From: Coral Clark (coralc@raft.net)
Date: Mon Dec 20 2004 - 13:54:31 PST
From: "Coral Clark" <coralc@raft.net> Subject: RE: pinhole Practical Lab Questions Date: Mon, 20 Dec 2004 13:54:31 -0800 Message-ID: <6160E3BC7B503E49A3B2CB3DC2EEB9FD0156D6@mailsrv1.raftnet.net>
Interesting soap questions. I have made soap quite a few times, both at home
and in a classroom setting, and the product is always slightly mushy (soft)
before it cures for at least a couple weeks. I have always had the best
luck with lard and coconut oil, personally. Of the many "crafters" recipes
that I have found, none call for salt; and all of the "chemistry lab"
recipes that I found call for it. It might have something to do with the
use of shortening as the fat of choice, but I am unsure. Crafter's books
tend to not recommend pure veggie shortening. Rendering animal fat
traditionally calls for boiling meat/fat scraps in salt water, which helps
it solidify. Another possibility might be the higher boing point for salt
water. I have generally done cold-process soaps, which do not require
boiling, but only warming to about 120 degrees F. At no point have I ever
used a fridge in the curing process. There are a few cold-process recipes
on the link below that are small batch, which are difficult to find as
commonly found recipes call for a 12 oz. can of lye and about 5 lbs. of fat.
yuck. As there are so many methods and variables, comparisons and/or inquiry
lessons seem like good possibilities. Note: I have never had great success
with the "blender method", if you run across that anywhere.
http://www.homeschoolzone.com/pp/crafts/soap.htm
The following site has a link to a lye calculator.
http://www.soapcrafters.com/recipes_scratch.htm
happy soaping,
Coral
From: pinhole@exploratorium.edu [mailto:pinhole@exploratorium.edu]On
Behalf Of Dylan Golden
Sent: Monday, December 20, 2004 12:48 PM
To: Pinhole Listserv
Subject: pinhole Practical Lab Questions
1) In an acid/base soap making lab most recipes call for the addition of
very highly concentrated NaOH solution to vegetable shortening. Has anyone
obtained a good soap product using less concentrated NaOH (say 1M) and then
adding more of the solution to the fat? The solution takes longer to come
to a boil and the water can be poured off although our reduced concentration
product was a little mushy. The recipe also calls for the addition of salt
water. Any explanation? Sodium is needed in the saponification reaction
but in comes from NaOH and the refrigerated product is not at risk of
freezing.
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