Tips on how to cure handmade soap and ideas for storing it. Curing is the process of allowing saponification to complete and for the soap to fully dry. It takes about a month to complete #lovelygreens #soapmaking #curingsoap #soaprecipe #soaptechnique #naturalsoapmaking #howtomakesoap
|

How to cure handmade soap + ideas for storing it

Tips on how to cure handmade soap and ideas for storing it. Curing is the process of allowing saponification to complete and for the soap to fully dry and takes about a month.

Handmade soap needs to cure before you can use or sell it. You may have heard about it before, or done it without understanding why or for how long you should cure different types of soap. I hope to answer those questions in this piece and to provide guidance on exactly how to cure soap, and ways to speed up the process.

Contrary to what other sources may say, you need to cure soap whether you’re using the cold-process or hot-process method. That’s because it’s just as much about letting the bars dry, and form a crystalline structure, as it is about saponification. This piece goes through what’s involved in the curing process, why it’s needed, tips on how to cure your soap faster, and finally how to store your soap when it’s fully cured. If you’re new to soap making, here’s an introduction to making cold-process soap.

Tips on how to cure handmade soap and ideas for storing it. Curing is the process of allowing saponification to complete and for the soap to fully dry. It takes about a month to complete #lovelygreens #soapmaking #curingsoap #soaprecipe #soaptechnique #naturalsoapmaking #howtomakesoap

Why the need to cure handmade soap?

Even though it looks good to go there are three reasons why you need to cure freshly made soap. Firstly, it’s to allow saponification to complete. Saponification is the process where the oils in your recipe are broken apart by, and bond with, the lye. This process is mainly complete in the first 48 hours after you make cold-process soap but the remaining 1-5% of lye needs up to a month. In hot process soap, saponification is finished by the time you finish the cooking phase but there’s still a lot of water content in the bars. 

Curing handmade soap is a great deal to do with evaporating the water content out
Curing handmade soap is a great deal to do with evaporating the water content out

The cure time dries your soap out

The second reason we cure soap is, to let the water content evaporate out and the bars, and for them to dry. When making soap you dissolve the powdered sodium hydroxide (lye) into distilled water, and sometimes a different liquid that will have a water component. That water is still in your bars when you take them out of the mold. If you don’t allow them to cure and dry then your bars will not last once you start using them. They can also have impaired lather.

The cure time will reduce the amount of water in your soap over a period of 4-6 weeks. By the end of that time, your bars can lose over half of the water they originally contained. One way to know that your soap has hit the minimum amount of cure time is to weigh the bars each week and to keep a record. Once they stop losing weight, they’re ready to be used.

Shop Up to 30% off ALL HERBAL COURSES!

Both cold-process and hot-process soap need to be cured to allow this excess water to evaporate out. Because hot-process soap uses even more water than cold-process, it’s actually better to cure it longer. Though some water will evaporate out during the cook, it will usually contain more water on the pour than cold-process recipes.

Curing handmade soap is a great deal to do with evaporating the water content out
Soap cured for at least four weeks is milder and will have better lather

Crystalline Structure Development in Soap

Lastly, the longer soap cures, the milder the soap and the better the lather will become. That’s because, over time, at least four weeks, the liquid film surrounding each soap molecule has a chance to develop fully. It’s a complicated and chemistry-related discussion and the process is fully explained over here. All you need to know is that soap’s lather, cleansing ability, and mildness get better with age. There is no way to speed up this process as an artisan soapmaker.

Freshly cut handmade soap is just slightly moist but there's a lot more water inside the bars
Freshly cut handmade soap is just slightly moist but there’s a lot more water inside the bars

Unmoulding & cutting handmade soap

I go through explaining this process a lot in my cold-process soap making lessons. That’s one reason that I’m writing this piece — it’s so that I can send the link to my students after a lesson. I hope it can help you too!

If you’ve made cold-process soap, I think it’s best to leave it in the mold for 48 hours. This means that by the time you take it out, the vast majority of the lye has bonded with the oils. Up to 99% of saponification is complete at this time. After two days it’s safer to handle and will be harder than it was the day before.

