I posted most of this in another member’s thread, but it’s a bit of a rabbit hole, so I deleted it there and moved it here. I have another thread on this topic, here, but haven’t been able to get much feedback on my calculations or assumptions. That thread is pretty dense, so here is a condensed version. Many seem to be using the sap given for “soybean, fully hydrogenated” successfully when using GW 415, but when I was first contemplating using “soy wax,” I found some posts on this forum where makers reported softer or stickier than expected soap. There has also been quite a bit of uncertainty expressed about the fatty acid composition of GW 415. In my quest to determine the “real” FA profile of GW 415, I tracked down the manufacturer’s product sheet and Certificate of Analysis (COA) documents on the CandleScience.com website, here. Key information: Partially hydrogenated soybean oil Fatty acid composition (typical values per 100 g): Saturated fat 44 g trans fat 39.4 g Monounsaturated fat 16.6 g Polyunsaturated fat 0 g Iodine value: 45-55 So, what is the trans fat??? Based on research papers linked in earlier soy wax threads and some I found on my own, it’s highly likely that the trans fat is mostly elaidic acid, an unsaturated C18:1 fatty acid. If it is, the sat:unsat of GW415 is 44:56. I think that also mean that GW 415 does not contain trans versions of polyunsaturated FAs, which is good to know when calculating recipes. If you don’t want to make that leap of faith, it’s easy enough to compare the iodine value range of 45-55 for GW 415 given by the manufacturer with the iodine values given for partially and fully hydrogenated soybean oil in the soap calculators. First, as given on the Soapy Stuff website, here: “The Iodine Number indicates the amount of of unsaturated fatty acids present. Soap made with mostly unsaturated (liquid) fats will tend to have a high Iodine Number and soap made with mostly saturated (solid) fats will have a low Iodine Number.” The iodine number given in the SoapMakingFriend calculator for “soybean, fully hydrogenated” is 1 and for “soybean, 27.5% hydrogenated” is 78, both quite different from the 45-55 range for GW 415 given in the manufacturer’s COA sheets posted on the CandleScience.com website. My research, calculations, reasons for settling on an NaOH sap of .144, estimated FA profile, and the results of some of my trial runs using various sap values are given in the thread I linked above. I was more or less stumbling along at first, which probably makes it challenging to read the thread, but eventually my estimated numbers aligned well with the information available from the manufacturer. The FA percentages were determined by trial and error until I achieved the iodine value, sat:unsat ratio and percentages of saturated and unsaturated (oleic +trans) fats given by the manufacturer. The percentages I settled on are: Palmitic - 10% Stearic - 34% Oleic - 55% (this is for the oleic and elaidic acids; elaidic acid, the trans fat, is also 18:1) This FA profile looks more like lard, tallow and palm and not at all like the profiles given for the hydrogenated soybean oils given in the soap calculators. I then estimated the sap (.144) using this FA profile and by substituting stearic, palmitic and oleic acids in as proxies for the triglycerides. The estimated sap is similar to lard (.141), palm (.142) and tallow (.143) and higher than the sap values in the calculators for unhydrogenated soybean oil, 27.5% hydrogenated and 100% hydrogenated, which are .135-.137. I recently discovered that the SoapMakingFriend calculator allows a user to add a custom oil to the oil list. I used that feature to add “GW 415” with a KOH sap of .202, the FA percentages I calculated and an average iodine value of 50 based on the range given by the manufacturer. SMFriend calculates the NaOH from a KOH sap. A KOH sap of .202 returns a NaOH sap of .144. If the “real” sap is close to what I calculated, using a lower sap will result in more SF.