If you are a new soap maker, you might be looking to expand your horizons and experiment with your own soap recipes. In order to do so, you will need to use a soap calculator so that you can figure out how much lye is needed to turn your oils into soap.
There are many soap calculators that you can use, but today I am focusing on SoapCalc.com since that is the one I use most often. While there are others, which are good soap calculators and might be a bit simpler to use, I find soapcalc to be the least confusing while still offering the most information about the oils I choose to use. Let me demonstrate.
So, you know by now that soap is oil, liquid (like water) and lye. This magical combination creates a chemical reaction that turns into soap. But how do you know what is a good soap recipe or a bad one? How do you predict what the soap will be like before making it? How can you tell if it is likely to cause acceleration or turn out too soft? Well, it can be a balancing act, but there are tools, such as soapcalc, that can help.
Recipe #1 – Basic Simple Mild Soap
Let’s take a look at a very basic recipe using soap calc. I have chosen only coconut, palm and olive oils for this recipe.
I chose 20% for coconut oil because, while it can make a harder and bubblier bar of soap when you use more of it (up to 25%), it does raise the “cleansing” value of the soap, and I have sensitive skin. (Cleansing = drying) (for me anyhow). While you can overcome this problem a little bit by increasing the superfat value (more on that later), I like my cleaning value to be around 14 or 15 and not any higher. Using 20% coconut oil does the trick for me. Some soap makers like to use around 25%, but this will make the cleansing value around 19 or 20 versus my favorite “14”.
If you look at the red box in the bottom of the picture, you can see that based on the oils I chose, the soap is likely to be pretty hard (38 is medium hard. Over 40 is hard. Under 36 is softer.) Because it will be hard, it will work just fine in the shower, last a good, long time, and only take a day or two in order to unmold it).
You can see that the cleansing value is 14 – just where I like it. It will be a very mild soap.
The conditioning value is 59 which is on the higher end of the range. The higher the number, the more conditioning the soap will be. So 59 is a pretty good number. It can go higher or lower, but for this illustrative purpose, I am happy with 59.
When you get to the “bubbly” and “creamy” values, however, those numbers are a lot lower than I like them. A value of 14 is not a very bubbly soap. A value of 24 is an average “creamy” value, but not very decadent.
The INS Value is good (over 140). So the overall quality of the soap would be good.
In the blue box, you can see the saturated to unsaturated fat ratio of 39:61. This tells me that the soap should not accelerate too quickly (but that can also depend on any fragrances you choose to add because they can affect this quite drastically).
So overall, this is not a bad bar of soap, but it is not as bubbly and creamy as I would like. It would be a great batch of soap for a very new soap maker to learn with because it is very simple and basic, but for me, I want more bubbly & creamy. Let’s try adding some Castor Oil.
Recipe #2 – Addition of Castor Oil
This time, let’s use the same recipe, but add some castor oil to boost the bubbly & creamy values of the soap.
Since the % column must always total 100%, I had to deduct some of the olive oil so that I could add the castor oil. I could have also deducted from the Palm or Coconut oil, but doing so would make the soap much softer. Even when deducting from the olive oil, the soap is still softer (it is now 36 vs 38 as it was before). This is because castor oil is fairly soft. However, look at how it improved the bubbly and creamy values by adding the castor oil. Castor oil has boosted the conditioning value too — it is now 61 (and it was 59 before). Also look at the saturated vs unsaturated fat ratio. It is now 37:63, so this will be a slow to trace soap (which is desirable if you will be doing fancy designs such as swirls).
Ok, overall, this is not a bad soap recipe, but 36 is a little soft for my liking. Other soap makers go as low as 30, but I have to imagine, those soaps take a long time to be ready to unmold because they are likely to be very soft. I like my values to be at least 37. So let’s see what happens if we add some more hard oils, like a butter.
Recipe #3 – Addition of Cocoa Butter
Adding butters to the recipe can increase the hardness of the soap and also add conditioning and moisturizing properties. Cocoa butter, for example is very hard. Mango Butter is medium hard. Shea butter is softer than those, but still harder than liquid oils like olive oil. For illustrative purposes, I have added cocoa butter.