I’d advise wearing gloves for handling your bars at the point of unmoulding. It’s unlikely that you’ll feel anything uncomfortable but there could still be lye in the bars. Touching fresh soap that’s lye-heavy can cause skin dryness and irritation, especially if you have sensitive skin.

If you’ve used a loaf mold, slice your bars up. This will increase the surface area for drying and cutting fully cured loaves can be more difficult. The size you cut them is up to your personal preference. The soap I sell is about 1″ thick.

You can stack soap while curing. Just ensure that there's plenty of airflow
You can stack soap while curing but ensure that there’s plenty of airflow

How to cure handmade soap

Once your bars are un-molded and sliced it’s time to cure them. There are many places that you can cure your soap but the premise is all the same. It needs an airy place out of direct sunlight. You can use a bookshelf, metal racks, cardboard boxes, stacked milk crates, or even make towers of soap. Stacking soap during curing is perfectly fine and if you live in a warm and arid place, you could even cure your soap outside. That’s how it’s been traditionally cured in the Mediterranean and middle east. I’ll pop a video below for you to see how they do it.

Even though your bars are firm at this time, they still contain moisture that can react with surfaces. That’s why we line them with greaseproof or baking paper to protect both your soap and the units you’re using to cure it on/in. Then space your bars out so that there is plenty of airflow around them. Again, feel free to stack them, as long as there’s plenty of air that can circulate.

Even if you’ve only made one batch of soap, it pays to label it. Mark the date you set them on the shelf and also which soap it is. It could be a batch number or simply the recipe name. If you have different batches, feel free to place them side by side but keep them from touching. If you’ve used different scents, they can affect each other during that long cure time. Sometimes also if they’re not touching, so keep that in mind. Also, the cure time begins not from the day you made the soap, but from the time you set it on the shelf.

Curing soap on a metal rack lined with baking paper
Curing soap on a metal rack lined with baking paper. The pink soap is my cochineal soap recipe

Soap curing time

The time you leave your soap to cure is dependent on the oils and water content of your recipe. Four weeks is a good enough time for the majority of cold-process soap recipes. Err on the longer side if your bars contain a lot of olive oil (60%+ of a recipe). Castile soap (100% olive oil soap) is harder, milder, and much better quality if you give it at least six weeks to cure — if not six months to a year. That’s because of how the crystalline structure forms in soap recipes with high amounts of particular fatty acids.

In hot process soap making, some of the water in the recipe will evaporate off in the cooking process but not enough to reduce the curing time. In fact, it’s better to cure hot process soap for longer than cold-process since it can contain more water.

Curing three batches of Turmeric Soap. The speckles come from the spice.
Curing three batches of Turmeric Soap. The speckles come from the spice.

What happens if I don’t let my soap cure?

There are a few things that can go wrong if you don’t allow your soap to cure. First of all, it could still contain lye. Even though (cold-process) saponification is mainly complete in the first 48 hours, there’s still a chance that your bars will contain lye for up to a month. Lye heavy soap can cause skin irritation and I imagine that there’s a potential for damage if it gets in your eyes.

Curing lets the water content of the soap evaporate out leaving you with harder bars. Soft uncured soap can disintegrate quickly if you get it wet and also have impaired lather. The impaired lather isn’t necessarily from the water content itself but by the way that it affects how the crystalline structure of soap forms during the cure time.

Young soap bars that are a week or two old can technically be used — both cold-process and hot-process. However, they won’t lather, clean, be as gentle, or last as well as soap that is fully cured or older. The older your soap is, the better it will be.

If you decide to package up uncured soap it could spell disaster too. The moisture can destroy your labels, create condensation under plastic, and otherwise ruin your product.

Ways to cure handmade soap faster

There are a few ways that you can shorten aspects of the cure time of soap. As mentioned previously, you can’t really speed up the process of soap molecule formulation. Since the process happens as the bars dry out, speeding up the evaporation of water in soap may help.

The first is to use the water discounting method, which means to use lye solutions with less water. In a standard recipe, you use a 25% lye concentration. For example, if your recipe calls for 100g of lye then you’d make your lye solution with 300g of water (100g is 25% of the total weight of 400g). Making your lye solution stronger, means less water, and a shorter curing time. Still, it is best to cure your bars for at least four weeks.

