Is there a way to make a blanking solution for my ph meter? I ran out of blanking solution and wonder if my meter is still acccurate. I'm trying to do a SAP test on my glycerin but the test is only going be as accurate as the meter. Can I make a solution using IPA and check it with phenolphtalein? Plus I think the IPA would help clean the probes.

You will need at least a 4 (acid) a 7 (neutral) and a 10 (alkaline). These are easily aquired at any place that has tropical fish tanks. Just ask for buffer solutions.

quote:

that has tropical fish tanks

Thanks,I'll check it out.

Heat,

To answer you initial question, I do not know how to make a "homemade" solution.

I can send you a few packets to get you by.

This is where you can order larger quantities. I use the Hanna solutions.

http://www.professionalequipme...jX8qICFSU65wodHBx2gA

4.01 - http://www.professionalequipme...04l/buffer-solution/
7.01 - http://www.professionalequipme...07l/buffer-solution/
10.01 - http://www.professionalequipme...10l/buffer-solution/

You probably only need the 10.01 and 7.01 but it's nice to have the 4.01 as well.

You should calibrate your meter before every use.

Heat,

Those pH solution packets are on the way.

Thanks Rick, I'm trying to do a sap test on some BDG using the microwave method. The way I see it is to keep the glycerin solution up to 200F to speed saponification ,otherwise it'll take more of the lye solution to reach saponification ,which would lead to a higher sap value and result in the bar soaps being to HOT. Am I on the right track?

Have you tried my multi-jar method?

This seems to work best for me now. It allows you to make up a range and test several SAPs at once.

You can use as many jars as you like. It's much more accurate too, because you know that each jar is fully reacted by the end of the test.

http://bdgsoaper.blogspot.com/...ap-test-knc-sap.html

You need to keep the heat up for an hour or so once you are close to your SAP number, this is to allow all of the saponifiable ingredients to get turned into soap.

I use pH paper to see "where I am" and then the meter as a final test.

Remember you need to use pH paper or a pH meter and not an indicator such as phenylethylene to give you an accurate result. This is because the pH of soap is between 9.5 and 10.5. You are shooting for a pH of 11 to be sure that you have fully saponified any saponifiable elements. Subtract one and that is your SAP. With an accurate SAP value you can ensure your soaps will not go rancid and will not be caustic hot. In addition your liquid soap will be nice and translucent.

Once you have your SAP you can use the KNC Soap Calculator to formulate a recipe for your BDG.

With an accurate SAP your soaps will just sparkle.

I read about the multi-jar method about two weeks ago,but my wife would kill me if I used the kitchen oven. I'm seriously thinking about finding a gas stove for the basement where I do my soaping .I would be able to use a double boiler for the soap and the oven for the multi-jar test. Could you use the oven to cure the soap faster,provided the temperature didn't get to high.(150 F or less)

yes, the soap will cure much quicker at 170*F.

Another idea is one of those roster ovens, you might find one of those in a garage sale pretty cheap...

1-2 hours at 170*F-180*F should fully saponify liquid or bar.