I developed this natural deodorant recipe to be nice and solid. I was tired of natural deodorants melting when things were too warm. This recipe will not! This recipe is not hard to make. It's all about balance. Too much oil and it can melt. Too much wax and it can be tacky.
When melted, add the arrowroot powder and baking soda a little at a time. It may want to clump up on you, but just keep stirring. It helps to keep the natural deodorant recipe mix on the double boiler so it doesn't start getting cold.
Allow to cool naturally, do not place in the refrigerator. This can cause moisture on the surface this natural deodorant recipe and could also cause it to become soft when it comes to room temperature.
Not all beeswax is created equal. Some are harder and drier while others, with more moisture, are softer. If you follow this recipe and still have a softer bar, then you may need to add more wax. Try melting the bar down, adding a tablespoon more wax, then remolding it. This should be enough, but you may need to play with it a few times to get it right. Remelting the bar, even a few times, will not affect the quality. Be sure to stir it well each time.
If you don't want to use baking soda, you can use bentonite clay instead. Some people are opposed to baking soda and some find it causes a rash. It is a salt, after all, and probably dries out the underarms a lot. Also, there is no real proof that baking soda does actually absorb odors. If you choose to not use it, there are alternatives.