Lye pockets in soap can occur when a batch of soap separates. This separation can be due to overheating, insufficient mixing, or misbehavior caused by a fragrance or essential oil. The result is typically a separated layer of oil and glycerin and, possibly, a heat tunnel exhibiting lye pockets in soap.
Safety first: when dealing with lye pockets in soap, long sleeves, eye protection, and gloves are important. If a soap is leaking oil and glycerin, there is a chance it could be leaking lye water as well. The best option is to dump it into a slow cooker set on low and allow it to fully cook and blend together in the pot. This Hot Processing Method will take two to three hours, and when finished the soap will be somewhat translucent and the consistency of oatmeal. If the soap is too dry, the texture may be more like mashed potatoes. Create a more liquid batter for pouring by adding two tablespoons of yogurt, milk or cream, or any other liquid of your choice such as aloe juice, coconut water, or tea.
Lye pockets in soap can usually be prevented by using a tried-and-true fragrance, soaping at cool temperatures, and blending to at least a full, thin trace with the immersion blender. Blending until the thinnest possible trace is reached is often preferable when creating complex swirl patterns and soap designs. However, it is important that the soap has been blended enough to jump start the fatty acids to link into chains, causing the soap,oil, water, and lye to emulsify and then to thicken.
Lye pockets in soap need not be written off as a failed batch and discarded. A secondary cook via the Hot Process Method can save a soap that has separated, but contains all of the needed ingredients. Learn about rebatching soap to save failed recipes.
Spice essential oils, such as cassia, cinnamon, clove, and ginger can cause soap to heat up quickly when used in large amounts. This heating has the potential cause separation, cracking, or heat tunnels with the potential for crystallized lye pockets inside. For best results, allow the soap to sit at room temperature and gel on its own. Once gel stage is fully reached, put the soap in the refrigerator to discourage further rises in temperature.
Floral fragrance oils are also notorious, both for acceleration (causing soap to set up more quickly) and for heating up. An added drawback to this heating is that floral oils are quite complex, and some of that complexity can be burned off if a soap’s temperature rises too high. For these reasons, I recommend placing floral soaps immediately into the refrigerator or freezer to prevent gel phase completely. This will preserve the fragrance and prevent the heating that can cause separation.
Recipes that are high in palm oil or stearic acid can heat up quite a lot in the mold. To prevent problems, do not use more than 0.5 percent stearic acid per weight of base oils in your recipe. In addition, be sure to melt your palm oil completely and stir well before each use, as the natural stearic acid content tends to sink to the bottom of the container, creating an ever-increasing amount of stearic acid in your soaps as you use up the palm oil.
Recipes that contain honey or other sugars as soap ingredients will heat very readily. Never use more than one tablespoon of honey, sugar, maple syrup, agave nectar, etc. per pound of base oils. So, a three pound loaf of soap contains about two pounds of base oils, and therefore would use no more than two tablespoons of sugar substance. If you use too much sugar, the soap recipe can seize, or superheat and burn the sugars.
We should all be so lucky as to never have separation with lye pockets in soap. Those of us who make complex swirls with multiple colors using very thinly traced soap are at risk, because the thinner the trace, the less emulsified the soap batter has become. Not enough mixing can lead to lye pockets in soap. In addition, any set of circumstances that causes a soap to heat up during saponification can create the perfect environment for lye pockets. Possible risk factors include untested fragrance or essential oils, or the use of sugars in the soap recipe. For best results, always read reviews of soap scents before using so you will know what to expect. Never add more than the recommended amounts of sugars or other additives to the soap. And always make sure than your thin trace is truly a trace.
Have you ever had lye pockets in soap? How did it happen? What did you do to save the soap? We would love to hear your experiences.
Resident soapmaking expert for Countryside Network, longtime saponifier and craftsperson Melanie Teegarden sells her crafts at from her Althaea Soaps website.