Guest post by Mrs Redboots
Cooking Fat and Drain Cleaner
Whenever anybody asks me how I make soap, my invariable response is, “Oh, it’s just cooking fat and drain cleaner”. Which is absolutely true, and it never ceases to amaze me how just a few common items can become wonderful soap.
I usually make soap twice a year, in April and October*, and usually make goats’ milk soap and lavender soap, because they’re my favourites. This lot, however, was made as barter for a friend, who is making me a new skating dress in return, and she wanted sandalwood, so I bought some sandalwood essential oil, and began.
You start by melting the fats together,
and dissolving the caustic soda in some solvent – water, in this case, but I do use goats’ milk for the goats’ milk soap.** You could use other liquids, too – I never do, but I have seen recipes for soap made with pureed strawberries (made up to the right amount with water, of course), and I think once when I was starting out, I made a soap with coffee, and added the grounds later – this was supposed to be a “gardeners’ soap”, but I didn’t like it much.
This soap wasn’t coloured, but you can – there are various artificial dyes out there specifically for soap-making, I believe; I’ve only ever used something called alkanet root – you soak it in the oil and it goes bright red, and then when you add the caustic soda it goes blue, as it’s a litmus indicator. It settles out as a sort of bluish-pink, perfect for my lavender soap!
I always use a cheap “filler” oil – Trex or Purina or very similar – for the bulk of the fat, then ¼ coconut oil, as it makes a lovely lather. Then I like corn oil for the last quarter, but of course, olive oil is good, too. The soap-making “guru” Melinda Coss doesn’t like the kind of soap corn oil makes, but I do. Of course, you could make your soap with any oils or fats you liked – imagine a whole soap made of extra-virgin olive oil*** – all you have to know is what’s called the saponification value of the fat in question, so you know how much caustic soda to add. There are various tables out there on the Internet where you can enter the various amounts of fats or oils you’re using and it calculates the amounts for you, or you can do it by hand using the tables in the back of a manual. My manual was Melinda Coss’ “The Hand-made soap book”, but there are others out there.
You have to be very careful with the caustic – this is in the sink, as I have a nasty scar on my arm caused by not having been careful with the caustic. We will not talk about that.
Vinegar can help neutralise it, so always keep some within easy reach in case of accidents. It also helps, incidentally, to add some to the washing-up water when you’re clearing away afterwards.
Once the melted fats and the caustic solution have cooled down a bit, you mix them together
and then whisk
until it is thick and creamy (a stage known as “trace” because your whisk leaves a trace on top of the soap.
Then you add the essential oils, if you’re using them, put it into moulds^
and into a warm place,
covered with a towel, to cook. Well, to saponify, if we’re being technical.
Here’s a sneak peek of it cooking. Note how it has generated enough heat to melt itself in the big mould:
Once it has cooked, you let it cool, and I find it makes a better quality soap, for some reason, if you then freeze it. It certainly makes it easier to unmould! Don’t ask me why….. So you unmould it 
and cut it up 
and let it dry for (ideally) a month before wrapping and giving it away^^.
Sometimes it boils over, and you have odd jagged bits of soap that have slid down the outside of the bottle – not this time though. When that happens, I chop them up very fine and add a little boiling water to melt it again, and remould it; it’s usually not nice enough to give away, but fine for family use!
This time, though, I had a half-hearted heart left over, and couldn’t resist washing my hands with it!
The brown streaks on the finished soap do fade as it dries out.
It’s lovely!
And isn’t it typical that this particular soap knew it was being photographed and was incredibly well-behaved? It didn’t boil over in the airing-cupboard (I have to sit it on a tray, in case it drips on to other people’s clean laundry on the shelf below). It didn’t refuse to saponify, and end up a nasty mess. It didn’t even have ominously harsh gel bits at the bottom of the mould as sometimes happens. It simply behaved itself and turned into quite beautiful soap!
Two weeks later, and here is is almost ready to give to my friend:
When, that is, she has finished making my skating dress for me!
By the way, if you don’t fancy faffing about with caustic soda and so on, you can buy pre-made soap base and experiment with all sorts of colours and shapes and so on. I tend to compare this to making a cake (as in making your soap from scratch) or decorating it (as in using the soap base for a starting-point). Both good, but different people suit different types!
* * *
*In time to throw for people for the major international competitions we go to, and to use as Christmas cards (saves forgetting people!).
** You don’t say!!!
*** Winces at the thought of the cost.
^Yes, that’s a 2-litre water-bottle with its lid cut off. Works well, and you have guidelines to show you where to slice the finished soap.
^^ You aren’t allowed to sell it in this country without having to jump through so many Health and Safety hoops that really, you have to do it professionally to be worth it. So I don’t sell it. Nobody said nothing about barter, though….
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