Thursday, March 5, 2015

Question: Determining how much to use when working with powders

From this post, Making a water-in-silicone serum, Nanette asks: How do you determine the correct percentages of powdered ingredients? 2% of powder A could weigh significantly more than 2% of Powder B.

These kind of conundrums are the reason we weigh all our ingredients intead of using teaspoons or tablespoons. How much allantoin are we adding if we use 1 teaspoon or 5 ml? How much if we use 10 ml? And so on. It's so much easier to use 0.5 grams in 100 grams of product and know that we are using 0.5% allantoin in that product.

How to convert any recipe from percentages to grams? Convert the % sign to the word "grams" and you will have a 100 gram batch. If you want 500 grams, convert the % sign to the word "grams" and multiply by 5. And so on.

Always always always weigh your ingredients. Don't do the "5 grams of this, 1 ml of that" recipes as they are hard to scale up when you want to make bigger batches. As well, how do you know how much of something you've used in percentages if you've added 5 ml of something to a 100 gram batch?

Oils have a specific density of 0.90 grams per ml. So adding 5 ml to a 100 gram batch of product means you've added 4.5%. Glycerin has a specific density of 1.263 grams per ml, so added 5 ml to a batch, means you've actually added 6.315% to your product.

So the short answer to your question, Nanette, is that 2% of powder A and 2% of powder B will always be the same if you are using weighted measurements! (You'll have 2 grams of A and 2 grams of B!)

Related posts:
Why we weigh ingredients! 
How to convert recipes from percentages to weights! 
How do I figure out the volume of a recipe? Specific gravity

12 comments:

Lisa Reidzans Schmock said...

I have been weighing most everything by grams, but some things, I ended up using a pipette and going by ml, I take it thats wrong ;) Im getting a new scale on Saturday that will weigh by .1 grams but I still get confused. Using LGP has been a big one because its so thick, but going forward I will weigh everything. Although, I have some aloe vera gel in a gel form, was trying to make an eye gel from the facial products book, and 40% or whatever the recipe called for in weight was a huge amount, I only wanted to make 60grams total and I think I ended up with tripe that. What did I do wrong?

Thanks!

Lisa

Lisa Reidzans Schmock said...

Sorry! I meant to ask. I have cetyl alcohol NF in bead form, or well any of the stuff I have in bead or flake form, that also gets weighed on the scale too right? Sorry, I think Im just asking the same questions ;)

Thanks!

Lisa

B. said...

Lisa,

Liquid, beads, flakes, powders, everything has a weight, hence can be weighed. What comes to getting too much of something, you can always divide the numbers by 2 or 3. Let's say you didn't want 100 grams of eye cream - you would take the 40%/40g of aloe Vera gel and divide it by 2, hence getting 20 grams. Do that to all the ingredients and you end up with 50 grams of product while still keeping the right ratios. Hope this helps,
B.

Nanette said...

Thank you, Susan. I do weigh everything. After all, I follow your blog! I was making a facial moisturizer with 2% niacinamide in a 100 gram batch. That two grams of naicinamide seemed huge. I thought I had wrapped my head around powders but I began second guessing myself and was sure I was overloading the niacinamide. I don't know why since I don't question the measurements in weight of flakes, pellets, liquids, butters, or even allantoin. I will proceed as usual and I thank you for putting my mind at ease.

Lisa Reidzans Schmock said...

So B, the original recipe called for 80% Gel, and 5% of 4 other ingredients. I was making a 60 gram batch, I just realized I can't add, as I used 40 grams of gel and 20 grams of the 4 other ingredients to reach 60 grams. Like I said it came out with way too much gel. Man I just don't get it. Maybe I'm making too big of a batch. If I do a 20 gram batch, that will be 16 grams of gel, and 1% of the other 4 ingredients. I think I can live with that ;) I should have read Susans instructions more carefully, she said not to make too big of a batch! Thanks for your help!

Lisa Reidzans Schmock said...

Nanette, I have the same issue with powders and light weight flakes, pellets etc. It seems like 25% (so lets say 25 grams of a 100 gram batch) of like LipidThix which is a powder, is a huge amount. I'm gonna have to play around this weekend and see what I make ;)

Lisa

Nanette said...

Lisa,

Will you post any results you find noteworthy?
How do you like LipidThix? I haven't tried that yet.

Lisa Reidzans Schmock said...

Nanette,

Haven't tried it yet ;) Bought it a few weeks back not realizing that Susan did some posts on it. I'm going to be making Sweet Almond Butter, Hazelnut Butter, and Rice Bran Butter so far this weekend. I will post my results!

B. said...

Lisa,

If the original recipe called for 80% gel and 5% of each of four different ingredients, then to make a 50 gram batch you would use 40g of gel and 2,5% of all the other ingredients. You have to divide all of the numbers, not just one. By doing the recipe 40-5-5-5-5, you ended up using 67% gel, and 8% of the other ingredients, even though the original recipe called for 80-5-5-5-5.

B.

B. said...

Sorry, I meant that to make a 50 gram batch you would use 40g gel and 2.5g other ingredients.
B.

Susan Barclay-Nichols said...

Hi everyone! I have written a post about recipes and calcuations as today's Weekend Wonderings.

And here are a few links to Lipidthix posts! Let us know about your experiments!
Why'd I buy that again? Lipidthix
Lipidthix: Making a butter
Lipidthix: Using 25% to make a butter

Nanette said...

Oh great, Susan, now I have to try this ingredient! But, wait, what about that lamellar liquid crystal emulsion system that looks so cool, or the system with ceramides, or buying some sea kelp, or some N-acetyl glucosamine to go with the niacinamide, or... Sheesh, I am hopelessly addicted to this.

Thanks for posting the links. I'm always impressed with your follow up and how you look after us.