Hot or cold process soap? Which is the best method and is one easier than the other? I am very much a fan of both - is that allowed? If I had to sway one way it would probably be cold process now, mainly because it has many more possibilities, is flexible and making larger batches is easier but there is a little more that can go wrong. If you asked me the same question a few years ago however I would have said hot process as that is the method I built my business using and at the time I found it more forgiving.
If you are unsure what the difference is, cold process is the age old traditional method, no external heat is used during the process other than to melt the oils. Curing time for your soap is 4 to 6 weeks.
Hot process soap making involves 'cooking' your soap which speeds the saponification process up considerably however a cure is still needed albeit I think you can get away with using a it a little sooner.
Cold Process - The Good Bits!
1 Minimal equipment needed, generally just kitchen jugs , a digital thermometer and a cheap household blender plus your chosen ingredients.
2 The option to make multi coloured soap easily
3 A huge variety of techniques are available to produce beautiful patterns and swirls ye
4 The initial making of your soap is relatively quick, less than hour
5 The finished soap is smooth and attractive to look at, a more polished product.
Cold Process - The Bad Bits!
1 There is a 4 to 6 week delay before you can use your finished soap
2 The clearing up is harder, you either deal with caustic soap dishes on the day or leave them somewhere safe until the following day when the soap batter will have turned to soap.
3 Not all scents, particularly essential oils, do well in cold process soap. The initial, extreme alkaline conditions can cause them to morph into something else or disappear.
4 There are some issues such as soda ash appearing on the top of your soap which only occurs in cold as opposed to hot process soaps
5 You need to plan a little further ahead if you want to make soap for seasonal events such as Christmas.
Hot Process - The Good Bits
1 Speed - you can use your soap a little faster although it will still benefit from as long a cure as you can give it.
2 Easy clean up. Just soak your slow cooker and spoons etc in hot water to dissolve soap away
3 Essential oils remain truer in scent as you add them after the cook and they do not have to survive the saponification process.
4 A little less planning for special occasions/events may be needed.
5 Less space needed to store soap while you wait for it to cure. I don't feel it needs quite the same amount of space and air flow as cold process - it seems a little more hardy in that respect.
6 You can choose your superfat! ie You can choose a really luxurious butter or oil and add it in after your soap is cooked and it will not be turned in to soap but remain free floating which will in turn be extra moisturising for your skin.
Hot Process - The Bad Bits
1 It is not as pretty! It can look a little rough around the edges - aka rustic.
2 It is much harder to do lovely swirls and different colours - it is not impossible but you need to be very experienced, use a slightly different method which is harder to accomplish and add extra ingredients to keep your soap batter fluid - and to be honest it still does not swirl as well.
3 You cannot make such large batches although unless you have a soap business this is not an issue .
4 It is harder to use additives such as milk or fresh vegetable juices as they may burn and go brown.
I genuinely cannot think of any other negatives of hot process and I have an extra 'pro' which does really confirm my preference for hot process soap making.
I teach both hot and cold process soap making. If you would like to find out more about my soap making workshops then take a look here or if you prefer to learn in the comfort of your own home but with online support form me then check out my eBook here or online soap making video course here. I am also now running online live Zoom courses which can be booked through the website when dates are available.