Regarding soap making and the use of borosilicate glass versus any other kind of glass --
"Even if you love borosilicate and think it walks on water, it's still far better to use an HDPE (high density polyethylene) or PP (polypropylene) plastic container (recycle code #2 or #5)...."
"Many people here, including me, don't recommend the use of any kind of glass, including lab quality borosilicate, for mixing or storing concentrated lye solutions or for making soap...."
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LOL,
I don't think borosillicate walks on water! It's as I said, my last chemistry class was more than 40 yrs ago, back when bakeware and measuring cups were made from borosilicate glass - thus my lean towards borosilicate. Still, borosillicate beakers and flasks are what I use for making my very, very small batches of skincare products - NEVER for making soap, and NEVER for mixing or storing strong solutions of lye. Personally, I use a stainless steel pitcher for mixing my lye and, because I'm trying to minimize my plastics footprint, a stainless steel pot to make CP soaps - for anything HP, I use a crockpot designated for soap...
"I am aware that using canning jars is not something a real chemist would think is appropriate. And I want to stress again that using any kind of glass in soap making is NOT my normal habit. But in this one situation, yes, I am making a calculated exception to this general rule.
"The only reason why I'm making this exception is some kind of clear container must be used to see the color shift in this test. "
"If I could have used plastic, I would have, but lye-safe plastics are translucent not clear and transparent plastics such as PET (polyethylene terephthalate) are not lye safe. Hence the use of clear canning jars -- they are the most reasonable option for the average person."
"This method has to be practical for the average person to do, and that goal requires a few compromises. One compromise, obviously, is the canning jars versus lab-grade borosilicate flasks. Another is doing a "titration" with dry citric acid powder rather than a standardized acid solution. I understand why these compromises would curl the hair of any competent, self-respecting chemist. But these compromises make this test a reasonable one for the average person to do."
I hope I didn't leave you or anyone else with the impression that I'm a trained chemist because I'm not... If that's the case, albeit unintentional, please accept my apology.
I'm a retired pharmacist - taking lots of chemistry classes was simply a requirement for my degree. I actually spent most of my career behind a desk, focusing on the clinical and administrative aspects within my practice setting.
I agree with you, DeeAnne.. a clear glass container is absolutely necessary in order to detect the shift in color... I don't believe it can be done any other way... I should've said and it would've been more thoughtful for me to say that I'd use borosilicate, primarily because I have it... even my measuring cups are from 45 years ago, and likely borosilicate... again, I'm sorry for sounding "absolute."
On the "bright" side of things... the topic of borosilicate vs tempered soda-lime glass caused me to look more deeply into the subject... Just this morning, I found this on the Anchor Hocking website:
Bakeware Facts
Could be the reasoning behind/justification for Anne Marie's use of glass in her soapmaking demonstrations????
Still, there exists relatively recent articles such as this August 13, 2020 article from from the NYTimes that seem to lean towards one glass type or the other, depending upon its intended use:
https://www.nytimes.com/wirecutter/blog/tempered-vs-borosilicate-glass/Or this undated article containing links to other articles about glass:
https://www.thomasnet.com/articles/plant-facility-equipment/soda-lime-glass-vs-borosilicate-glass/
It's as I said, I kinds like the nerdy stuff
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"...rather than picking up the solution to swirl over the sink, I would use either a long-handled stainless steel, or heat-resistant glass stirring rod or spoon to stir the mixture where it sits ..."
Again, the above response is just this is just a reflection of me... No matter how many times my husband has tried teaching me, I simply can't swirl anything without splashing. Once, in college, an acid I was dispensing splashed onto my clothing and almost instantaneously ate through the fabric. That experience taught me to treat chemicals with the respect they demand, a practice I'm certain every soapmaker implements... Not only that, since developing fibromyalgia, I have a tendency to drop things - I've broken so many wine glasses that I'm no longer "allowed" to have wine in the "good" glasses...
It's as if the pain in my hands prevents me from gripping onto things as much as is necessary to stop things from tumbling out of my hands! I imagine this might also be the case for people with arthritic hands, depending upon the severity. I just assumed a suggestion such as this might be helpful to others...
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Using a stirring implement isn't risk free. It introduces errors that can throw off the accuracy of a titration. A stirring implement will also raise the center of gravity of the container and increase the chance of a tip-over and spill."
I'm not sure how a stirring instrument might throw off the accuracy of the titration procedure you've provided... I would think that by recording the weight of your container PLUS your stirring instrument prior to placing anything into the container, AND keeping the stirring implement in the container during the entire process, one would still be able to determine the amount of NaOH, or KOH necessary to illicit a color change in your citric acid solution and perform the necessary calculations. Admittedly, my fibro brain doesn't work as well as it did pre-fibro... I'm sure you'll be able to clarify how this the stirring instrument could throw off the accuracy of the titration.
I think the risk of a tip-over could be mitigated by selecting a stirring instrument that wouldn't offset the center of gravity to that extreme. The stainless steel mixing spatula/spoon set I have varies in size from as short as 10.5 cm (4.13 inches) to as long as 22 cm (8.66 inches), with another six lengths between the two. I think this relatively inexpensive set is similar:
https://www.amazon.com/dp/B08JV2HB5V/ref=cm_sw_em_r_mt_imm_awdb_0cGbGb17CF1K5?_encoding=UTF8&psc=1
"I would also move the container off the scale even if I did use a stirring implement. Always move the container off the scale platform before doing any manipulations like stirring. If you don't, that's a great way to ruin a good scale."
Great reminder!!! DeeAnne, your thoroughness of thought is UBER IMPRESSIVE!!! I'm certain that all of the issues you've brought forth would have become self-evident once I actually performed the test... Once again, I thank you so very much for all your help and the food for thought you've provided... it's how I learn...
Maybe she's using vintage pyrex
