Beginner soapmaking without a digital scale?

Does anyone successfully make lye soap without a digital scale?

I have an analogue one that measures in 25g or 1oz increments, but can’t get any more accurate than that. Getting a digital scale is not an option.

A lady at our homeschooling group who makes soap suggested using too little lye rather than too much, so that I just end up with some extra fat that wasn’t saponified rather than my soap having too much lye. Has anyone here tried this approach?

I’m also wondering what soap is like made from 100% tallow? Is mixing in some other oils going to make it a lot better? What oils would you add, and what percentage? I’m aiming for a nice general hand washing bar of soap that will lather well.

I found the following recipe in an old issue of Grass Roots magazine, it’s designed for using up a whole jar of lye at once, and I am wondering how it will work if I replace the vegetable oils with beef tallow and use frozen goat milk for some of the liquid.

3kg total fats (original recipe used a mix of olive, coconut, palm, and macadamia, I want to use 100% tallow)
2 litres water (How much of this can I replace with goats milk?)
500g lye

What are your thoughts?

Absolutely no experience with soap making, with some simple maths, it's possible to convert the recipe to "Parts".  Use the smallest amount (the lye) for the divisor to equal 1 part,  so the recipe given above would be:-
3 kg fats   would be 3kg/500g  = 6 parts
2 litres water(2kg)  2kg/500g  = 4 parts
500g lye (your smallest qty)   = 1 part
Then it's possible to use any container to measure out the ingredients - cup, tablespoons, vegemite jar etc.
The usual lye is sodium hydroxide or potassium hydroxide crystals or powder and will burn skin on contact - so safety glasses, a face mask and rubber gloves come highly recommended.   As a substitute, lye made from wood ash is an historical  ingredient - that makes a potassium hydroxide solution and will need some more research and experimentation, but far safer!    Over to you - let us know how you go.

Kate,

For my ceramics shop I use a vintage Ohaus scale with 0.1 g precision and 1.6 kg max weight.
I like to measure specific gravity of materials that I use. After that I can use measuring spoons and cups.

From what I can figure out, cold process needs extremely percise weights.  Hot process was more common in rural homes pre electricity, as it can be modified as you cook it. It can even be done with approximate volumes.  It can also be done with impercise fats like used cooking oil that has been cleaned.  It also has different dangers than modern cold press that is so popular now.

As for how any of that works, I haven't had the courage to try it.  But memory says the words to start with are hot processed soap.

Jill Dyer wrote:Absolutely no experience with soap making, with some simple maths, it's possible to convert the recipe to "Parts".  Use the smallest amount (the lye) for the divisor to equal 1 part,  so the recipe given above would be:-
3 kg fats   would be 3kg/500g  = 6 parts
2 litres water(2kg)  2kg/500g  = 4 parts
500g lye (your smallest qty)   = 1 part
Then it's possible to use any container to measure out the ingredients - cup, tablespoons, vegemite jar etc.
The usual lye is sodium hydroxide or potassium hydroxide crystals or powder and will burn skin on contact - so safety glasses, a face mask and rubber gloves come highly recommended.   As a substitute, lye made from wood ash is an historical  ingredient - that makes a potassium hydroxide solution and will need some more research and experimentation, but far safer!    Over to you - let us know how you go.

Luckily the lye comes in 500g packs, so there's no need to measure that for the recipe.

I don't think this weight = volume approach would work with baking, because the dry ingredients are going to weigh less than the liquid ingredients, for example, 1 cup of water weighs 240g, 1 cup of flour, around 128g, so for soapmaking, if the cup weight of lye is similar to flour, measuring by parts in volume is going to result in nearly half the amount of lye that's needed.

r ranson wrote:From what I can figure out, cold process needs extremely percise weights.  Hot process was more common in rural homes pre electricity, as it can be modified as you cook it. It can even be done with approximate volumes.  It can also be done with impercise fats like used cooking oil that has been cleaned.  It also has different dangers than modern cold press that is so popular now.

As for how any of that works, I haven't had the courage to try it.  But memory says the words to start with are hot processed soap.

I've never heard of hot process soap before, so this gives me something new to look into, thanks for sharing. I've only heard of the kind of soap where the fat is there, then lye is added to water, then the water/lye mix gets added to the fat, so I assume this is cold process because it doesn't get heated.

I make hot process soap, almost always, but I've also done cold process. From everything I've read, watched, and my own experience (I'm no pro, I just make it for our own hygiene use, household cleaners, and gifts - no selling), it is all done by weight, exclusively. That said, there were no digital scales, when my grandma made her soap. Then again, her soaps, from my mom's memory, were a bit... 'catch as catch can'. In other words, they were extremely inconsistent.

