Sodium lactate is a clear liquid salt naturally produced by the fermentation of sugars found in corn and beets. It is used in a variety of bath and body products such as lotions, shampoos and soaps, and is a natural humectant and wonderful moisturizer.
In cold process soap it helps to harden the bar which allows for quicker unmolding – this is very helpful when you’re working with a soft soap. Sodium lactate can also help stubborn soap release from molds that don’t require lining, such as plastic or silicone. Additionally, it gives the soap a creamier look and lather, and helps the soap last longer in the shower.
Usage rates differ among manufacturers, but a normal range is usually 0.5% – 4% per pound of oils. Start out by testing a small amount and work up from there. Too much can cause the bar to become crumbly – I’ve heard of some soapers successfully using the highest rate while others were not so successful.
Sodium lactate is easy to use. Just add it to the cooled water/lye solution and then make the soap as you normally would.
My Experience With Sodium Lactate
Soap that would take 4 days to unmold is cut in half when I add SL. I use 3% in my test batches and really like the added moisture and creamy look of the soap. It adds a lot of lather and bubbles too. In fact, I can even omit castor oil for lather because sodium lactate does such a great job. It does extend the life of the soap a little – maybe a few days to a week at most. Although I like using SL, I may just utilize it when working with olive oil soap when I don’t want to wait several days to unmold.
If you want a harder bar of soap you can simply change up your recipe by adding hard butters or doing a water discount. Sodium lactate isn’t necessary in soap making but it can be helpful. It’s inexpensive and can be purchased through most soap supply companies. Give it a try and see if you like it!