Tuesday, January 27, 2015

How do I modify a recipe when I add or remove an ingredient?

Let's take a look today at altering recipes as there have been a lot of questions about this lately. (Original post can be found here...)

Let's say I have this recipe from this post:

SWIFT'S BASIC HAND LOTION FORMULA
69.5% water
15% oil
5% butter
3% cetyl alcohol or stearic acid
6% Polawax
1% fragrance oil
0.5% liquid Germall Plus

Please use the general lotion making instructions for this recipe.

Let's say I wanted to add a few things to the recipe. I think it might be quite nice to have some glycerin, allantoin, hydrolyzed protein, and panthenol in the mix. How would I add them?

How do I know when to add an ingredient? If they are water soluble and can withstand heat, they would go into the heated water phase. If they are oil soluble and can withstand heat, they would go into the heated oil phase. If they are oil or water soluble and can't withstand heat, they would go into the cool down phase.

Glycerin, allantoin, and hydrolyzed protein are water soluble and can withstand heat, so they go into the heated water phase. Panthenol is water soluble and can't withstand heat, so it goes into the cool down phase.

How do I know how much to add to the mix? Check the suggested usage rate, which can be found at your supplier's website, and trial and error in your workshop. I could add tons of glycerin, but I think I'll go with 3% because I have found that anything over that tends to feel a bit sticky to me. I know that 0.5% allantoin is a good amount because I've used 1% and thought it was a bit gritty. I like to add hydrolyzed proteins at 2% (generally) because that seems to be a nice level that offers some film forming without potential stickiness. And I've read that panthenol is effective at 2%. I have found it can get a bit sticky above that level, so I'll keep it at 2%.

How do I add these ingredients? I would remove the amount of the ingredient from the water portion. So if I'm adding 3% glycerin + 0.5% allantoin + 2% hydrolyzed protein + 2% panthenol = 7.5% new ingredients. I will remove 7.5% from the water amount, leaving me with 61.5% water in this product.

HEATED WATER PHASE
62% water
3% glycerin
2% hydrolyzed protein
0.5% allantoin

HEATED OIL PHASE
15% oil
5% butter
3% cetyl alcohol or stearic acid
6% Polawax

COOL DOWN PHASE
2% panthenol
1% fragrance oil
0.5% liquid Germall plus

If you wanted to remove or add something that is oil soluble, it gets more complicated. Because oil soluble things need to be emulsified, an increase or decrease in an oil soluble ingredients means an increase or decrease in the emulsifier. In this recipe, let's say you wanted to remove the butter. This means you are losing 5% oil in the recipe. You don't need as much emulsifier, so you could reduce the Polawax by 1.25%. You would then add 6.25% to the water phase.

All recipes should add up to 100% for ease of reading and formulating. So if you remove something, you have to make it up somewhere. We make it up in the water amount. Yes, this will change the viscosity, but that's the nature of changing a recipe!

Why did I reduce the Polawax by 1.25%? Because we use Polawax at 25% of the oil phase. Add up all the oil soluble ingredients and multiply by 0.25 to determine how much Polawax we would use. If you are using another emulsifier, you would have to do different calculations.

HEATED WATER PHASE
68.5% water
3% glycerin
2% hydrolyzed protein
0.5% allantoin

HEATED OIL PHASE
15% oil
3% cetyl alcohol or stearic acid
4.75% Polawax

COOL DOWN PHASE
2% panthenol
1% fragrance oil
0.5% liquid Germall plus

I hope this exercise has given you an idea of how to modify your recipes. Please check out the related posts to which I link below if you want more information!

Related posts:
Back to the very basics: Defining our terms for lotions
How do I modify a recipe when I add or subtract an ingredient?
Learning how to read and convert a recipe
Newbie Tuesday: Let's make a lotion!
Making your first lotion (PDF)

8 comments:

K.Line said...

