One of the questions that I get asked most often is, “How do I make my soap harder?”
Here are a few ideas to get you started. It really takes experimenting to find what works best for your recipe.
Evaluate Your Oils
Take a look at your recipe. What is your percentage of hard oils and soft oils? For the most part, hard oils and butters make a hard bar of soap and liquid oils make a soft bar of soap. There are two exceptions.
Olive oil – Olive oil is initially soft upon unmolding but cures out rock hard. Have you heard of or used castile soap before?
Castor oil – Castor oil is another oil that starts off soft and sticky in soap but cures to be hard.
If your recipe is full of any other liquid oils such as rice bran, soybean, avocado, sunflower…etc., these will make a soft bar of soap.
My typical mix of oils is something like this:
Coconut oil – 34% (Hard)
Olive oil – 34% (Hard)
Avocado oil – 8% (Soft)
Rice bran oil – 14% (Soft)
Shea butter – 10% (Hard)
This makes an excellent bar of soap. For more info on oils in soapmaking, download my free Soapmaking Oil Chart!
Evaluate Your Superfat
What percentage of excess oil remains unsaponified in your soap? A higher amount produces a softer soap. If you are superfatting your soap at 8%, try 5% and see if that helps.
Olive Oil
Which olive oil do you use? From personal experience, I have found that Refined A or Regular olive oil is the best olive oil to use when making soap. I usually get Refined A from soaperschoice.com.
I know lots of soapmakers use pomace olive oil (mainly for the price) but I stay away from it. Pomace has many unsaponifiables in it which make for a soft soap and is also usually tinted a funky green color that messes with my color additives. I do not like pomace olive oil…at all.
Don’t take my word for it, though. Do a side by side test with pomace and refined A and see which you prefer. (I bet refined A wins.) The refined A will come out lighter in color and harder (especially after the cure).
Stearic Acid or Beeswax
Both of these ingredients will harden your soap. Both of these ingredients can also be tricky to work with. You have to soap at hotter temperatures to make sure they don’t solidify in your mixing pot.
I personally don’t use them because I soap at cool temps. If you do want to experiment with them add 1/4-1 teaspoon (per pound of oils) of either beeswax or stearic acid to hard oils/butters and melt.
Sodium Lactate
Sodium lactate is used by soapmakers to make a harder bar of soap. I used to use it a lot…until I learned to better formulate recipes without it.
You can get info on how to use it at Bramble Berry’s website here. Start with 1/2 teaspoon per pound of oils (added to cool lye solution) and go up from there.
If you use too much, it can make your soap crumbly where it breaks easily.
Add a Pinch of Salt to Lye Solution
Salt adds initial hardness to cold process soap. Here is an article from David at About.com about adding salt to soap. http://candleandsoap.about.com/od/tipstricks/qt/qtsalt.htm
I actually add it after I mix the lye so the hot lye solution easily melts the salt.
It is important to note that salt does kill lather in higher quantities. Have you ever made a salt bar? So if you want to experiment with adding salt in higher quantities, just know that you can lose some lather.
1/4-1/2 teaspoon per pound of oils seems to be the ideal range.
What do you do to make a harder bar of soap?
I’d love to know what you do! If you are a soapmaker and can offer advice for hardening soap, please do so in the comments!
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Happy Hard Soapmaking!
-Amanda Gail
Recently gave try using stearic acid it did not give time to pour soap in mould.
I don’t know how it happened or it’s real yesterday I used Rose clay in soap and I could easily unmould and hard bar came out without crumble
Lauri, I just saw about soap scum in soap making.
Does it actually clog the drains ? and if so will vinegar cut the scum or do you have recommendation ?
I just started using homemade soap and it helps the dry skin but now worry about clogging. as I do see scum if I take a bath
Thank You,
Lauri, I just saw about soap scum in soap making.
Does it actually clog the drains ? and if so will vinegar cut the scum or do you have recommendation ?