I would love to be able to help more, but so far, I've not tried soap making with my gram weights... yet.

I make cold process soap, and for starters the fat used determines how much lye you need. You cannot use the same amounts lye and fat for whatever fat or mix of you have. There are calculators for such online :
http://soapcalc.net/calc/SoapCalcWP.asp

Otherwise, yes use more fat then the lye needs i.e. oversaturation, 3-5% is normal for some mosturizing and the safety that all the lye has found some fat to join with. You can use fairly limited amount of water (less shrinkage of soap during curing process), but fat and lye are the chemical reaction here, the water just helps things come together.

There are people that make the lye even, (running water through woodash), but that is a hit or mis thing strength wise and if you want bars of soap that need to cure, are way milder on your hands and can be stored you'll need to add salt to the mix. The lye you can now buy for soap making is sodiumhydroxide (sodium being the salt). So total number of ingredients in barsoap is 4 (water, lye, salt, fat).

I use just oliveoil because i can easily get it and i started making soap to replace the alleppo soap that while good was both expensive and awkward to handle. Now with individual molds the soaps are both pretty and invite handling and thus use (and that is what they are for).

While i would like having volume measurements for soap, i don't want to risk it, i make it for myself and a few family members like a few small batches every 2 years or so. Experimenting is fun, but i cannot test for safety well enough other then just use it to want to mess with alternative ways of portioning the ingredients. Adding some coffee grounds is a good addition for getting hands clean after gardening and such and it looks like a tsp of honey is good also, but other amounts go by weight to the gram.

Kate Downham wrote:

r ranson wrote:From what I can figure out, cold process needs extremely percise weights.  Hot process was more common in rural homes pre electricity, as it can be modified as you cook it. It can even be done with approximate volumes.  It can also be done with impercise fats like used cooking oil that has been cleaned.  It also has different dangers than modern cold press that is so popular now.

As for how any of that works, I haven't had the courage to try it.  But memory says the words to start with are hot processed soap.

I've never heard of hot process soap before, so this gives me something new to look into, thanks for sharing. I've only heard of the kind of soap where the fat is there, then lye is added to water, then the water/lye mix gets added to the fat, so I assume this is cold process because it doesn't get heated.

My limited understanding is that cold process soap needs curing time as the lye continues to (big word, starts with s, can't spell it well enough but basically means soapify) for days or weeks before we can use it.  That's why measuring by weight and fancy tables of how each oil sopifies are so important.  The lye can be leftover and hurt skin if not measured right.  We won't know until it is too late to fix.

Hot process soap there are ways to tell if it's done while it cooks, but still likes a curing time.  Because of this, knowing which fat and soapify tables and whatnot, is less important.  It would be the way done in old household manuals pre 1880s which generally uses volume or larger weights like pounds depending on the book.  Some 20th century periods also return to this style of soap making. But note, many of the authors of the books weren't the people cooking (especially in the 1850s), so it helps to know the science when evaluating the old soap recipes.  

There are also some good ones from the government manuals from the two world wars when soap (and all fats) was in scarce supply.  UK ones were most helpful if memory serves. The usa had some soap making in one of the ww1 manuals (fat was still used in some animation and weapons making). The commonwealth countries mostly didn't have dangerous fat shortages for civilians so the rationing guidelines don't seem to include soap.  But other books from that time sometimes do.  I don't have access to my books to look up the details right now and am dredging this from old memories from before I found a soap that doesn't hurt my skin.

My research was over 15 years ago and at that time, the internet was exclusively cold process soap and shunned hot processed as something best left in the past.  Same with books written post 1950.  It was very difficult to find 21century resources on hot process back then.  Thus my need to go to historical references.

In one or the historical reenactments, Ruth Goodman made hot processed soap using wood ash lye.  Possibly the tudor or medieval series.  This was hot processed as it's difficult to judge how strong the lye from leached woodash is.

Could you get a small digital scale just for the lye?  They are cheap when they are small, it’s getting one that measures multiple kilos accurately that gets expensive.

Another option is to make a lye solution and test it with pH strips, then you can convert to ml. But you will lose the heat of the lye and basically need to do hot process. I know I have seen this in old wood ash recipes, testing the lye strength with red cabbage.  You’ll have to google the specifics.

Modern cold process works with exact weights because the oils are well known and researched. You can’t switch oils ounce for ounce because they behave differently. A recipe that calls for a kilo of tallow might need 1.5 of coconut oil to use up the same amount of lye (numbers made up). I read someone found fake olive oil because it behaved so differently in the soap recipe. There are online soap calculators that will tell you how much lye you need for whatever mix of oils you use.

