Recently I made a batch of soap in an attempt to make some soap that I can use with my straight razor. The previous batch I had made was REALLY soft and wasn't going to work so I decided to try and make a nice hard soap. It turns out that the lather made this recipe isn't very stable so I will have to make a new batch and try a different mixture. However, I also discovered that hard soap may not be the best, but I will point out a few pro's and con's that I discovered and it may help you make a decision.
Pro's. One of the biggest benefits of the hard soap is that it lasts a long time. This soap doesn't crumble or fall apart and even stays together pretty well when it gets wet. Because it holds up well when it's wet it doesn't clump into your shaving brush like a soft soap might. Sadly, this is about the only pro's I could find to simply a hard soap. At first I honestly thought this would be a big bonus so I wouldn't have to make a lot of it.
Con's. The biggest benefit might also be its biggest downfall. Because it is so hard it is difficult to lather. It is hard to dissolve enough soap to get it to lather and so it takes a long time. That wouldn't be so bad if the lather was good, but it just might be what makes it unable to produce a good lather. Also, being so hard also makes it hard to even use as a hand soap and can even be kind of painful.
So, there you have it. It is really short but I hope it helps. When you are making a soap keep in mind that a hard soap might last a while and hold up well when wet, which is good, but it may be impractical in the end. The one benefit is that I might be able to mix in more potassium hydroxide, typically used in liquid soap, and get a better lather without making mushy soap.
Saturday, June 15, 2013
Wednesday, March 6, 2013
Potassium Hydroxide VS. Sodium Hydroxide in soap making
If you're fairly new to soap making, like me, you might be wondering if you could interchange potassium and sodium hydroxide. The answer is depends. It depends on what you are looking for in your soap and if you are prepared to deal with outcome.
First you need to know a little about soap making history to help you in your decision making processes. Back when soap making started there were probably as many opinions about how it should be made as there were families. One of the most common was to make soap was with ashes from a fire that were boiled. Boiling the ashes of a fire, particularly hardwood, would produce pot ash or potassium hydroxide. The potassium hydroxide was the active ingredient that would help saponify the oils and fats (saponify, or saponification, is a more recent term meaning to turn into soap.). A lot of these older recipes used different techniques to tell when you had reached saponification, but there was no numerical standard.
More recently scientist have continued to do what they do best, experiment, and have produced saponification tables for different oils and fats. These tables show how much lye, or sodium hydroxide, is needed to saponify the specified oils and fats. Some tables are in grams and some in ounces. To make this process even easier, so you don't have to do it by hand, some websites provide a "lye calculator" that adds up the amount of lye you need to saponify the oils you choose. It is truly much more simple today than it was in the days of the pioneers. Still, there are some questions that aren't easily answered.
If you are like me and have some background in chemistry, but not in soap, you might think that this process is similar to polymerization and that the only part that really matters is the hydroxide. The truth is that saponification is dependent on the hydroxide but also acts as a salt. Therefore, you will get different results depending on which hydroxide you use. Typically you will get a harder soap from sodium hydroxide than from potassium hydroxide. Older recipes that used pot ash would typically have you add salt, sodium chloride, to harden the soap. One other difference is that you tend to get more lather from the potassium hydroxide than the sodium hydroxide.
I want to make a shaving soap and do it all myself. I have read several different articles and a lot of them seem to mention that there is potassium in shaving soap because it helps give a better lather, but none of them seem to mention the softer soap. I tried using just olive oil and used 100% sodium hydroxide, 50% sodium hydroxide 50% potassium hydroxide, and 100% potassium hydroxide in three different batches. The first batch was a little soft but hardened up after some time curing, while the second batch was like mush and the third just stayed a liquid. It turns out that olive oil produces a soft low lather soap anyway, which made it less than ideal for my test, so it was hard to get it to lather. However, even with the low amount of lather I noticed that the 50/50 mixture produced a better lather than the 100% sodium hydroxide.
So if you want a bar of soap you should probably stick to sodium hydroxide, but if you want a liquid soap us potassium hydroxide. However, if you are looking for lathering characteristics look first at the properties of the oils, because that will make your biggest difference, and then pick your hydroxide. I personally will be experimenting more with a blend of the two and trying different oils to produce the best lather for shaving. I hoped this helps.
First you need to know a little about soap making history to help you in your decision making processes. Back when soap making started there were probably as many opinions about how it should be made as there were families. One of the most common was to make soap was with ashes from a fire that were boiled. Boiling the ashes of a fire, particularly hardwood, would produce pot ash or potassium hydroxide. The potassium hydroxide was the active ingredient that would help saponify the oils and fats (saponify, or saponification, is a more recent term meaning to turn into soap.). A lot of these older recipes used different techniques to tell when you had reached saponification, but there was no numerical standard.
More recently scientist have continued to do what they do best, experiment, and have produced saponification tables for different oils and fats. These tables show how much lye, or sodium hydroxide, is needed to saponify the specified oils and fats. Some tables are in grams and some in ounces. To make this process even easier, so you don't have to do it by hand, some websites provide a "lye calculator" that adds up the amount of lye you need to saponify the oils you choose. It is truly much more simple today than it was in the days of the pioneers. Still, there are some questions that aren't easily answered.
If you are like me and have some background in chemistry, but not in soap, you might think that this process is similar to polymerization and that the only part that really matters is the hydroxide. The truth is that saponification is dependent on the hydroxide but also acts as a salt. Therefore, you will get different results depending on which hydroxide you use. Typically you will get a harder soap from sodium hydroxide than from potassium hydroxide. Older recipes that used pot ash would typically have you add salt, sodium chloride, to harden the soap. One other difference is that you tend to get more lather from the potassium hydroxide than the sodium hydroxide.
I want to make a shaving soap and do it all myself. I have read several different articles and a lot of them seem to mention that there is potassium in shaving soap because it helps give a better lather, but none of them seem to mention the softer soap. I tried using just olive oil and used 100% sodium hydroxide, 50% sodium hydroxide 50% potassium hydroxide, and 100% potassium hydroxide in three different batches. The first batch was a little soft but hardened up after some time curing, while the second batch was like mush and the third just stayed a liquid. It turns out that olive oil produces a soft low lather soap anyway, which made it less than ideal for my test, so it was hard to get it to lather. However, even with the low amount of lather I noticed that the 50/50 mixture produced a better lather than the 100% sodium hydroxide.
So if you want a bar of soap you should probably stick to sodium hydroxide, but if you want a liquid soap us potassium hydroxide. However, if you are looking for lathering characteristics look first at the properties of the oils, because that will make your biggest difference, and then pick your hydroxide. I personally will be experimenting more with a blend of the two and trying different oils to produce the best lather for shaving. I hoped this helps.
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