I just started using homemade soap and it helps the dry skin but now worry about clogging. as I do see scum if I take a bath
Thank You,
Jane
Oi Amanda! Minhas barras parecem duras mas quando começo a usa-las vão ficando linbosas e amole endo.. voce tem ideia porque? Uso Palm oil / coconut oil/ canola / castor / e 2 colheres de shea butter na massa ..
Vou assinar seu canal ?!
Hi!! I have a question.
What plays a role for fast trace?
The temperature of the materials, the percentage of water and lye, or the superfat?
Perdoem…mas eu adoro o sabão de azeite. Sabem como faço? Simplesmente…com água do mar. Fica divino…
Oi Margarida. procure receitas de sabão de castrla, ou castille soap. o melhor é adicionar sal à tua lixívia, pois nao tens controle da qualidade da água do mar, se tem metais, quais minerais etc. mas podes testar com alguma agua do mar e ir testando. passa na calculadora, pois castille é feito com 100% de azeite(olive oil). espero ter ajudado. bj
You offer up so much valuable information to all of us. I just want to say thank you .
Hi, thank you for the great info! I started soap making at home as a hobby since last January and I have made so far three batches with olive oil, or lard alternatively, (80%), coconut oil (15%) and beeswax (5%) and small quantities of honey and fresh aloe vera extract. The soap produced is hard, long lasting and cleans very well. Now I will start experimenting with natural colors and aromas, starting with dried and grinded orange and bergamot zest. I have a question and I would appreciate it a lot if someone has some experience concerning this specific case. Recently I have collected lots of slightly used soap bars and leftovers (about 5 Kg of industrial production, not homemade ones!) from friends with the aim to rebatch them in new soap bars. Unfortunately they end up very soft. What could I possibly add to increase the hardness of the new soap bars?
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add rice flour and besan flour to your soap both are good for skin naturally besan flour exfoliate skin rice flour gives brightness and ur soap also became harder
Amanda thanks for you information, i need an advice : make a vegetable soap based on olive oil, sunflower, almond and a minimum of soybean butter, however the soap takes in cool.process one week I try to cut it but it is very hard, the consequence when trying to break it is that it fracture .. . What I can do?
Mamy many thank for you advice.
Can olive oil increase harder on soap?
Was curious is this recipe will make a hard with bar of soap with a good lather:
40% coconut oil
30% olive oil
5% castor oil
10%avocado oil
15% shea butter
Also I wondering if adding lacticd acid is necessary? As a natural colorant I am adding clay as well, does that make a harder bar? Also is that to much coconut oil? Will that be drying to the skin or does the other ingredients counter act it
Whoops I meant sodium lactate***
Michelle, while that would make a hard bar, 40% Coconut Oil is going to be extremely drying to the skin. You could do a small batch & see how it feels to you though.
I have some 70 yr old super hardsoap that my Greatgrandma made. Its quite brown in color and lasts and feels great. She was known for her “HARD” soap which lasted longer on the old washboards. She never wrote her recipe down before she died. Always had a fire in the back yard making a batch. Traded bars in exchange for supplies to make it. Kept her alive during the depression and she never had to buy bread a day in her life due to trading soap for flour. I’ve heard that she used what ever ppl had as extra, including milk beginning to go bad. Used ashes for lye?
PLEASE PLEASE someone help post or send me a few recipes to try. I love to try and duplicate her & learn her trade for honor’s sake! I just need a simple recipe that I can try and duplicate. For automotive grease, it works 10x better then any modern bar soap ot soft soap I’ve used. Super soft, supple skin when using it. It also makes a loud tinging sound when I drop it back on a metal plate soap dish and a bar last forever. I don’t care what it smells like.
Please help and thanks in advance.