For most of my recipes, I find that a 35.7% water discount works really well, even for beginners. To get that amount, simply multiply the amount of lye in any soap recipe by 1.8.

The absolute minimum amount of water you can use is equal to the amount of lye in your recipe (a 50% concentration) but this is only advised for advanced soap makers. Creating stronger lye concentrations speeds up how quickly your soap comes to trace and hardens. If you don’t work quickly, it can sometimes become unworkable. It can also affect how evenly your soap gels and cause other issues including cracking.

Ways to Speed Up Water Shedding in Soap

Another way to cure handmade soap faster is to use a dehumidifier. I keep one going in my workroom when soaps are curing. The time it takes the soap to shed excess water will vary but if you weigh a bar regularly and notice that it’s not losing weight then it’s probably ready. You can also cure your soaps outdoors if it’s warm and very dry. Make sure to keep them out of the sun and that they have really good airflow.

An electric fan blowing on soap could also reduce your cure time. Again make sure to weigh your soap at the beginning of the cure time and keep an eye on the weight regularly. If you’re going to use this method it really helps to know the weight of a fully cured bar of soap. If you’re using the same batch and size as a previous batch weight one of those bars.

The best place to store handmade soap is in the open air. A box can double as a storage container and as a market display
The best place to store handmade soap is in the open air. A box can double as a storage container and as a market display

Storing handmade soap

Once your soap has fully cured, you’re able to use, gift, or even sell your bars (providing you have your business, insurance, and beauty documentation set up of course). You can also wrap them in paper packaging.

Wrapping them in plastic is a bad idea though for two reasons. First of all, single-use plastic is frowned on these days. There will be customers who won’t want to buy it if there’s anything plastic about it. Secondly, if there’s even the tiniest amount of moisture still in the bars it won’t be able to escape.

That means that excess moisture could cause your bars to get Dreaded Orange Spot, literally orange spots on the bars. The spots can get icky and have an unpleasant odor and are an indication that the soap has gone rancid.

Store Soap in the Open

The best place to store handmade soap is in the open air. One idea is to store them in a wooden box that also serves as a farmer’s market display. Simply leaving them on the curing rack until they’re needed is also common.

Please be aware that if you store handmade soap in sealed containers, such as tupperware, then it can greatly reduce the shelf-life of your soap. That’s because the natural glycerin in soap attracts moisture to it. You could one day open that container of soap to find beads of moisture over the bars and signs that the soap has gone rancid.

Shelf-life of handmade soap

This can be easily calculated by looking at all the labels of all the ingredients you used to make soap. The closest best-by date is the best-by date of your new batch of soap. Making soap doesn’t prolong the life of oil about to go off. Using old oil can also cause the Dreaded Orange Spot mentioned before.

Some fresh oils have a shelf-life of two to three years though; coconut oil for example. Make soap with oils that have the longest natural shelf-life and that are well within that best-by date will pay off. It will ensure that your soap will not only last a long time but that you can cure soap for longer, creating better bars, without the fear of them going rancid.

For even more soap making ideas, recipes, and tips head over here.

53 Comments

  1. I am new to your site and enjoying reading everything I can about soap
    making!
    I have a small greenhouse (4ft by 3ft by 18 inches) in my basement I use for starting my seeds in the spring. Can I put my soap to dry in that and leave the doors open in the front? I was concerned about the temp only being about 68 degrees.
    When I start my plants I use a heat mat for warmth.
    And should I use a small fan for circulation?
    Thanks for any info!

    1. Hi Barbara, room temperature is perfectly fine for allowing soap to cure. It does not need to be warm during the curing weeks and you will not need a fan. They just need to be in a dry place out of direct sunlight :)

  2. where do I store soap used in the shower? I read that it will melt if left on the soap dish while wet. BTW, loving your website!!

  3. Hi Tanya!

    I’m just about to begin making my first cold-process soap and are scouring the Internet for everything I can find on the subject. So excited! Found your site and absolutely love it. Even by just reading the post about curing the soap I found answers to several questions I had and I look forward to check out your other posts, both on soaps and gardening.

