In this post, I am going to share how to scale formulations. Understanding formulations and how to scale formulations is super important.
The first step is always to write down and make observations of what you are doing. So preplanning and organizing will help you have a great formulation session. We do this by writing our formulation and method.
One of the first steps in making your formulations more professional is measuring them by weight and not volume.
Volume is less accurate than mass. There are many reasons why you should use mass instead of volume. I will not go into all the reasons here but know that it is essential. By reading this post, I know, that you know that it's is important.
Parts of a Formulation:
I generally split my formulations into many parts. The first part is getting the general information, name of the formula, Batch size, Date made, who made it, etc. The next part is your table. I split this up into four parts. As a side note, I will have more when formulating a brand. Four columns are fine for people who are just making it for themselves. The parts for these columns are the phase, ingredient, percentage, and batch size or the grams. The phases can be tricky, so we will not focus on that. The phases are related to the method. We are going that all ingredients are phase A in these formulas for this post. Also, in the practice formulas, I will be listing the ingredients. Of course, this is also another topic of how to choose ingredients. And while we are on this train, the method is a whole other topic. The method is very important. We cannot treat every formulate the same way. To add, even ingredients that the same category; such as gelling agent, require different methods. The same ingredient from different suppliers can be like this way too. My advice is to see what the supplier says and look at their example formulations. That will at least be a starting point.
How do I know the percentage?
You want to look at the supplier's recommended usage rate. It may also be good to look at the supplier's formulation. There are guidelines. For sYou should always follow what the supplier recommends for some ingredients such as preservatives, antioxidants, and actives
Some parameters to think about:
You need to know that we are formulating by percent weight for the weight (%w/w). A refresher percentage means per 100. So if we have 100 percent, we have 100 grams. Another way to think about it is let’s say you have 50% water in your formula and you want to make 100g. You need 50 grams of water. This makes sense because if we have 50g of water and there is only one other ingredient, that would be 50g. 50g + 50g = 100g. Whatever the batch size is y,our formulation should add to that. So in our last example, it should add up to 100g. If we had a 5g batch, it should add up to 5g. The same goes for percentages but the percentage should always add up to 100%. If it does not, you cannot get the same same formulation.
Approaches to scaling formulas:
I want to give you a couple of ways of actually scaling formulas. Some may help you understand the concept better. When people read that there is math involved, I know they tend to freeze up. As long as your formulation adds to 100% and your calculated grams matches with the grams you wanted, you are fine.
As you add each ingredient subtract from 100. The formula I will show you below
This is the formulation we are going to be scaling. Say it is a toner formulation. From researching toners, we know that water is going to be most of the formulation. So we are going to make that the 100. You can say this 100%. With all formulations, you need to know the percentages for each ingredient. Once you start out formulating, this will be a complete guess for the most part. The example is simple enough to be okay as long as you follow supplier guides. I mention that because that is the next step. Subtract each percentage from 100%.
100% - 5% = 95%
95% - 1% = 94%
94% - 1.5%=92.5%
So the Distilled Water is 92% of our formulation.
To check your work, add all the percentages together and see if it adds up to 100%.
This is one method to find the percentage to add up to 100%.
The second method is similar but makes it easier on a calculator.
You are still subtracting from 100%, but you alter it so you can plug it all into calculator.
Note: The percentages for water, pH adjuster, preservative, and fragrance can be written as q.s. This means quantum sufficient or as much as needed. This gives flexibility in a formula to that if you want to use a preservative at 1%, you can. Suppliers do this mainly. The percentage of water can also be written as “to 100%”. This allows room for additional ingredients or to change the percentages. I wanted to point this out so that you did not get confused if you saw this in a supplier formulation.
Now let’s scale formulations!
There are multiple ways to scale a formulation.
I know this concept can be tricky, but you will have so much practice.
Let us use the previous example formulation.
So, this will be a bit of a review of algebra, but do not worry; it is simple.
Let's say that we want to make a 50g batch of this formulation.
If 100% = 100g, what do we have to multiply or divide to get 50g.
Here is the equation:
100g x =50g
X is our variable.
We can divide 50 by 100 to get x, our x is what we multiply our percentages to get our batch size, 50g. After doing that we get 1/2. So, we need to multiply all our percentage by 1/2. Alternatively you can divide all your formulation by 2, it would be the same thing.
Multiplying by 1/2
92 * 1/2 = 46g
5 * 1/2 = 2.5g
1 * 1/2 = 0.5g
1.5 * 1/2 = 0.75g
0.5 * 1/2 = 0.25g
Dividing by 2
92 /2 = 46g
5 /2 = 2.5g
1 /2 = 0.5g
1.5 /2 = 0.75g
0.5 /2 = 0.25g
To check our work:
It should add up to 50g which is our batch size.
Great! If you have been following along, you just scaled your first formulation.
For some more practice
Let's do some more formulation scaling.
Calculate the percentage of fractionated coconut oil, with one of the two method.
Then Scale to 50g batch
Calculate the percentage of Arrowroot powder of this formulation.
Scale to 50g.
So now that you are an expert at making a 50 gram batch, lets talk about others
What if you wanted to make a 500g batch. How would you do that?
All you have to do is multiply the percentages by 5.
What about a 10g batch?
Just divide your percentages by 10.
As a tip you can scale a formulation to 1g and then multiply it by by any number you want to get any batch size that you want. For some examples; 15g, 33g, 90g etc.
Formulation are to 100%.
You can multiply or divide by a variable to get the batch size that you want.
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You are at your own risk when making anything from this blog. I am not liable for any mishaps that may occur. I do my best to include everything in the procedure so, that accident are less likely occur!