Hi There: I live in Canada and I'm new to the lotion making process. As yet, while I access to most component products (like polawax), I can't seem to find stearic acid or cetyl alcohol. Shipping is very expensive here, even within Canada, so I'm wondering if I can sub out those products with something else that would be easier to find locally. I sense they're added to add thickness to the mixture (but are distinct from the emulsifier in which they're also found), but I'm not sure - hence the question.

Thanks so much for feedback and, if you've already answered this in another post, apologies - I'm new to your blog...

Susan Barclay-Nichols said...

Hi K Line. I'm in Canada, and those ingredients are super easy to get an really inexpensive compared to our butters, which would be my suggested replacement. Check out the post in the FAQ for suppliers in Canada or look to the right hand side for Canadian suppliers like Voyageur.

Susanna Originals said...

Hi Susan,
I was snowbound yesterday so it was a good chance to experiment with your basic moisturizer recipe. Here's what I used:
Water Phase:
15% aloe
10% lavender hydrosol
44% distilled water
3% glycerine
Oil Phase:
10% jojoba carrier oil
10% aloe butter
5% polawax
2% cetyl alcohol
Cool Down:
0.5% germail plus
1% blend of lavender and patchouli EO
Pretty close to your original recipe. I doubled the amounts in grams to give me enough to fill a pump bottle. Because I was looking for winter-dry skin relief, I was hoping the aloe would do the trick. Your recipe called for 3% cetyl alcohol but I found it soapy the first time I used it,so cut it back to 2% to see if I liked it better. Not really; it changes the way a lotion goes on your skin but not in a better way, in my mind. Just my opinion; others might like it.
It turned out to be a really nice lotion, well worth repeating. Only problem is that my darned scale wasn't registering the small amount of EO and I think I put more in than I should have, so I smell really REALLY purty.

Bunny said...

Hm, is there a simple equation like the 0.25x for Polawax to determine how much BTMS-50 to add? I've actually got BTMS-25, and doubling it to make the same amount as would be in 50 often results in super stiff, powdery-ness....

Emma said...

Hi! You said that usually if adding something, take the percentage out of water.

What about if you dont use water in the recipe?

For example Im planning to do solid shampoo, conditioner and lotion bars and in the conditioner and lotion there will be no water (well, I dont have the recipes precisely but I have looked few and none of them contain water..)

But say I'll want to add a bit of colorants or plant/fruit powders or vitamins in the recipes (well, for example in lotion bar base there will be just butters and essential oils/fragrances) so can I just add them or do I need to take something out?

Also I havent decided how Im going to make the conditioner bar, u had a good recipe but a bit complicated for a beginner..
So, what ingredients to use that I get a solid bar, not liquid? How do I know if the finished product will harden up or stay in liquid?

Last two questions :D !
Can I use something other than lye in the shampoobars, I read that its not necessarily the best choice for hair..

Finally about p.H.'s... Hair, skin etc all have different ph's and im wonderin that if I make a product thats too acidic a bit more Basic and vice versa...

Why are all these things in percentages, Im so bad at maths!!! :D

Thank you so much if you have the time to answer, I can believe u are a bit busy..

Susan Barclay-Nichols said...

Hi Emma I don't use lye in my shampoo bars. You are thinking of someone else's recipe for soap based bars. And I don't think it wise for a new formulators to make massive changes in a product. Try the recipe the first time exactly as it has been written, then learn what each ingredient does and modify the recipe then. Look for another recipe that you think might be easier and try that. It might that bars aren't the best place for you to start learning how to make products.

K.Line said...

Thanks Susan, I ordered from Voyageur. I was hoping to avoid the shipping (it's pricey, even within Canada - as much as the ingredients I bought). But I'm glad to buy from a Canadian vendor and it took care of the few things I haven't found in TO.

Susan Barclay-Nichols said...

Hi Bunny. No, there isn't a rule of thumb for using BTMS of any sort. I generally use it at less than I would Polawax. For BTMS-25, you don't generally double it. I would for a hair conditioner as you're going for the amount of active ingredient, but not for a lotion. Sorry I can't be more helpful.