    Just want to say Thank You for sharing! This site is a gem. ❤
    Of course subscribed to the newsletter.

    Have a nice day!
    /Lisa from Sweden.

  4. First time in soap making
    *Please can liquid soap base be used in bar soap making
    *How many minutes does it take to melt
    *Do I have to combine with lye in bar soap making?

    1. After you make soap (from a good recipe) there is zero sodium hydroxide left in the soap. It reacts chemically with oils/fats and the result is its own compound — soap! And to answer your question — no, there is no way for us to test sodium hydroxide levels in soap. The only way that there could be any in it to begin with is if the person accidentally added too much, or they didn’t use a correctly formulated recipe.

  5. I had a question Im new to soap making and made a melt and pour soap batch and when it was done hardening it was pretty greasy I used 4tsp of lavender oil to 450g of soap was that too much or will curing it make the oilyness go away?

    1. Hi Priscilla — with m&p you usually get what you get after you unmold it. I also suspect you used lavender-infused carrier oil as opposed to lavender essential oil? Essential oil does not add greasiness but for a batch that size I’d only add 3tsp. Lavender flowers infused into a carrier oil (like sunflower oil) is sometimes marketed as lavender oil. Use only a very little at a time if you add it to m&p soap. One teaspoon maximum I’d say.

  6. Hello,
    I have just started to cure my first batches. It is so exciting.
    Is it safe to cure them in the bedroom? My husband is worried about the lye which may evaporate into the air.
    Also if I don’t want them to go under 80g what weight should they have when I cut them?
    Thank you,
    xx

    1. Hi Edit, lye does not evaporate into the air so that’s not a concern. If you’ve used essential oils, then I’d say to keep them curing in a different room. The scent can be overpowering and too much for our systems if we’re in the same room for too long. Cold-process soap loses about half its water content after being cured so you’ll need to do your math :)

  7. Hi, I always find your post really helpful.
    Where I live is very humid and there are lots of dust in the air and the temperature is always above 85 F . So I it put the soap for cure close to a window, for air flow, even though is a window, there isn’t direct sun light. But Tom orden to prever the dust attach to the soap, (believe me the dust is really an issue here), I cover them with a fine mesh cloth, do you think that would be ok?
    Thanks in advance.

    1. I’m sure that it’s perfectly fine. Though I’d probably create a frame around the soap to drape the cloth over. The cloth might stick to the soap, depending on how moist the bars are after cutting.

  8. I was making soap and I am at the curing phase. I put them into a plastic box to cure is this a good idea or do I need to bring them out in the open?

  9. Hello! In regards to storing the soap for the 4 week period whilst it is curing, is it ok to store it in a cupboard that is a bit dark? There is plenty of air, but not so much light! Thank you!

    1. Dark is good, but the place needs to be open to the air. One of the points of curing is for water to evaporate out, and a closed cupboard is not ideal. It keeps moisture in adding to the cure time, and the moisture might collect in the wood inside the cupboard.

  10. I made a CP this past Saturday that almost immediately started gel phase – so i added more water so that I could just get it into the mold. Now it is still too gummy to unmold. Is this savable? I would love to rebatch but it is a gelatenous mess right now.

    1. If that happens again, don’t add extra water, just get it into the mold pronto! Your soap will eventually harden up but depending on how much extra water you added it may take weeks or months for it to evaporate out.

    2. Hi! Thank you for your advices!
      Is it okay to cure my CP soaps in an air-conditioned room 24/7 or in a closed closet with shelf?

  11. Can I cure my soaps in a shed outside during the winter? The humidity level is generally 45% or less and temps range between mid 30s to single digits negative.

  12. Hi there.
    I made a batch following your recipe “eco-friendly” CP soap with molasses added to color it. The thing is.. olive oil (I used refined one) wasn’t enough so I mixed about 30g of extra virgin olive oil instead. Plus I added 1/6 of more lye solution hoping it would help trace.. Now the batch doesn’t seem to be hardening in a mold. Is this batch useless at this point? If not, how longer should I cure it since it’s hardening very slowly?