Hi Bruce. My grandmother made soap during the depression and all of her life. While I don’t have her actual recipes, I do know that she used saved fats, such as beef (tallow) and pork (lard) in them. Nowadays you can buy those from companies like https://www.soaperschoice.com/animal-fats . I don’t think she used ashes for lye, which creates potassium hydroxide and is used for liquid soap. Sodium hydroxide is used for bar soap, and has been commercially available for many years. Here’s a formula that David Fisher posted several years ago on About.com for hard white soap: http://candleandsoap.about.com/od/soaprecipes/a/hardwhitesoap.htm These make a very hard bar. I’m not sure what she used that caused it to be brown, probably an additive such as milk (the sugar in milk can caramelize from the heat during saponification and turn soap a brownish color or she may have hot processed), sugar, molasses, etc. If it’s good for mechanic’s hands and had an exfoliating texture to it, she may have added pumice. Be sure to check out Amanda’s basic soapmaking directions and safety information before attempting any homemade soap recipe, and become familiar with a lye calculator, such as the one at http://soapcalc.net/calc/SoapCalcWP.asp before attempting to make any changes to the recipes. Good luck!
To make lye from ashes it takes 3 buckets…..bucket 1 is used to mix your water and ashes……bucket 2 has holes in the bottom to allow fluid to pass through and is filled with straw…….bucket 3 is placed under bucket 2 to catch the lye solution that passes through bucket 2…..You mix your crushed ashes with water in bucket 1 mixing well…….Let set for a day or two…….Pour the contents of bucket 1 into bucket 2…..Allow the contents of bucket 2 to completely drain into bucket 3…….Take contents of bucket 3 and pour back into bucket 1 where you add more crushed ash to the solution…..You continue to do this until the desired PH level equal to lye is reached….then you make your soap out of it.
We can be almost 100% sure that your Grandma used LARD in her soaps in high quantity, if we think of what might have been available to her in those days for sure she would have used Lard or any animal fat that was rendered and saved not sure if vegetable oil existed at that time. Lard is very conditioning to the skin, however today people are so hung up on animal fat and wanting vegetarian and vegan. I make a laundry soap that I make with approx. 75% lard and 25% coconut, plus 2% tea tree EO and Orange EO, both great for getting clothes clean when used together.
I am new to soapmaking. Just added coconut oil to my soap so it can lather up, but seems like it is soft instead hard. I have to find kut what oils to use to get lather and stay longer.
Does Shea Butter makes soap last longer and harder?
Coconut by self doesn’t necessarily make soap lather. Sometimes, it’s a combination of other oils like caster and palm. You might be using too much coconut. You could be using too many/much soft oils that decrease lather. Higher percentage of hard oils can also decrease lather. Check your recipe. Run it through a lye calculator like soap calc. That’s not the definitive anwser, but a place to start. Amanda has great recipes and articles. Start there.
it is a valuable informations . many thanks Amanda
i used to use 10 % stearic acid that give an accepted result
Thanks for sharing
I typically do a water discount as well, and use up to 40% coconut oil in many of my bars. Freezing makes it hard enough to cut initially, and cures a little faster, too.
I use 1 tsp of salt per pound in my hot lye water. To help offset the decrease in bubbles, I add 1 tsp of sugar mixed with water to melt and add to my oils, then pour my lye water in and mix!
Hi Amanda,
just wondering about your recipe. It is a high percentage of coconut oil. I always thought that at that level the bar would be too cleansing. How do you find 34% of coconut oil on your skin? and what superfat would you be using with that recipe. Just curious 🙂
Sarah
For me, i have few more way to harden the soap.
1. Instead of using sea salt which can reduce your lather, try to disolve 2-3% of sodium citrate and add to your soap. Not only it hardens the soap but also contributes to the lather because a builder it is.
2. Discount your water, My preference ration of water : lye is 3 : 2 aka 33% lye solution.
3. I don’t like bee wax at all, make the soap slippery and reduce the lather. I use spy wax instead which is mainly strearix acid, an saponifiable fatty acid. Soy wax makes the soap harder and adds a bit lather/stability too.
Hi Huy Nguyen, Is that sodium citrate (citric acid) 2-3% of oils? Would love you have more information on this. Thanks 🙂
thanks so much 4 yr advice
Hi, nice article, what I’d like to do, is to use 1/2 – 1 tsp of salt in lye water per kilo of oils, and just to be sure that it wont cut my lather, I also add sugar! I am very content with the results, and another thing is that I use about 60% or so, hard oils.
