Milling Homemade Soap

Sometimes when we make homemade soap, we find milling necessary. Milling is a fairly easy way to improve the quality of homemade soaps, either to save a bad batch, or to improve a mediocre one.

We once made a batch of animal fat soap with our neighbors. Like us, they usually use vegetable oils in their soaps, but they had rendered some mountain goat fat  and wanted to use it. We were eager to try it as well, so we used the fat as one of two oils in the recipe.

When we added the lye, the animal fat saponified much faster than the vegetable oil, leaving the mixture flaky. The result worked well as soap, it just didn’t look or feel very nice, so we eventually decided to mill it.

This is how the soap turned out originally, clotted and grainy. Milling smoothed it out nicely (Photo: Mark Zeiger).

Milling soap has a couple of advantages. It smooths the texture of the soap, and provides better opportunities for creativity, because the saponification process has passed. That means that it can be reprocessed at lower temperatures. Since some essential oils don’t do well in high heat, they can be added during milling, making the soap more fragrant. This is also a good time to add scrubbers or other additives that might have interfered with the saponification process in the original batch.

We shredded the cakes with a kitchen grater. We then heated the shredded soap with a little bit of water, stirring occasionally until it reached the “trace” stage. That’s when a drizzle of melted soap over the rest of the pot leaves a trace for a bit before reblending. Once we achieved that, we poured the soap into molds and continued as we would with a fresh batch of soap.

This made a much smoother soap with just enough added essential oil to bring out the fragrance. What we’d thought would be a chore turned out to be fun. We ended up with perfect soap rather than just “making due” with what we had at first.

Our most recent soap batches are just about cured. We’ve trimmed the bars a lot. We could use the trimmings for bathing, but we’re thinking of milling them into additional bars instead.