As you can see by the numbers above, adding the cocoa butter has made the soap much harder. It is now a value of 40 for hardness. But it has come at the expense of a little bit of conditioning (it was 61, now it is 57). The creamy value is now higher (it was 33 now it is 37). Also the saturated to unsaturated fats ratio is now 41:59 so this recipe is more likely to get to trace faster than the previous version. If I were not going to be doing any swirls, that would be acceptable.
The INS value went from 144 to 150. All of this together tells me that the soap will be hard and perfectly viable. However, I like higher conditioning values, and I like my Sat: Unsat ratio to be at least 40:60. so let’s see what happens if I add a luxury oil into the mix.
Recipe #4 – Addition of Meadowfoam Oil
Meadowfoam oil is a luxury oil that is fairly expensive but it does add quite a bit to the conditioning value of the soap. In the recipe below, in order to keep the total at 100%, I deducted a couple of percent from the olive oil and cocoa butter.
Notice that now the conditioning value is 60! Fantastic! The creamy value took a little bit of a deduction (37 to 34 now) and the INS value has dropped, but is still over 140. The hardness is now 37 versus 40. The sat:unsat value is now 38:62. Overall this is a great soap recipe (IF you have meadowfoam oil).
Let’s take a look at a more commonly available oil – Avocado.
Recipe #5 – Avocado Oil instead of Meadowfoam Oil
Now we will just swap out the meadowfoam oil with some avocado oil. Seems like a fair trade, right? I mean, avocado oil is known to be very nourishing to the skin and is great for aging skin. But what happens to our recipe then?
All we have done is replace the meadowfoam oil from the previous recipe with avocado oil. Look at how it has changed our values. The hardness has increased to 40. The conditioning value has dropped from 60 to 56 (sad). The INS is still great, but the sat:unsat value is now in a range that could potentially cause some acceleration (42:58 is not as desirable as 40:60 or above).
It appears that even though avocado oil is a wonderful oil, it is not coming across this way in this recipe. Maybe it is not the right oil for this soap. Maybe it would be better in a soap with a different combination of oils and butters.
Let’s try another more conditioning oil that is a less expensive and more readily available oil than meadowfoam is.
Recipe #6 – Safflower Oil (high oleic)
Safflower oil (high oleic) is readily available. Grocery stores carry it. High oleic just means that it is high in monounsaturated fat. If you look at the label of the oil, you should see this reflected in the nutritional chart. It will also likely say “High Oleic” on the label because it is a selling point.
Let’s see what the recipe looks like when we replace the avocado oil with safflower (high oleic) oil.
The addition of safflower oil has lowered the hardness value down to 38, but it has restored much of the conditioning (we are back at 59 now). 38 (hardness) is still a pretty good number, so I am happy with this.
The bubbly and creamy values are desirable and the INS value is high (148). The sat:unsat values are good (the unsat value is over 60). So it looks like we have a great recipe here.
While the one with meadowfoam would be a more luxurious soap, this one is more economical and close to the same values. You could use either one really, if you have the meadowfoam oil and don’t mind the expense.
You may notice if you look back to the beginning of this article that the simple soap with just olive, coconut and palm oils was actually a pretty desirable recipe as well. It is just that without the addition of castor oil, it was pretty low on bubbly and creamy values. Once we added castor, the soap became pretty soft though, so we had to add some cocoa butter to harden it up a little. But then we lost some conditioning, so we added a conditioning oil and now we have a recipe that is the best average of all the soapcalc values.
Now strange things do happen, especially when you use fragrances and colorants in the soap, but the soapcalc prediction tells us that this will be a very good bar of soap.
The rest of the recipe
Ok we have narrowed down our oils now, so what about the numbers at the top of soap calc?
Well, my silicone soap mold holds about 22 ounces of soap (full to the brim), so from experience I know that the weight of my oils should be between 14 and 14.5 in order to yield the right size. If you are not sure what number to put here, just wing it for now. When you look at the printable recipe, it will tell you the overall volume of the soap batter and you can always come back here and adjust it up or down depending on the volume you need.