May sound useless but I feel that Whenever we talk about Hard and Soft soap bars, there always should be a link where the reader can see a comparison of good and bad between Hard and Soft bars. We all know that both have their own goodness.
I like all the combination of oils..Everything is absolutely healthy and natural. I like the recipe. Thanks you
Best regards
While it is less frugal than making your own lye soap, it is much safer, less expensive than commercial soaps, and still handcrafted. You still have to supervise children with heating the soap on the stove or in a microwave so that they are not burned, but the ingredients themselves are not caustic.
I love your blog! I also love stearic acid and beeswax. I use low percentages of both in all my soaps. I don’t add them ppo though, I include them in my lye calculator and melt with the other oils. In low percentages there shouldn’t be any issues with untimely hardening or accelerated trace. Stearic is more or less my secret weapon. It adds an unforgettable, lovely creaminess to soap lather as well as hardness to the bars.
I love your blog! I also love stearic acid and beeswax. I use low percentages of both in all my soaps. I don’t add them ppo though, I include them in my lye calculator and melt with the other oils. In low percentages there shouldn’t be any issues with untimely hardening or accelerated trace. Stearic is more or less my secret weapon. It adds an unforgettable, lovely creaminess to soap lather as well as hardness to the bars.
Hi there,
Love your website. Would you be able to help me formulate a shave soap? I dont want to use palm, tallow or lard. I do want to use some clay, and I plan on pouring these into individual glass containers to cure. Please help!!!!
Thanks for all the valuable information. I live in AZ and I cannot find anyone here that is willing to share any info on the subject of making soap making. Thank you very much for all your helpful posts.
Do you have any go-to pet bath bar recipes?
I don’t, Pam! I’ll look around and let you know if I find anything. The main thing to research is the essential oils that you use. Make sure they are safe for your pets.
Olive oil not only makes a hard bar of soap, it makes a gentle bar, suitable for even the most sensitive of skin. For centuries olive oil has been used to soothe and soften the skin (remember Cleopatra?). It is rich in vitamin E, beta-carotene, and antioxidants to stimulate new cell generation. At Herbonita Soap Company (www.herbonita.com) all of our soap except the salt bars and a couple specialty bars is made with a base of 60% olive oil. Yes, they take longer to cure….we allow a minimum of four to six weeks depending on the weather….but our bars are very hard, produce lots of lather, and are very gentle to your skin. All of our products are made of the best all natural ingredients in small batches to assure freshness, and are scented (or not) only with essential oils.
A word about coconut oil….it is a very good cleaner, it makes lots of bubbles….but in too high a percentage it makes a bar of soap that dries your skin. Most experts suggest keeping the percentage of coconut oil at fifteen percent or lower.
To combat the dryness of coconut oil I use a higher superfat, 7% minimum is what I use, my rule is for every 5% of coconut I want to be sure I have 1% superfat, so for 34% or 35% coconut I like 7%, at 5% I find the soap to drying.
I use the INS Value and the Iodine value on SoapCalc dot net to determine the hardness of a bar. An INS value of 160 is so-called “perfect” soap; Iodine value at 55 or lower determines the hardness of a bar. I use the Sat/Unsat feature to balance the formula close to 50/50 or thereabouts. Works for me. ; D
This is a timely post! I often use MP embeds as embellishments for my CP soap, but I’d like to start experimenting with making harder CP that will come out of a mold. Thanks for reminding me that I need to get busy 🙂
If “Olive oil is initially soft upon unmolding”, and if my main purpose is to create a CP embed recipe that allows me to easily unmold CP from a silicone mold, should I go with less Olive Oil?
