Consistency is Variable with Liquid Castile

Liquid Castile Soap Dispenser

Liquid castile is a wonder, which is why sales keep growing. Not only does it have lots of uses as it is, but it can also be other things entirely.

Unlike bar soap, castile is a finished product that can still be changed. The most obvious change is adding scent. Less obvious is changing its consistency to turn it into products that can seem completely different.

Diluting Castile

One of our earliest liquid soap customers was an auto detailer from Texas. He bought our foaming soap, and while we weren’t looking, started experimenting with consistency till he found a sweet spot in the balance of soap and water. When he did, he called us to say he’d found the best glass cleaner he’d ever used.

We’ve found the same thing to be true in our own homes. The key is exactly what our Texan customer said, the right balance of soap and water, not only for glass cleaner but for foaming soap and overall spray cleaners, too.

As we discovered when we introduced our foaming soap, straight castile is too thick to work well with foaming tops. But if you dilute castile in the ranges of 50-70% soap to 30-50% water, and you tweak the consistency to work best with your particular foaming top, you wind up with a mixture that foams well but doesn’t plug the dispenser.

For a glass cleaner, the ratios lean heavily on water, 5-15% soap to 85-95% water. The ranges are as wide as they are because not all castile soap is the same and the best balance is just enough water to not leave streaks on glass.

Spray-cleaner ratios are more variable. Depending on the surface, and how much rinsing you’re able to do, percentages can range widely between the ratios for foaming soap and glass cleaner.

Rows of bottled liquid castile soap lined up on a self.

Thickening Castile

Castile, in general, is thinner than many people like. For those people, and for our customers selling to those people, there are ways to make it thicker. If you Google thickening Castile soap, you’ll see lots of options, salt and a salt-water solution being the most common. We chose to use organic guar gum, available locally in many places, but easily available online.

We have four consistencies available in our custom/bulk division that are thicker than the castile on the web site. These certainly aren’t the only viscosities available, though. We chose four to (1) keep the number of possibilities down, and (2) to meet market expectations for familiar product names like hand wash and shower gel.

The real possibilities for viscosity are many. If you’re looking for a slightly thicker consistency than standard castile, the consistency of milk, for instance, you can add as few as 10 grams of guar gum per gallon of castile. If you’re looking for a shower-gel consistency, you can add as many as 40 grams per gallon. Within those parameters, the best consistency is really a matter of preference.

As Always

As we mentioned in our blog about scenting castile, mixing thoroughly is a big deal. The consensus among soapmakers is you can never stir soap enough, and the best tool for mixing is a good stick, or immersion, blender.

The other element of mixing is heat. You don’t need to heat castile to dilute it, but for ingredients other than water – essential oils, organic guar gum – heating the castile to around 120 F before mixing makes the process go better. One tip you’ll find for adding guar gum, to avoid clumping, is to wet it with vegetable glycerin prior to adding it to the soap, so it’s no longer a solid, but more like honey. Vigorous mixing will work also, but wetting the guar gum first can reduce the amount of vigorous mixing you’ll need to do. Another consideration is the efficiency of the mixing process. High-RPM or high-shear systems require less guar gum and less mixing time to achieve the desired thickness.

Update on Castile As It Is

We know castile can be several things, but the uses for liquid form as it is keep growing. Since we published the first blog in this series, we’ve made an impressive home-based discovery. Our castile, straight from the bottle on a sponge, cleaned grime from the bathtub that several applications of a leading natural tub and tile cleaner didn’t. We put the leading cleaner away.

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