Sunday, February 19, 2006

Soap Experiments

Being one to try to push the rules a little, I decided to try an experiment with soap. First I should say that I've been making soap for ten years. When I started, the instructions were very exact. You had to make certain the temperature of the melted fats was the same as the temperature of the lye water. Instructions said to use hot and cold water baths to get them to 95F or 100F, and all the instructions I found said they had to be the same. After pouring the soap into the moulds, you had to insulate it with a pile of blankets, and don't move it or even peek under the blankets at it. If you didn't take care to fiollow the rules of this exact science, you would have a failed batch on your hands.

Quite some time ago I made soap with fats at somwhere around 100F and I mixed in the the lye water as soon as it had cleared, I'd have to go back through old files, but it was likely somwhere around 160F or so, but I don't recall. I just know I didn't wait for it to cool down even a bit. I didn't add fragrance, because that can definitely cause problems at that temperature. After pouring it in a wooden mould, I wrapped it up in blankets and the next day, when I unwrapped it was beautiful. After it had cured, terrific. Now I wouldn't do it if I were adding and fragrance as I said, because they can cause problems when the temperature is over 100F. Nor would I do it when using essential oils, because I think it would "burn off" some of the properties of the essential oils and some of the scent. But it's nice to know that the old rule of exactly the same temperature isn't set in stone. I usually aim for the fats being around 100F and the lye water can be as low as room temperature, and that's what I've done for years now.

Another question I had was what happens if you don't pour it right away at trace, but continue stirring. I had heard your soap could turn out kind of crumbly. I decided to try it using the hand blender and to take the soap to a trace, then zap it more with the hand blender. Okay, that does cause problems. It came out really grainy, or chalky, like the whole bar was soda ash.

For quite some time I've barely insulated soap. I cover it in plastic and put a towel over it, which prompted my most recent experiment. I have to say, I like the look of soap if it hasn't gone through the gel phase. You know how if it's really heavily insulated it gets to look like it's melted in the mould? Some fragrances will heat it up to over 160F in the mould even it it's not insulated. It doesn't hurt the soap, I just like the look of the soap when it hasn't got that hot in the mould. So I got a fragrance that I knew caused the soap to gel in the mould, even when it isn't heavily insulated. I made my soap, added the fragrance, put on the plastic wrap and put it in the fridge. I looked at it several times and felt the bottom of the mould and it did warm up, but not to the gel phase. When took it out the next day, the soap was fine. It was quite hard when I tried to stamp it, but that aside, there was no apparent difference. If I were doing it again I wouldn't use plastic wrap, I'd just cover it with a tea towel to prevent anything falling on the surface of the soap. There were some drops of water on the underside of the plastic that fell onto the soap leaving round drop marks on the surface.

It's kind of fun doing something a little different. When I'm testing fragrances for our line, I always do exactly the same recipe, exactly the same way so I know what to expect. Some fragrances have required many samples to be tested before we found exactly the right one. Green tea is a good example, I tested thirty six different samples from perfumers before I found one that worked right and that smelled exactly how I thought a green tea fragrance should. It can get routine. So doing something a little more gourmet, like making my Mango Butter soap, which turned out awesome, is fun. I must have checked it while it was in the mould almost every half hour.

Years ago, in an experimental moment, I tried making soap with butter. It's a fat, why not? It worked, but it smelled disgusting, but I won't go into that story.

Happy Soaping.

Thursday, February 09, 2006

Why do my colours bleed?

I'm asked this question frequently, so I thought I'd address it here. This is more of a problem with melt & pour soap than with cold process. It's also only a problem with the dyes, not the pigments. So, that having been said, why?

They both colour the soap differently. The dyes are water soluable, they dissolve in water. The pigments (and micas) are water dispersible, so they disperse in water. Picture this. You add a spoonful of sugar to your tea and stir it, the sugar dissolves. Then you add a teaspoon of sand to your tea and stir it, the water disperses, but when you stop stirring, the sand settles, it won't dissolve in water. That is the difference between the dyes and the pigments.

The dyes, when added to melt & pour soap, dissolve in the water in the soap, but when it's touching a layer with a different colour, they mingle. Even more so if the soap is hot and starts to melt the first layer.

The pigments are teensy weensy rocks, and as your soap hardens, the "rocks" are trapped throughout the soap, but never dissolve. As you use the soap, the "rocks" rinse away (and sometimes leave colour on the washcloth temporarily).

Personally, I like working with the pigments more than the dyes. The colours stay true. I do find though that in melt & pour soap, there will always be some sediment from the pigments in the bottom of the soap pot, that has settled. No matter how long I stir or how cool the soap gets before I pour it, there's still a bit of settling, so the last wee bit with the sediment gets tossed, but it's only about a half a teaspoon.

The advantage to the dyes is the more vibrant colours, because they're synthetic. The pigments are muted colours, more like nature's colours. The other advantage is the clarity in transparent soap. The dyes don't effect that at all, while pigments, because they're those teensy weensy "rocks" will have some affect in the clarity.


While I'm on the topic of colours, another frequent questin is about the FD&C or FD in the names of the dyes. FD&C means it is approved for use in food, drugs & cosmetics, the D&C means it's approved for use in drugs and cosmetics only.

If you have any other questions about the colourants that you'd like to ask, leave them in the comments and I'll do my best to answer them.