Soap making temps vary from person to person. I use around 90 - 100 and I feel it gives me a little more time with working on designs like marbles, etc. Higher and lower temps are fine as well...I think the main thing is to have both your lye solution and oil mixture at similar temps. Some people soap as high as 130 and seem to do fine.
I would disagree - I regularly soap with a room-temp oil mix and hot, just-mixed lye, and have no issues other than those created by an FO, such as accelerated trace or siezing.
I honestly think that the whole 'lye and oils must be at the exact same temp or they will create a black hole that will eat the earth' theory is an urban legend.
However, in saying that, I do believe that new CP soapers should try to keep their oils & lye to a similar temp, be it room temp, chilled or 130 degrees, for their first few batches, just to give them an idea of how it all works.
I don't mess with the thermometer either; I do the same thing as Mike, I feel the outside of the lye container. I don't like to soap above 100 .. I like a slower trace. I don't even check on the oils ... just put them on low and when they're melted and the lye has cooled to the touch I just go. Again, as with everything soapmaking, preference.
EDIT TO ADD: I'm a bit of a liar .. when I'm using yogurt, heavy cream, or goat's milk I do religiously use a thermometer and do not let the mixture get above 90F.
As you can see, there is a variety of opinions on what is ideal (in most areas of soapmaking). Your best bet for learning what works for you, is to pick one method and take notes religiously for a little while. Stick with the same method to get a feel for it and then start to make small changes...one at a time...to see what the results are.
What works for one person may not work for another. This craft seems to be evolving all the time so it really is a learning experience for everyone here. I seem to learn something new every day....I think that's what makes it so much fun.
I completely agree; one change at a time. In one of my first batches I used a new kind of FO and a new recipe. Well holy crap did that trace quickly .. was it the recipe, was it the FO, or a combination of the two? That's why it's so important that you do one thing at a time and take the notes .. it's a pain in the butt, but it pays off in the end.
When I first began doing this, I was a slave to that thermometer! It had to be 90 for one and 85 for the other... :evil: No. I like to pour around 100 degrees and now I can just about 'feel' when its time to pour. Once you get a few batches done you will get your own rhythm down and that temp gauge wont be such a big deal all. Every soapmaker eventually finds their own perfect temp! 8)
The only time I fuss over temps is when I'm soaping with high amounts of PKO and/or cocoa butter. Those 2 behave better for me when I soap them at 120 degreesF. They don't try to re-solidify on me and give my soap 'stearic spots' like they do when I soap them at lower temps.
I have to agree with cathy on the fact you should do one thing at a time! Im also new to soapmaking, and I know I drove everyone crazy with questions (eveyone shaking their head yes). but I did get good advice and learned to use a proven base and then start to add or change and only do a 1or 2lb batch ( I was doing 64oz?) till some one said.....why not just do 1lb (light bulb moment)
I master-batch my recipe and my 50% lye solution, and RTCP everything in my KitchenAid stand mixer. The room temp give the mixture plenty of time and it starts to heat up and thin as the saponification process starts, giving me plenty of time to scent, color and swirl.