I've been about to reply to this thread several times but refrained since I don't have experience with tallow, but I figure this might be helpful.
My mother in law taught me to make soap with a volume measurement. It is amazing for cleaning, definitely way heavy on the lye (fails the zap test, has some white powderish on the outside, but doesn't burn skin. it is aged for a long time, at least a month, which may be why).

She uses 5 L of whatever USED cooking oil (lard, soy, whatever, the dirtier the better. Filter out the nasties first)
1L water
1L liquid lye (which here is 50% water, so your 500g)
That's it. Cold process, put in molds, age, cut and use.

I ran the soap calc on 5L of soybean oil and it told me I needed 136 grams of sodium lye, but it didn't have an option for liquid lye, so not sure. I don't know where she got this recipe from but she's been doing it for decades, and every time I try it it works just fine. Keep in mind my mother in law is not a literate person, and she uses this soap for heavy duty stuff, so the lye overkill may be helpful as well as easy for her to remember since she's not writing down recipes or googling things.

I'm a beginner too, but have made both cold and hot process soaps.  I don't have a digital scale.  I use a soap calculator and play around with the exact measurement for the amount of lye I have and can measure with my analogue scale.  Mine is an old fashioned baking scale with oz weights, the smallest being 0.5 oz.  So I make sure my lye measurement in my soap calculator recipe is at whole or half numbers.

I also use mainly tallow but it makes a hard soap that doesn't lather much.  Not many bubbles.  For hand/body soap, I replace about a quarter of the tallow with coconut oil (coconut is bubbly but drying, tallow is moisturising).  The 100% tallow soap I like for laundry;  I make it a 0% superfat recipe for this, and hot process in my slow cooker.

I have made soap a few times using ash lye and random left-over bits of fat. No scales, no volume measuring, not even a recipe. Not much point when you'd have to guess at the concentration of the lye. I suppose you could boil the lye down to potash and weigh that, but it seems like a bother. So I just tested the soap frequently as it was, uh, cooking, by taking a pinch of it and washing my finger tips with it. If the fingers end up feeling fatty, add lye. If they keep feeling lye-slippery for a long time and feel dry afterwards, add fat. This is safe when using ash lye (potassium carbonate) but probably a bad idea if you use sodium hydroxide. A friend of mine said she had talked to (or just heard of?) an old lady who used to test this by tasting the soap while cooking! That feels a bit too hardcore for me though, I'd like to keep my tongue intact...

And the results? Well, like Carla mentioned, it's a surprise each time. One batch, that I made with a friend, turned out just great. A couple others were okay, but generally with a touch too much fat. One batch I had to discard, since it refused to set (don't know if that's the correct term) but stayed a very liquid foam, despite much of the fat being tallow. I kept stirring it for bloody ages, but it just refused, and eventually it got burnt in the bottom. Arrgh... Still have no clue why.

In conclusion, soap making without weighing and measuring is definitely possible, and can turn out wonderful. If you love surprises, it's great. If you value a consistent end product, not so much.

R Scott wrote:Another option is to make a lye solution and test it with pH strips, then you can convert to ml. But you will lose the heat of the lye and basically need to do hot process. I know I have seen this in old wood ash recipes, testing the lye strength with red cabbage.  You’ll have to google the specifics.

For cold processing the ingredients need to be the same temperature i.e. if everything is liquid at roomtemperature you are fine.
I don't heat my olive oil (another reason it is all i use for making soap), just make the lye water mix the evening before and let it calm/cool overnight. Weigh oil next morning, add lye, mix with soap designated blender and poor into molds. Doesn't work with hard fats, but i don't use those (heating fats makes them temperamental and lye itself has enough of that for me).

Lard and tallow don't make for a very good lather, even though they clean well. For a better lather, add some castor oil, olive oil, or coconut oil. A little sugar or honey can also help immensely, with the lather - just make it the last thing you add, to keep the lye from scorching it badly. The sugar & honey will darken your soap, anyway - but less so, if it's added after the lye has mostly cooled. Also, if you use honey, make sure it's not begun to crystallize, at all. I used honey once, that had apparently just begun to crystallize, and it broke the whole batch. It was absolutely useless. Couldn't go into the compost, even.  I took it to my local soap making guru (she really does have a thriving soap business), and she's the one who told me what had gone wrong - she also learned it from experience - and then a mentor.

Thank you all for the helpful responses. It’s been especially good to hear about personal experience with hot process, wood ash lye, and other stuff that’s a bit off the beaten track of modern soapmaking. It’s important to keep these skills alive.