Soap Qualities Chart: What Hardness, Cleansing, Conditioning, Bubbly, Creamy, Iodine and INS Really Mean
Recipe design · Bar properties · Updated 2026-07-22
The seven numbers a soap calculator prints - hardness, cleansing, conditioning, bubbly, creamy, iodine and INS - are not measurements. They are sums of the fatty acids in your oils, weighted by how much of each oil you used. Hardness is lauric plus myristic plus palmitic plus stearic; cleansing is lauric plus myristic; conditioning is oleic plus linoleic plus linolenic plus ricinoleic; bubbly is lauric plus myristic plus ricinoleic; creamy is palmitic plus stearic plus ricinoleic.
This guide gives the commonly cited range for each property (the ones published by SoapCalc, still the reference most soapers quote), names the fatty acid that moves it, and tells you what actually goes wrong in the bar when you overshoot. It ends with a fatty-acid profile chart for the oils you are most likely to have on the shelf.
The seven soap qualities, decoded
| Property | Computed from | Cited range | Raised by | If you overshoot |
|---|---|---|---|---|
| Hardness | Lauric + myristic + palmitic + stearic (total saturated fats) | 29 to 54 | Coconut, palm, palm kernel, tallow, lard, cocoa butter, shea | Brittle bar, cracking, false trace, and a short window to cut cleanly |
| Cleansing | Lauric + myristic | 12 to 22 | Coconut and palm kernel only | Stripping. Above roughly 22 most people report tight, squeaky, itchy skin |
| Conditioning | Oleic + linoleic + linolenic + ricinoleic (total unsaturated fats) | 44 to 69 | Olive, sweet almond, avocado, sunflower, high-oleic oils, castor | Soft, slow-curing bar that dissolves fast in the dish and can develop DOS |
| Bubbly lather | Lauric + myristic + ricinoleic | 14 to 46 | Coconut, palm kernel, castor | Big loose bubbles that collapse quickly, and usually a cleansing number that came along for the ride |
| Creamy lather | Palmitic + stearic + ricinoleic | 16 to 48 | Palm, tallow, lard, cocoa butter, shea, castor | Dense low lather that some users read as "it doesn't foam", plus a fast-tracing batter |
| Iodine | Weighted average of each oil's published iodine value | 41 to 70 | Polyunsaturated oils - sunflower, safflower, hemp, grapeseed, soybean | Softness and a shorter shelf life. High-linoleic oils are the classic cause of dreaded orange spots |
| INS | Weighted average of each oil's INS, historically saponification value minus iodine value | 136 to 165 | Saturated, low-iodine fats (coconut, palm, tallow) | Nothing specific. INS is a crude composite and a poor bar fails it as often as it flags one |
Two things to hold onto. First, every one of these is a prediction computed from a fatty-acid table, not a lab result on your soap. Change your supplier and the real profile of your olive oil shifts by several points while the calculator's number does not move at all. Second, the ranges are guidelines drawn from what sells and what customers like, not physics. A 100% olive castile scores about 17 hardness and 82 conditioning - outside every range on the chart - and it has been a good soap for a thousand years.
Worked example: a 60 / 25 / 15 recipe
Take 60% olive, 25% coconut, 15% shea butter. Multiply each oil's fatty acids by its share of the batch and add the columns: lauric 12, myristic 4, palmitic 11, stearic 9, oleic 51, linoleic 8. Now run the formulas. Hardness = 12 + 4 + 11 + 9 = 36. Cleansing = 12 + 4 = 16. Conditioning = 51 + 8 = 59. Bubbly = 12 + 4 = 16. Creamy = 11 + 9 = 20. Every value lands inside its cited range, with bubbly sitting at the bottom of it. Swap 5% of the olive for castor and bubbly climbs to about 21 and creamy to about 25 without touching cleansing at all. That is the whole game.
