When making cold process soap, many soapmakers recommend allowing the soap to sit for 12-24 hours before cutting it into bars. This resting period is often referred to as “curing” or letting the soap “sit overnight.” But is it really necessary for cold process soap to sit before using? Let’s take a closer look at why soapmakers recommend allowing soap to sit before cutting, as well as the pros and cons of skipping this step.
Why Let Soap Sit Overnight Before Cutting?
There are a few main reasons why it’s commonly recommended to let cold process soap sit for 12-24 hours before cutting it into bars:
- To allow the soap to harden: When soap first comes out of the mold, it is still relatively soft and can be difficult to cut cleanly. Letting it sit gives the soap time to harden up before attempting to cut it into bars.
- To allow soda ash to appear: Soda ash is a white powdery deposit that can appear on the surface of cold process soap. It’s purely aesthetic and doesn’t affect the soap’s quality. Some soapmakers find it easier to remove soda ash after the bars have hardened up overnight.
- To allow the soap to finalize saponification: The saponification process takes 12-48 hours to complete. Letting soap sit gives the chemical reaction time to finish, ensuring the soap is at its mildest and most skin-friendly pH.
- To prevent cracks and crumbling: Cutting soap too early can cause cracks or crumbling along the cut edges. Letting the soap harden minimizes this from happening.
So in summary, the main reasons are to allow the soap to harden up, finish saponifying, and become firm enough to cut cleanly. Many soapmakers find their final soap bars have a more professional look and feel if they are patient and don’t rush to cut the soap right away.
Is Letting Soap Sit Overnight Completely Necessary?
While letting soap sit for 12-24 hours before cutting is recommended, it isn’t always a hard and fast rule. Some soapmakers will cut their soap after just 4-6 hours, especially if they are using individual molds. Here are some pros and cons of cutting soap without letting it sit overnight first:
Pros:
- Can get the soap ready faster
- May prevent extreme soda ash
- Can start using the soap sooner
Cons:
- Soap may still be too soft, making cutting difficult
- Cut edges may crack or crumble more easily
- Bars may not release as cleanly from the mold
- Soap may not be fully saponified yet
Individually molded soaps tend to harden up faster than those made in a loaf mold, so they are often easier to unmold and cut after just 4-6 hours. However, the soap may still be somewhat soft or sticky. Letting it sit for the full 12-24 hours helps ensure the soap is fully hardened and ready to use.
Tips for Cutting Soap Early
If you do decide to cut your cold process soap before letting it sit overnight, here are some tips:
- Use simple individual molds rather than a large loaf mold. Smaller soaps will harden faster.
- Chill the soap to help it harden faster before cutting. Place it in the refrigerator for an hour or so.
- Use a very sharp non-serrated knife and cut in one firm, decisive motion.
- Dip the knife blade into rubbing alcohol frequently so it glides smoothly without dragging.
- Don’t handle the cut bars too much until they harden up more.
- Let bars sit for 4-6 weeks to fully cure before using, even if cut early.
Cutting soap early takes precision and care to get clean cuts without crumbling. But with the right strategy, it can work in a pinch!
What Happens If You Don’t Let Soap Sit Overnight?
If you choose not to let your cold process soap sit at all before cutting, here is what you may experience:
- Very soft soap that squishes when you try to cut it
- Messy cuts and misshapen bars
- Soap sticking to the knife blade
- Cuts and edges crumbling as you handle the bars
- Bars not releasing cleanly from the molds
- An uneven, unprofessional bar shape and texture
- Soap not fully saponified, may still be lye-heavy
While soap can certainly be cut right after it’s unmolded, the results are often messy and disappointing. The soap needs a few hours to start hardening up before it can be cut neatly. Trying to rush the process usually doesn’t work well.
Recommended Time To Let Soap Sit Before Cutting
Based on most soapmakers’ experiences, here is the generally recommended time to let cold process soap sit before cutting:
- Palm-free recipes: 18-24 hours
- Recipes with palm oil: 12-18 hours
- Individual cavity molds: 6-12 hours
- Loaf molds: 18-24 hours
Palm oil makes the soap harden significantly faster. Loaf molds also take longer to harden up and release cleanly than individual molds. Play around with different rest times to see what works best for your specific recipe and mold.
Can You Skip Letting Soap Sit in the Oven Process?
The oven process method involves putting cold process soap in the oven immediately after pouring it into the mold, to create a “hot gel” phase. This accelerates saponification and can allow oven process soaps to be unmolded and cut more quickly.
However, oven process soap still benefits from a sitting period before cutting. Some guidelines:
- Let cool completely after removing from the oven before cutting
- Refrigerate for 1 hour after cooling if using loaf molds
- Let sit at room temp for 3-6 hours if using individual molds
- Cut carefully with a sharp knife dipped in alcohol
While the hot gel phase means oven process soaps can technically be cut earlier than cold process, a sitting period is still recommended for the best results.
Conclusion
Letting cold or oven process soap sit in the mold for 12-24 hours before cutting is best practice for most soap recipes and mold types. However, soapers using palm oil or individual molds may be able to carefully cut some bars earlier. There are pros and cons to cutting soap without letting it sit overnight first. Being patient usually results in nicerlooking, longer-lasting soap bars, but it’s not strictly required. With care and precision, soap can sometimes be cut after just 4-6 hours. Just don’t expect the prettiest results if rushed.