    1. Hi Nat, it’s fine to use different types of olive oils for soap recipes but you shouldn’t have changed the lye amount. I suspect that your soap will be very harsh on your skin but you’ll need to run the exact recipe through the SoapCalc to know what the superfat is. As a beginner, please always follow soap recipes exactly to keep yourself and anyone who uses the soap safe.

      As for hardness — this recipe is high in olive oil and can take time to firm in the molds. Especially when additives such as molasses are introduced.

  13. Hello,
    I bought some Castile soaps a week ago and they are cured but When I used it, it formed a gel outside. The soap melted in 3 days of use’. Do you think that if I let them dry osome more months like 2 -4 months – these olive oil soaps will be harder?

  14. Hi Tanya;
    I have just started making soap, 7 batches so far. Two fails, but the rest are nice. My question is about putting soaps thru gel stage in the oven. I know that oven gelling keeps loaf soaps from having a center that is only partially gelled. Does gelling this way also help to shorten the drying time of our cold process soaps?
    I have really enjoyed reading and learning from your site. The small batch recipes do help you learn the process by doing new batches more often. That cements the routine and gives us confidence to try new things. So thank you for your teaching methods!
    Helen

    1. You’re so welcome Helen :) I agree about the versatility of small 1-lb batches when starting out, or experimenting. It saves a lot of worry and money, and encourages creativity! As for oven-gelling (or oven-insulating) soap — it may or may not affect the cure time, but the best thing to do to figure that out for the recipe you’re using is to weight the soap on a weekly basis after you begin curing. Once it’s not losing water weight any longer, it’s cured. I often oven-insulate my soap but placing it in a warmed oven that I then turn off. This is usually enough warmth and insulation to push the soap into gel phase. There’s also a process called ‘Oven-processing’ where you cook your cold process soap in the oven at a relatively low heat for up to an hour. The soap is called CPOP and may have less water and less curing time, but curing time will vary based on the recipe and other factors too.

  15. Do you use the same amount of timeCuring for the melt and pour soap or is it last time because you’re not adding more water

    1. Melt and pour soap does not need to cure at all and is ready as soon as it hardens. All it is is soap that’s been pre-made and pre-cured and mixed with a lot of additives (most not natural) that boost lather and make it meltable. You could use it as soap right out of the package it arrives in if you wish.

  16. Hello Tanya, I read somewhere if you add Rosemary essential oil to your soap and preserve it is this true ? I would like to have my soap cold process bars last as long as possible . I make cold process soap.

    1. You’ll have read that rosemary oleoresin (ROE) can extend the life of your soap. It’s not the same as rosemary essential oil and is used as an antioxidant. It can help slow the rancidification of free-floating oils but isn’t a preservative. In fact, preservatives aren’t necessary for soap because the microbes they’re meant to kill only grow in a more neutral pH with water. The best thing you can do to extend the life of your soap is to use ingredients that are well within their shelf-life — oils that have a year or more to go on their best-by date are the most important. If the olive oil you use to make your soap has a shelf-life of next week, then your soap will only be good until next week. Rancidification (going rancid) is what happens to oil and soap when they oxidize and this tends to happen when they are old.

  17. Hi Tanya, am from Nigeria, I just made my first bar soap ds for laundry use and when I was done mixing , the soap had a lot of lumps that is making d soap to have cracks rather than a smooth surface in the silicone mode I used. Please what do you think might be the problem?

    1. To troubleshoot what went wrong, go through the recipe again, making sure it’s accurate, then make the recipe again, double-checking all the measurements, temperatures, and that you’re using the correct ingredients. If you make it again and have the same issue then it could possibly be the fragrance, if you used it. Some fragrance oils can cause a lumpy effect called ricing. I’m not sure that’s what’s going on with you but it’s possible.

  18. Hi Tanya, thank you for your posts and all the useful information you share. I was wondering if you think it is possible to wrap the soaps with beeswax wrapping or do you think that would prevent moisture from escaping. Best wishes from North Carolina.

  19. Hi Tanya,
    Can i use fractionated coconut oil, or are using the more solid variety.? Also what does the grapefruit seed extract do? Is it to mainatin essential oil ?, could i make it without that? Also as i don’t have the castor oil and i saw on a saponification chart that it had the same number as shea butter could i just increase the amount of that?
    Thanks in advance,! Kate.

