While not nearly so old a book as Soap, it's still older, well, now that I give it some thought, I was already a high school graduate when it was published, so in the overall scheme of things, it's darn near hot off the presses. (Have you noticed all the plaid and neon the cool kids are wearing these days? It's just like when I was in high school. See, nothing's changed!)
Anyway, it remains a mostly relevant, thorough lesson in soapmaking, and not just for the beginner. It includes short overviews of successful soap businesses, how they started, and what makes their businesses unique. I appreciated the view of soapmaking before the influx of easily obtainable saponification-hardy fragrances and colorants, as well as supplies. While examining the appendix, I only recognized a couple of the companies listed, none of them being the common "big name" companies soapmakers rely on nowadays. Cavitch covers soapmaking's very basics, soap recipes, troubleshooting, some chemistry of soap (that I confess to zooming by but will read thoroughly later), and natural colorants/additives. The Natural Soap Book is probably the best resource for its time that I've come across.
To be bluntly honest, I wasn't impressed with this book after my first read, largely based on one reason. The subheading of the book is Making Herbal and Vegetable-Based Soaps, but Cavitch frequently loses her focus to bring up animal fats, usually tallow, and criticize the use. She cites skin issues that tallow "is thought" to cause, partly due to its high saturation. (Ahem. Tallow is 52% saturated, compared to 92% for coconut oil.) I got a little weary of the frequent spiel. Admittedly, I have definite views on animal fats (here is my somewhat windy explanation) and they clash with the author's philosophy. But in the end, I took a deep breath and cut her a generous amount of slack, since the book is almost 20 years old and she (and we) now knows that palm oil isn't the panacea to the animal rights and sustainability issues she thought it to be.
I was most intrigued by the essential oil chapter and decided to try out some of the essential oil blend "recipes." I've always found fragrance blending intimidating. I typically do safe, obvious blendings, like litsea and rosemary, or orange and clove, so it was fun to try some different combinations, and in my case, using both fragrance and essential oils.
Some of my favorites were Checkerberry (cassia and lavender), Summer Earth (lavender, patchouli, and vanilla), and Bar Beatriz (lavender, lemon, and rosemary). But the far and away hit for me was Summer Spice--rose, clove, and peppermint--a super fresh carnation-like floral. I had to try it out in a batch of soap.
Poor unfortunate you, dear reader, not being able to smell it. The rose fragrance has faded just slightly, but it's still absolutely lovely.
By all means, check out or buy a copy of this book. You'll get some useful information!