Having become familiar with the cold process of soapmaking – I can’t claim to have mastered it yet, not by a long shot – I decided to have a go at the hot process.
The main advantage to hot process soap is that you don’t have to leave it to cure for 4-6 weeks before you can use it. (You can technically use cold process soap without curing it but it will be very soft and not last long at all, so it’s general practice to let it cure. Soaps with a high or total olive oil content should ideally be left to cure for 6-12 months!) Hot process soap is ready to go as soon as it’s out of the mould. It’s ideal, therefore, for impatient people like me.
In a nutshell, ‘hot process’ means making soap in a crockpot, or slow cooker. (But not, of course, in the one that belongs to your daughter and which is currently in your safe-keeping while she’s working and studying abroad. And which, naturally, you won’t also borrow to make rose-hip oil in.) You melt all your oils, both hard and soft, in it, add the lye mixture, wuzz it with a hand blender until it becomes thick (this is called the trace stage), and then leave it to cook for about an hour.
All two of my mixtures so far have behaved themselves, but apparently the soap can occasionally try to climb out of the crockpot during this cooking stage so it’s as well to keep an eye on proceedings. Once the soap has gelled, i.e. become a sort of lump of translucent porridge, it’s time to wuzz it again and then splodge it into moulds. It’s very puddingy and a bit unwieldy by now, so the resulting soap has a decidedly rustic look to it. Ideally you should make this soap in one large mould so you can trim the rough top (which will become the bottom when it’s turned out) so it’s neater. I only have small moulds, but I can tidy them up a bit although they’ll remain markedly uneven.
I’m not entirely sure if I think the soap looks attractive or not. My first batch looked terrible, but that’s because I forgot to stir it after it got to the gel phase. I just forced resisting lumps of soap porridge into my moulds. Fortunately I remembered this crucial step with the second batch, and the result is a little less unnerving. I’ve since come across another technique to try which, by holding back some of the water that goes into the soap and only adding it after the gel phase, results in a more fluid mix to get into moulds. I’ll try that next, in the optimistic expectation that it will produce better-looking soap.
You’re possibly imagining that my poor family is knee-deep in soap by now. Whilst stocks are undeniably building up, we’re not yet overwhelmed as I’m only making small batches at a time. The traditional size of a batch is 3 lbs: I generally go for a quarter of that, a third at tops. I also alternate between shampoo bars and soap for not just variety but also all-round cleanliness.
I’m still not quite there with scenting the soaps, which you’d think would be the easy bit compared with the trickier elements such as correct saponification, getting your mixture to trace and managing the gelling phase. I probably don’t use enough essential oils, but the recipes tend to call for rather eye-watering amounts, frequently several ounces. One of those small essential oil bottles contains a mere third of an ounce, so you could burn through them, and money, rather quickly. You can get away with using less if you add the fragrance at the right point: at trace with cold process soap, and just before moulding with hot process soap. If you add your essential oil too soon the scent gets lost in the cooking. Essential oils can also add colour to your soap – some are surprisingly murky in appearance – and also affect the rate at which the soap thickens. More to them than meets the eye. I’m already tending towards the stronger, and cheaper, fragrance oils, but maybe as my expertise, and I use the word loosely, increases I’ll get a better handle on the essentials of handling essential oils.
Time will tell!