Lye concentration determined by ...?

[WillZ]

Looking at various threads pertaining to LYE CONCENTRATION, I note that it's mostly a matter of what suits you. But that can't be right, surely.
In order to work out the best suited LC, wouldn't you have to know the exact amount of lye needed for a particular oil based on ????? within the oil ?

I just don't get it. (Which actually doesn't surprise me!!)

 

[amd]

I'm going to start a bit at the beginning for answering, you seem to have a few different questions going on in this post. Forgive me if I cover a basic amount of information that you already know.

Each oil has its own SAP value. SAP value is the number of milligrams of KOH (potassium hydroxide) or NaOH (sodium hydroxide) it takes to convert or "saponify" a fat into soap. KOH and NaOH may both be referred to as "lye", the difference between the two is if you want liquid soap (KOH) or solid soap (NaOH). When using an online soap calculator, you will tell it what type of lye you are using, what oils you are using, and what superfat (SF) you want to include in your soap. SF is a percentage of oils that you do not want converted into soap. (The reasoning for that is a whole 'nother story that I won't go into here, but I will tell you that most soapers use 3-8%, depending on oils and personal preference.)

The calculator will give you a lye quantity. That is completely based on your oils. For how much liquid to use - or lye concentration - that is dependent on you. You need an equal amount of liquid to completely dissolve lye. (e.g. if your lye is 2 ounces, you must have at least 2 ounces of liquid to completely dissolve it). I use water to lye ratio (water:lye) for my recipes because it is easy math for me if I need to adjust my recipe on the fly, but others will use lye concentration, or the less accurate 'water as % of oils'.

My personal preferences:
2:1 for a single color soap that only needs to be mixed and poured.
3:1 for swirling colors or designs
4:1 for really tricky FO's if I want any chance of a design
These are what work for me using my soap recipe and soap methods. Others will have different preferences based on their recipe and methods, so you may get a lot of differing advice. None of it is 'wrong', so take the time to play with your soapmaking to find what works for you. Start with small batches

 

[IrishLass]

Hi WillZ!

You are correct in that the lye amount is determined by the oils in your formula, but you're looking at it a little backwards- it's not the amount of lye that determines the concentration, but the amount of water mixed with the lye instead.


IrishLass

 

[shunt2011]

Lye concentration is just basically a water/liquid discount. Lye amount will pretty much always remain the same for a particular batch sized depending on your SF. Enter a recipe into soap calc then just adjust the lye concentration and see that the lye always stays the same only the water will change.

I see we all responded at the same time..... ha ha

 

[WillZ]

Thank you all!! I note that AMD for 'straight' soap uses twice as much water as lye. Why? When you only need the same amoun of water as the amount of lye,
When swirling then three times the amount of water, Does the amount of water slow down the sap process?
Can water be substituted for any liquid? Milk, coffee, flat beer etc.?

 

[jcandleattic]

When you only need the same amoun of water as the amount of lye,
When swirling then three times the amount of water, Does the amount of water slow down the sap process?

Using a 50% concentration is hard, things move very fast, as you are using very little water. You do not necessarily need 3 times the amount of water to do swirls. I use anywhere from 33% lye concentration to 40% and can swirl just fine depending on the oils used.

Technicially, no the amount of water does not slow down the sap process - however, whether it gels or not can affect the timing of saponification. More water tends to make soap gel easier, however, it also makes soap a bit stickier and harder to unmold faster.
I force gel with my low water concentration soaps by covering with towels and making sure the soap is somewhat cocooned and can get warm to increase the likelihood of gel. Some people force gel by HPing their soaps, or by CPOPing their soaps. It's all a personal preference.

 

[amd]

Thank you all!! I note that AMD for 'straight' soap uses twice as much water as lye. Why? When you only need the same amoun of water as the amount of lye,
When swirling then three times the amount of water, Does the amount of water slow down the sap process?

I do 2:1 for straight soap just to make sure that I absolutely do have enough water to dissolve the lye. I could easily use 1.5:1, but I like easy math, and I can do that one in my head rather painlessly.

For me and swirling, it comes down to my recipe and the method I use to soap. My recipe is 65% hard oils at room temp (or a bit chillier in the winter and someone closed my lab door) and fresh lye, so my batter will behave different than someone who heats oils to 80-90-100, whatever. I get the best results with 3:1, than compared to 2:1 (although I have never tried 2.5:1, again... easy math). It's all based on preference, I didn't mean to sound like you could ONLY do certain things at certain ratios. My intention was to say "this works for me and you may use it as a reference to start, but you should really play with your recipe to find what works for you".

 

[IrishLass]

Thank you all!! I note that AMD for 'straight' soap uses twice as much water as lye. Why? When you only need the same amoun of water as the amount of lye

What jcandleattic said- things move really fast with a 50% concentration. The steepest I ever do is a 40% concentration (for my 100% olive oil Castiles which take forever and a day to trace at lower concentrations). Since I like to swirl, soaping at 50% concentration is not an option for me.

When swirling then three times the amount of water

As jcandleattic said- not necessarily. Where my swirly batches are concerned, I find more often than not that much more depends on my formula, soaping temp and chosen FO rather than my water amount. I use a 33% (2:1) concentration for most of my batches and I have plenty of time to swirl in them. The fancy swirls that you see in my avatar picture were made using a 33% lye concentration with a well behaved FO (Tassie Lavender) in my 50% olive oil formula (soaped @ 111 degreesF). As I always like to say Formula, formula, formula!

Does the amount of water slow down the sap process?

Since I look at trace as an early stage of the sap process, I'm going to say technically yes, in contrast to jcandleattic's answer. lol Generally speaking, with all things being equal, the more water, the longer it normally takes for the batter to reach trace, and the less amount water, the quicker it normally takes to reach trace. Having said that though, there are extraneous factors that can come into play that can mess up the pace a bit.... or a lot... factors such as using a really ornery FO for example, or adding straight stearic acid, or applying extra heat etc...

Can water be substituted for any liquid? Milk, coffee, flat beer etc.?

Yes, any of those liquids can be subbed for water. I've used all of them and more, such as carrot juice and cucumber juice (not all in the same batch mind you, lol). You'll just need to take a few things into consideration when subbing in the other liquids. For example, the fat in milk will start to saponify once the lye is dissolved in it; coffee mixed with lye stinks to high heaven at first, but cures out nicely, etc....


IrishLass

 

[The Efficacious Gentleman]

Also many people use the "split method" they make a 50% lye solution with plain water, adding the rest of the liquid as their other milk or beer or whatever.

So if you need 150g of NaOH and would use 300g of water, you mix the NaOH with 150g of water, adding in 150g of other liquid when you combine it all together. This is particularly good for milks, as it avoids the lye clumping up in the milk

 

[WillZ]

Just to get this right: I add my flat Guiness or Camel Milk right after I have added my lye solution to the oils - right?

I really appreciate the help you all give. THANKS

 

[shunt2011]

Just to get this right: I add my flat Guiness or Camel Milk right after I have added my lye solution to the oils - right?

I really appreciate the help you all give. THANKS

I mix my milks into my oils before adding the lye solution. You can even add the lye directly to frozen beer or Camel Milk slowly not to burn it. I prefer mixing my lye with water and adding the milk/beer etc to my oils, stick blend well and then add the lye solution.

 

[WillZ]

Thanks Shunt, I'll go that route.