About this blog

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Wales, United Kingdom
In autumn 2010, my husband Ian and I both quit our jobs, sold our house and left the flatlands of the east for the mountains of Wales. Our goal is to create a more self-sufficient lifestyle in a place we actually like living. Whilst Ian will continue to earn some money as a freelancer, my part of the project is to reduce how much we spend by growing and making as much of what we need as possible. The purpose of this blog is to keep friends updated with how the grand project is progressing, but all are welcome here. If you're not a friend already, well perhaps you might become one.

Thursday, 14 July 2011

Leftover soap

This is not a post about bits of soap that are left over from nearly using up a bar, but soap that is made from leftovers. I've been saving meat fat for some time now. I was using it for cooking to start with, then it occurred to me that it would be healthier to cook with oil and make soap with lard, rather than vice versa. I've been saving it up for a while, and the little pots are cluttering up my fridge.

Two pots of chicken fat, two of lard, and one of lamb tallow, which turned out to have lard in the bottom as well.

As you can see from the picture, whilst this stuff keeps fairly well, it's not perfect and there are little bits of mould that needed scraping out before I used this. Some of this has probably been in the fridge for well over a month.

I looked up the sap values* and found that for these three fats the values were all the same, which meant I could mix them and weigh the whole lot together, reducing the inaccuracy of weighing lots of small amounts. Having weighed that (pretty much exactly 1 lb in total), I added a bit of hemp oil (2 oz) that I still had in the kitchen, untouched since last time I made soap.

I then turned to a couple of online calculators to work out the final details of the recipe. This one has a neat little adjustment where you enter the size of the mould you're using and it resizes the recipe to fit. Using these, I added a bit of sunflower oil (1 oz) and tweaked the superfatting** adjustment to 7% so that I'd get a nice round number for the quantity of lye required (2.5 oz). Just for completeness, the amount of water in this recipe was 5.8 (a slightly generous 5 3/4) oz.

Having settled on the recipe, I put all the fats and oils in a big bowl*** and put that in the oven, which was still hot from bread-making, to melt the meat fats. While that was melting, I weighed the water into a plastic jug, carefully sprinkled the required weight of caustic soda into that, then took it outside so it could give off noxious fumes into the atmosphere rather than my kitchen.

When the fats were melted, I took them out of the oven and scooped off the small amount of scum that had floated to the top. Hmm, that could be a drawback of using saved fats. I may not have got quite all of the bits out, but still, I'd have plenty of time to fish them out while waiting for the mixture to trace.

Melted meat fats, looking an uninspiring brown colour

Being rather less nervous about the whole process the second time around, I may not have waited very long for the two liquids to cool down before mixing them together. I did, however, follow John Seymour's advice and added the lye very slowly to the fats, stirring as I did so. The fats started to change colour immediately.

What amazed me was how quickly this reached the trace**** point. I didn't time it, but it seemed barely five minutes before I saw the first signs of it, and not more than twenty at most, before it was definitely tracing. I didn't even use a blender - I was stirring with a good old-fashioned spoon. Forget your fancy Castile soaps, this is the way forward!

Somewhat less than 24 hours later (i.e. this morning), I turned the soap out of the mould and cut it into blocks.

Ten small bars of meaty soap

It was very soft when I turned it out, but it's hardening (and getting paler) with each hour. Just in case you were wondering about the smell (and I suspect you were), it smells lovely! Not at all like meat, just very soapy. Now, does anyone know how long lard soap takes to cure?


* Saponification values, that tell you how much lye to use for a given amount of fat or oil.

** The amount by which you adjust the quantity of lye in the recipe, to be on the safe side, i.e. erring on the side of a sloppy mess rather than something that'll eat through your skin.

*** Last time I used a bowl that was only just big enough to hold the oils, which made it difficult to mix without sloshing over the edge. I learnt from that mistake and used a very big bowl this time.

**** When moving a spoon through the mixture leaves a 'trace' behind in the surface. This is the sign that you can stop stirring and pour the soap into a mould.


  1. Holy Moly! I am duly impressed, and totally shocked that it doesn't smell like leftovers from the bbq.

    I have toyed with the soap making idea but always shied away because it seemed so difficult, but maybe I'm wrong? I am of the vegetarian persuasion though, so no meat fats to save... Still I wonder how the cost of buying the ingredients would compare to the cost of buying soap. Hmmm... thoughts to ponder...

  2. I was pretty scared of soap-making before I tried it, too, but I found it's really not that difficult after all. There are plenty of websites for guidance, and you just have to take basic precautions to make sure you don't get caustic soda on your skin.

    I worked out some costs when I was using the soap for laundry liquid (http://growingthingsandmakingthings.blogspot.com/2011/03/laundry-gloop.html) and it's pretty cheap if you use ordinary cooking oils, rather than more specialist ingredients (I have no idea what it would cost with those - I didn't look it up).

    I calculated the cost based on not-the-most-expensive olive oil, which makes very fine soap, though you will be stirring for a very long time if you choose this oil ;-)

  3. Soapmaking rocks! Sorry, showing my bias. If you really want to do this "vegetarian", the easiest way (not having to order special oils) would be to use shortening. The recipe and results would be very similar, just check the lye calculator to make sure your lye measurements are good.
    As far as cure time goes, I am a very impatient soaper, and have never waited the 10 to 12 weeks that some recipes call for.
    In "the old days" when we were making our own lye in ash barrels, knowing it was ready when a potato floated, with hand-me down recipes, and guesstimated measurements there was more reason for caution with the cure time. That stuff was often still caustic for some time. But with modern lye calculators and commercial lye we don't have to be quite as scared of "uncured" soaps, especially if it is superfatted.
    In general, I have found that most handmade soaps (both animal and plant based) are ready for use in 3 to 4 weeks. Though I do wait longer to package them, they will still shrink for some time.

  4. That's it. If armageddon happens, I'm crashing at your place. You have skills, woman! Skills!

  5. Cheers, Handcrafter :-) Oh, and ash-barrel lye is on my to-do list.

    Hey Demandra :-) If Armageddon happens, I'm thinking soap may not be at the top of my list of priorities!


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