Soapcalc always puts 38% for the “Water as % of oils”, but this is a lot of water. I always change this to 34. You can go lower if you like, but the more you discount the water, the more likely you may have acceleration of your soap batter. 34 to 36 seems to work well for me. If you will be using a fragrance that you know will accelerate, you may wish to use the full 38%. You will have to leave the soap in the mold longer before you unmold it if you do. The more water that is in the lye solution, the longer the soap will take to unmold and the longer it will take to cure the soap. The lye and liquid must be at least a 1:1 ratio or it will fail to form a solution. If you go under 33% here, the soap will thicken very quickly and could accelerate if you are using fragrances. In my experience, depending on the fragrances being used, 34 to 36 has worked well for me.
Now for the superfat. Superfat is an indication of how much of the oil you put into the soap will remain oil (and not turn into soap). Having a little bit of freely available oil can replenish the oils you wash away from your skin while bathing. So having a little bit of superfat equals moisture for your skin.
Soapcalc always puts 5% as the default superfat level. I like 5% superfat. It is a good amount so that there are not too many unsaponified oils that could go rancid. I usually leave this at 5%, but if you want to use more coconut oil to make the soap harder, you can increase the superfat level. This will offset the drying effect of the soap by leaving behind more oils to replenish the skin. I would not increase it more than a couple of percentage points, but soap making rules are made to be broken, so feel free to experiment. Just know that if you make it too high, you will likely end up with very soft soap that is prone to rancidity.
As for the fragrance amount, I just leave the defaults. I usually go look up the fragrance in a fragrance calculator. Since I buy most of my fragrances from Brambleberry, they have a very handy calculator where you can pick your specific fragrance, and it will calculate how much to use based on the size of the soap batch. Other sites such as Natures Garden will tell you the ideal percentage to use for their fragrances.
And finally, the printable recipe
Once you click on the soapcalc page where it says “print recipe”, it will bring up a separate tab that shows you the recipe in its entirety. This recipe will tell you how much water, lye and oils you should use, as well as the amounts of oils.
There are other metrics about the soap such as the total weight of the oils, total weight of the batch, lye concentrations, superfat amount and so forth. It also shows you ounces, grams and pounds so depending on your measurement system, you can use that column.
You can see the total volume of this recipe is 21.89 ounces. So it will fit in my mold (which holds 22 ounces). If it were the wrong size, I would go back to the previous screen in soapcalc and adjust the weight of oils, then recalculate the recipe and check it again until I got the right amount worked out.
You can type in some notes at the bottom (notice, I typed in “Sodium Lactate – 1 tsp”). Using sodium lactate can help the soap last longer in the shower, be harder, and be ready to unmold quicker.
Below the recipe it also shows you your soap calc values (hardness, conditioning, creamy bubbly, etc). You can print this recipe and use it to make your soap.
Also notice at the top right, there is a button called “INCI names”. This is a new feature. It will tell you the correct names to put on your soap labels based on the oils and amounts you have chosen. Handy!
You can print this page, or, depending on your computer setup, you might be able to save it as a PDF (my computer offers me this option from the print dialog window).
Here is the recipe if you wish to try it out:
As a side note, you can see the properties of each individual oil by clicking on the oil in the list and looking at the “Soap Quality “Fatty Acids column. It is the white column in the left bottom section of the below picture. I am guessing based on the values it is showing that I have clicked on Olive Oil since the hardness is so low (7) and the conditioning is so high (92).
I have purposefully left out a big chunk of soap making education with this article. There is a whole other section of soapcalc which tells you the fatty acid profiles such as Lauric, Mystiric, Palmitic, and etc. Knowing these values of your oils can make it easier to understand how specific oils will behave in your soap. However, I do not use this very much. I let the calculator do the work for me. In order to calculate the hardness, cleansing, conditioning and etc… soapcalc has already tallied the properties for me.
It is a lazy approach, but growing up I was told that I would need to memorize my multiplication tables because you can’t carry a calculator everywhere you go. Well, many years later, I have an iPhone, so take that math teacher! 🙂 True, if we have a power outage, I probably can’t make soap because I haven’t memorized my fatty acid profiles. But that is a risk I am willing to take. If the power goes out for that long, then I have bigger problems than soap.
I hope this comparison helped you understand how to use a soap calculator better — at least soapcalc.com. And I hope you feel inspired to go create your own soap recipes. Once you get the hang of it, you will enjoy the freedom it gives you to be able to pick your own oils and butters to make your own unique favorite soap.