night before, I was under the impression that you needed to heat to saponify and trace the oils. Once you add oils to a cooled down lye solution, does it heat back up for trace? Do you also pour at a thinner trace?

I might be analyzing this too much, but sometimes I just have to know! :wink:

You all are great, and I can't believe how much I have learned in such a short time! THANKS!!!
Sometimes my lye is mixed a couple weeks before, it's not the temperature of the lye/water that heats up the oils, it's the chemical reaction that causes the heat!

My lye is usually around 75 - cooler in the winter. But my cold soap goes into full gel ever time.
Deda said:
Sometimes my lye is mixed a couple weeks before, it's not the temperature of the lye/water that heats up the oils, it's the chemical reaction that causes the heat!

My lye is usually around 75 - cooler in the winter. But my cold soap goes into full gel ever time.

Duh. I knew that! Must have had a brain fart! Thanks.
I have craft fairs coming up in a couple months so, I've been having to do several batches back-to-back & my temps are getting real close to room temp. I haven't had any problems soaping at these lower temps. In fact, I'm liking it, 'cause I can do batch after batch without having to wait for things to cool down.

It helps that the recipe I'm using doesn't have any hard butters that have to be melted down, though. 8)

I have NOT had any accelerated tracing or seizes at these lower temps.

There's a thread on pre-mixing here which is relevant to this discussion: ... php?t=5144

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