Since I don’t have any Rice Bran Oil or Avocado Oil on hand at the moment, I was playing around with the numbers for this possible recipe:
Coconut Oil, 76 deg 34%
Olive Oil 34%
Lard 22%
Shea Butter 10%
But then I went back and read your statement that reminds us that olive oil is initially soft. So do you think I should cut back on the Olive Oil in my experimental recipe, and up the Shea and/or Coconut? And, if so, do you have a suggestion for how much I should cut back on the Olive Oil?
Thanks for your help and your expertise!
Linda
Linda, that recipe actually looks great! Beyond olive you don’t have any other soft oils, so that is going to be a nice hard bar of soap.
You don’t think I’d have trouble unmolding it?
I think you’ll be find with all of the hard oils/butters.
it is a valuable informations . many thanks Amanda
i used to use 10 % stearic acid that give an accepted result
Great article! I mostly make HP soaps. I’ve tried Refined A Olive OIl but have gone back to Costco’s Kirkland Pure Olive OIl – it’s the lightest in color and not a blend. My “go-to” recipe also uses Castor Oil, Cocoa Butter, Shea Butter and Sodium Lactate @ 1tsp/ppo. SF is around 7% and water is 36-38%. The bars cure a minimum of 1 week and are pretty hard at that point. After 2-3 weeks they are usually very hard and at 4 weeks are pretty much rock hard. I haven’t tried stearic acid/palm stearic yet and may at some point but I try to keep my ingredients to a minimum.
Thank you for the great information. Always helpful.
Less is more. I have used pomace, but just for the family and have learned to strain strain strain through cheesecloth . then, haha…i put that wrung out cheesecloth in a clear jar
wrap tightly w saran, poke a few holes and watch the rotten fruit flies that summer composting always brings go in and not come out. nasty little buggers.
I add a tiny bit of bentonite/sodium lactate to those bars, whatever green or blue green colorant I have and a gold mica pencil line…and some of your ravishing EO combos and voila ! a new just family shower bar every time.
I have to admit, I superfat really low 2% because I was sick of so much soap scum build up in the drains. It’s true, the less superfat, the harder the bar. Still feels nice… And, I always use castor for bubbles in the bar…
hmmm, nothing else to ponder here, but I’m definitely filing this post as a valuable one for future referance !!!
laurie
Lauri, I just saw about soap scum in soap making.
Does it actually clog the drains ? and if so will vinegar cut the scum or do you have recommendation ?
I just started using homemade soap and it helps the dry skin but now worry about clogging. as I do see scum if I take a bath
Thank You,
Jane
Thanks for the great info, Amanda! I don’t use stearic acid because it’s often made with palm oil. I’ve used 1 tsp of sodium lactate ppo without any problems. It mostly just makes it easier to unmold; haven’t noticed any extra hardness over time. I also make some soap with tallow, which makes a firmer bar.
Hi there, i usually use stearic to harden my bars..beewax also works well. I may try salt to see how it turns..thanks for the info amanda..love your tutoriales
I enjoy getting your posts and this one especially-it will help alot. I have made several recipes out of the recipe book and love them. Keep up the great information.
Hi Amanda!!! Nice info !!! I use stearic acid in same recipes. Beewax is “the missing of bubbles” ( I tried it ONCE)
Love these ideas and the salt definitely works! Xoxox
Thanks for the tips! I have used sodium lactate and didn’t know it can cause a crumbly bar if too much is used ~ this is very good to know (more is not always better) Thanks!
Great info! I just love your blog! My base recipe seems to be just fine without any of these. But, I have been thinks bag of adding something for when I do HP. I add lots of extra water, so they take forever to harden up.
To make a harder bar of soap, I balance hard and soft oils. Some of the lye calculators let you know how hard your bar will be. I have found that to be useful.
I’m really new to soap making and am going to try the little bit of salt tip. My bars seem to be coming out just fine after they cure long enough. Still playing with my recipe though. I had one bar stay rather softer, but I used pomace in it.
Great info!! I made a soap about two months ago and it is still so soft I can press dents into it. Oh well, learn and grow!
I really love your website, you have helped me so much to learn how to be a better soaper.