Fatty acid profile chart for common soaping oils
| Oil or fat | Lauric | Myristic | Palmitic | Stearic | Ricinoleic | Oleic | Linoleic | Linolenic |
|---|---|---|---|---|---|---|---|---|
| Coconut oil | 48 | 16 | 10 | 3 | 0 | 7 | 2 | 0 |
| Palm kernel oil | 48 | 16 | 8 | 3 | 0 | 15 | 2 | 0 |
| Palm oil | 0 | 1 | 44 | 4 | 0 | 37 | 9 | 0 |
| Olive oil | 0 | 0 | 8-20 | 1-5 | 0 | 55-83 | 4-21 | 0-1.5 |
| Castor oil | 0 | 0 | 1 | 1 | 85-95 | 2-6 | 1-5 | 1 |
| Cocoa butter | 0 | 0 | 26 | 35 | 0 | 35 | 3 | 0 |
| Shea butter | 0 | 0 | 4 | 42 | 0 | 46 | 7 | 0 |
| Lard | 0 | 1 | 26 | 13 | 0 | 45 | 8 | trace |
| Beef tallow | 0 | 4 | 25 | 19 | 0 | 36 | 3 | 1 |
| Sunflower oil (linoleic) | 0 | 0 | 5 | 6 | 0 | 30 | 59 | 0 |
| Avocado oil | 0 | 0 | ~16 | ~2 | 0 | ~68 | ~13 | 1 |
| Sweet almond oil | 0 | 0 | ~7 | ~2 | 0 | ~69 | ~19 | trace |
Rows will not always total 100. Coconut carries roughly 11 to 19% caprylic and capric acid and palm kernel roughly 6 to 10%, and no soap calculator counts either toward a quality score even though both saponify perfectly well. Olive and castor are given as ranges because they genuinely vary that much between harvests - the International Olive Council's trade standard allows olive oil oleic anywhere from 55 to 83%, which is a swing of nearly 30 conditioning points from the same bottle label.
See all seven scores update as you move an oil. Soap Calculator renders predicted bar properties - hardness, cleansing, conditioning, bubbly, creamy, iodine and INS - for every recipe, alongside a live fatty-acid blend ribbon. Nudge coconut down two points and watch cleansing and bubbly fall together in real time, against verified SAP values for 202 oils, all of it on device. Download Soap Calculator: Lye & Recipe on the App Store.
How to actually use these numbers
- Set cleansing first. It is the one number that maps directly onto a complaint. Keep it under about 20 for a facial or sensitive-skin bar and let everything else follow.
- Treat bubbly and creamy as one lather budget. A satisfying lather is roughly bubbly plus creamy above 40. Which side it comes from is a texture choice, not a quality difference.
- Ignore INS unless nothing else is working. It compresses saponification value and iodine into one figure, and the 136 to 165 band comes from Robert S. Cavitch's The Natural Soap Book, not from any standards body. Recipes that score perfectly on INS routinely fail on cleansing.
- Watch iodine for shelf life, not feel. High-linoleic oils above roughly 15% of the batch are the usual suspects behind rancid orange spots six months in.
- Test the bar anyway. These are indices computed from a lookup table. Cure a batch, wash with it for a week, and trust your hands over the chart.
Designing the profile before you pour
The point of a qualities chart is to stop you discovering six weeks into a cure that the bar strips skin or turns to mush in the shower dish. Soap Calculator prints all seven predicted properties for every recipe you build and draws the fatty-acid blend ribbon underneath, so a change to one oil percentage shows up as movement in the profile immediately rather than in the sink later. From the same recipe you get the lye weight for NaOH or KOH, the superfat you chose, and an FDA-compliant INCI label in saponified format when the batch is done.
Frequently asked questions
What is a good INS value for soap?
The commonly cited target is 136 to 165, with 160 treated as ideal. The figure comes from Robert S. Cavitch's The Natural Soap Book rather than any governing standard, and it is a crude composite of saponification value and iodine value. Plenty of excellent recipes score outside it, so check cleansing and hardness before you let INS change anything.
What do the SoapCalc numbers mean?
They are predicted qualities computed from your oils' fatty acid profiles, not measurements of your soap. Hardness sums the saturated fatty acids, cleansing sums lauric and myristic, conditioning sums the unsaturated ones, bubbly and creamy split the lather between big bubbles and dense foam, iodine tracks unsaturation and shelf life, and INS is a composite of saponification and iodine values.
What is a good cleansing number for soap?
Between 12 and 22 is the cited range, and most makers stay at the lower end. Cleansing counts only lauric and myristic acid, which come almost entirely from coconut and palm kernel oil, so it is effectively a coconut meter. Above about 22 the bar starts feeling stripping on most skin, and facial bars are usually kept under 15.
Why is my hardness low but conditioning high?
Because they are opposite ends of the same measurement. Hardness counts saturated fatty acids and conditioning counts unsaturated ones, so they add up to roughly 100 on any normal recipe. A high-olive bar will always read low hardness and high conditioning. Add a hard fat like palm, tallow, lard or cocoa butter to move both, or extend the cure - a soft high-oleic bar firms up considerably over eight to twelve weeks.