    1. Fractionated coconut oil doesn’t make the best soap, and it also has different saponification values so it would need a different amount of lye to convert it into soap. Stick with solid coconut oil for soap making, and get it from a soap making supplier if you can. The refined coconut oil is FAR cheaper than the pots of virgin coconut oil you find in shops.

      Grapefruit seed oil is an antioxidant — it helps free-floating oils (the superfat) in your soap to not go rancid. It’s optional, but if the oil you use is within six months of its expiration date the GSE may help your bars to last longer.

      Question on substitution of castor/shea oils — the short answer is no. Please read this to understand why, and how you can properly substitute: https://lovelygreens.com/change-customize-soap-recipe/

  20. Hi Tanya! Thank you very much for this useful information, however I had a question to ask. Recently I have been collecting some handmade soaps that were made by local sellers. Due to it’s nice scent and very cute shapes, I become attracted to the soaps but I didn’t want to use it as I like to display them as a decor instead. How long do these handmade soaps lasts without actually using them? or can you share any additional tips for me to keep the handmade soaps nicely in storage? Thank you and have a good day

    1. It depends on when they were made, how old the original oils were, and what oils (and other ingredients) were used to make them. Eventually, the scent will disappear in soap and you might begin to notice yellowy spots if the soap is high in oils that spoil/rancidify easily. I’d say an absolute maximum of two years but you’ll probably notice degradation within six months. My advice: use the soap and either buy more or learn to make them yourself. Leave bars that you’re not using out to look at but use them before they’re past their best. That way you can enjoy them without creating waste.

    1. If your soap smells bad, there’s something wrong and nothing you can do to disguise it. Besides, why would anyone want to clean themselves with something that’s unclean? Discard the batch and make it again with ingredients that are all within their best-by date.

  21. I just started making soap (M&P) and see that I’m going to have to graduate to CP or HP sooner rather than later. I haven’t found anything other than plastic to gift M&P soaps (for my own use, I can store them in air-tight jars)–and it’s so frustrating because I spent so much time carefully researching sustainable ingredients for the bars themselves. If you happen to know of a good alternative for M&P packaging, I would be happy to hear about it.

  22. Hi Tanya
    Amazing informational website – thank you so much!
    I have just made my first batch of olive oil castille soap (followed your recipe to the T) and taken it out of its bread mould. On cutting it was very flakey and broke rather than sliced?
    Would you have any tips on how it could be a bit more “elastic”. Unless this is normal of course.
    Yours greatfully
    Erin

    1. Definitely not normal Erin. Check all of your ingredients again first and make sure that the bottle of olive oil is 100% olive oil and not a blend. If there’s another oil in there then that could be the issue. Flaky and brittle soap can also be because of the soap being lye-heavy. Try making the soap again, double checking temperatures, ingredients, and weights, and you should succeed the next time :)

  23. Hi Tanya, I’m new to soap making, in fact I’m still waiting for some of my equipment to arrive before I can make my first batch. I have been reading your website avidly. There is so much information packed in it, and I am really enjoying it. Today I have a question for you. It is regarding the article on storing your soap, where you mention “and beauty documentation set up”. What do you mean by this? Do I have to provide ingredients lists to customers if I decide to sell the soap? Thank you.

  24. Very useful all the tips that you have left .. I live in a very humid geographical area, it is subtropical, and the truth is that the curing and storage is a headache .. Fan, air conditioning, dehumidifier, paper or plastic (the Vegetable paper is the best thing for me so far, I do not want to use plastic), once packaged, I do not know whether to keep it in a box or have it exposed since it has happened to me that they sweat and the paper wrinkles or stains …
    I have thought if you could adapt a soap recipe to these types of climates. Taking advantage of your soap making experience, what oils and shortening you recommend me to use more in the recipe … I would open some fats that will withstand more heat and humidity? I mean, be more stable …
    Your page seems amazing to me, I love it and I always consult it. Hug from the state of Entre Rios, Argentina

Leave a Reply

Your email address will not be published. Required fields are marked *

*

I agree