Water-Based PRODUCTS

What do I need to know?

RIP the Scale

​This is the last post in my DIY Cosmetics for Beginners series! I can't believe that it is ending!?!? It feels like I started it yesterday. Anyway, in this post we are going to be talking about water-based cosmetics. Most of this post is going to be a review from previous posts. This was meant to happen, as I wanted to give the beginners the skills and knowledge to follow along with the formulations that I create. I am going to include how do all the math for conversions and scaling up and down. Don't worry all you will need is a piece of paper and a pen or pencil. You may need to erase, as mistake do happen. So, time for review!

Water-based formulations can be some of the easiest formulations. It can be as simple as adding water-soluble ingredient into water and then adding a preservative and you are done. Simple right! On the other hand, it can be as complex as an emulsions. Which we will come in another series on the Diamond Level Blog. (Link)  So, water-based formulations can range in difficulty, is what I am try to get at, which is really true for anything in life. Because we are working with water we also have to take into consideration somethings. We need a preservative and we need to check and adjust the pH of your final product. This should not be new. If it is, you may want to look back in the series for additional information and the rational. I said earlier in this series (on the post about pH [Link]) that I was going to show you to make the stock solution. So this is going to be the post to do it.

How to create pH stock solutions.
To raise the pH:

• Create a 50% citric acid solution
  • To make a 50 gram sample: In separate containers measure out 25 grams of distilled water in a Heat-safe measuring cup and in another container measure out 25 grams of citric acid. After that, add the citric acid into the water in the glass cup. Don’t do it the other way around. This will need to be heated slightly until the citric acid is fully dissolved the citric acid. Once dissolved then, you are done
    • These solutions do not need a preservative as the pH is too low for any microbes to grow.

To Lower the pH:

• Create a 30% sodium hydroxide solution or alternatively, use undiluted TEA
  • To make a 50 gram sample: In separate containers, measure out 35 grams of distilled water into a heat-safe measuring cup and in a prep cup measure out 15 grams of sodium hydroxide aka Lye. After that, add the Lye into the water the glass cup. Don’t do it the other way around, we do not need an explosion! This will need to be heated to fully dissolve the lye. Once dissolved then, you are done! Note

Idea and some information was used from here. :)
Beginners Cosmetic Science workshops - Free trial

Typically, with adjusting pH, it will not need a drastic change. It can be as little as one drop or as much as ten drops. It all depends on how far off the pH strip or the pH meter tells you. Also, pH adjusting is the last step in your formulation. As some ingredients may alter the pH. So, it is best to leave it to the last step.
Strips Vs. a PH Meter
To be honest it really depends on your budget and what the type of formulations you are doing. For beginners, strips are fine. For more advanced formulators a pH meter would be better. Yes, the meter is more accurate but, you can still get away with. Personally I just use a $16 pH meter form amazon. I still have to get some more practice with it to see if I recommend it or not. It is another option to think about. The really nice ones are around $80 on ebay. So, yea.        

Now for the math!
The math that we will be doing is very simple! No tangents, vertical asymptotes, or Pythagorean theorem! :)

I am going to go step-by-step on how to write and scale formulations.
Here are the fundamental facts:

• Formulations start as percents. 
• To find the percentages, you need to look at what the supplier suggests as the percentage. On the diamond level blog, I have a section that you can easily find all this information. 
• We use percentages so that we can scale up or down formulations.
• 100% = 100 grams so, it is a 1 to 1 conversion.
• Our end goal is to have a formulation that adds up to %100 and nothing more and nothing less.
• The general rule is oil-based formulations; your liquid oil portion will be the most. For water-based formulations, the majority is water; this is also somewhat true for emulsions. However, it depends on the type you are making. For the most part, we create oil in water emulsions, so the water will be the most substantial part.   

So let's say we are going to make a toner spray.
Toners are mainly water.
So we are going to start with 100% water. I have simplified gram to g.

100%/100g Distilled water

Everything after this, we are going to be subtracting from the 100g and 100%. We can deduct from both because we are working at a 1 to 1 conversion, so there is not additional math. We adjust the grams to how many we want after. For the first addition, I want to have half of the water be rose water. To do this, we take half of 100% to get 50%.

100%-50%=50%

 So, it would change to:

50%/50g Distilled water
50%/50g Rosewater

For the next addition, we will add 5% glycerin. So, I subtract five from 50. We are going to be taking it out of the distilled water so that we can keep 50% to rose water.

50-5=45

Now the percent of water changes to also include Glycerin. So the recipe changes.

45%/45g Distilled water
50%/50g Rosewater
5%/5g Glycerin

The next two ingredients I want to add are a preservative used at 0.5% and Green tea extract at 1%. Again we are going to be subtracting from the distilled water.

45-0.5=44.5

44.5-1=43.5

So the recipe changes to:

43.5%/43.5g Distilled water
50%/50g Rosewater
5%/5g Glycerin
1%/1g Green tea extract
0.5%/0.5g Preservative (Liquid Germall Plus as an example)

And then you are done with the math! You also have the recipe to make a 100-gram batch.
Let's say you only wanted to make a 50-gram batch or even a 25 gram batch to as big as 200 grams. Well, that is easy. For a 50 gram batch, divide the whole formulation by 2. 
that would look like this
50 grams
43.5%/21.75g Distilled water (43.5 [from original formula] /2= 21.75)
50%/25g Rosewater (50/2=25)
5%/2.5g Glycerin
1%/0.5g Green tea extract
0.5%/0.25g Preservative 

For 25 grams, divide the whole formulation by 4. How? 25* n = 100, Divide both sides by 25 to cancel the 25 and to get n by itself. Once you are done with that, you are left with n=4. So, if your formula = 25 grams, we will need to divide 100 by 4.

25 grams
43.5%/10.89g Distilled water (43.5 [from original formula] /4= 10.875 round to 10.89)
50%/12.5g Rosewater (50/4=
5%/ 1.25g Glycerin
1%/0.25g Green tea extract
0.5%/0.13g Preservative (Liquid Germall Plus as an example)

 To scale up, it is a simple multiplication problem. To make a double batch multiply the percentages by 2 to find the 200 gram batch.

200-gram batch
43.5%/87g Distilled water
50%/100g Rosewater
5%/10g Glycerin
1%/2g Green tea extract
0.5%/1g Preservative

And you are done! I hope this was extremely helpful for everyone! Let me know what you think! 

Done and want more? Find post about emulsions, solublizers, and surfactants the second part to this series on the Diamond Level Blog. (Link) I also have a series where I walk you step-by-step on how to make different products like face washes, toners, masks, face lotions, and serums. 

Previous Post in Series