Monday, February 2, 2015

Weekday Wonderings: What can we put into the cool down phase?

In this post, Learning to formulate: The cool down phase,  MSC asks: What is the maximum percentage of ingredients, specifically oils, that I can add in my cool down phase? I recently read that it is better not to heat Argan oil, which I would like to use. If I wanted 4% of my oil to be Argan could I add that during cool down, at the same time as my preservative and essential oils, or would that not work?

You're asking two questions here, so let's tackle each one individually.

Is it okay to heat argan oil? (Answer is originally from this post.) Yes. There is no reason not to put it in the heated phase of our products. There's a perception out there that some carrier or exotic oils are fragile creatures, that they can't handle heating and holding at 70˚C/158˚F. They can. The smoke point on these oils is much much higher than the heating and holding temperature, and you are doing them no harm by heating them.

Related posts:
Does heating and holding damage our oils?
Heating, holding, freezing, and thawing our oils
Why we heat & hold ingredients
Why we heat & hold our ingredient separately

The second question is how much can we put into our cool down phase? The cool down phase is generally under 45˚C/113˚F, and we put all the oil soluble and water soluble ingredients that can't handle heat into this phase. This is where we put our volatile ingredients, heat sensitive ingredients, and fragrance or essential oils. How much can we put into it? We want to put as little as possible into this phase in emulsified products. There isn't a hard and fast rule about adding no more than x% of the recipe into this phase, but the goal is to add as little as possible.

Why? Because these ingredients don't get the benefit of the heating and holding phase, and we really want that process to happen as it's an essential part of creating a stable emulsion. (Yes, you can create an emulsion by putting your ingredients in the microwave long enough to melt, but it isn't going to be stable, and runs the risk of separating or failing!) If you have a ton of oil soluble ingredients in the cool down phase, you aren't heating and holding them, which means they might not emulsify as well.

So to answer the question - argan oil should go into the heated oil phase with your other oils and your cool down phase should be as small as you can make it!

Related posts:
How do you know into which phase we should add an ingredient?
How do you know how much of each ingredient to add to a product?


MSC said...

Thank you for your post Susan-- that is very helpful.

Birgit said...

I have been wondering about that myself, so thanks for clarifying this. Sometimes I feel like I want to add what feels like 10% of ingredients into cool down phase (extracts, silicones, tocopherol, panthenol, essential oil etc), and have noticed that after a while something seeps out. I guess those would be the oil soluble extracts and other goodies that did not properly emulsify. I will try to keep my cool down phase smaller in the future, and see if I still notice the seeping out.
Get well soon,

A KK said...

That was an interesting discussion. I don't know if you are aware or not about the new formulation of going preservative free with some of the Lush products.
They claim to have come up with "self perserving lotions"

I looked at their UK site for more info and they state that:

Of course, it’s not practical to sell only solid products, which is why we have continued to use synthetic preservatives in our creams and lotions. However, we’ve now found a way to keep the amount of ‘free water’ – which is the water that’s left over once the chemical reactions have taken place – to a minimum, meaning that even our moisturisers can become entirely self-preserving. “We’ve now developed a set of formulation parameters that have allowed us to develop a range of self-preserving systems,” says Daniel. “By balancing the levels of water, butters and oils, safe cleansing agents and other beautiful natural materials we can create cosmetics where all the materials used are there for the benefit of the skin or hair. The dynamics of the formula are carefully balanced in order to produce a beautiful product that is effective, practical and long-lasting, without having to utilise a preservative system.”
Taken from

I would like to know what your thoughts are on this new innovation and what an impact it will have on the cosmetic industry

A KK said...

OOPs meant to say skin care industry.

Elisabeth said...

How about freeze-dried fruit extracts? I've had a couple of lotions separate when I've used freeze-dried raspberry powder in the water phase (all else equal, with a previously tried emulsifier, so I'm leaning towards the fruit powder as the villain.) It's behaved well enough when I've mixed it with fluid ingredients in the cool down phase, such as panthenol and/or Multifruit BSC.
And I believe I've seen hydrolysed proteins going into the water phase as well as in the cool down phase, do you have any particular insights into that?

Take care! Elisabeth

Susan Barclay-Nichols said...

Hi A KK! If you want my honest opinion, I'll share this with you. I don't believe Lush. If I could see an actual write up of this technology they've discovered - and no one else has - I'd be a happy woman. But until then, I wouldn't buy anything from them without a proper listed preservative. (I'm sure saying this will get me in trouble with the Lush enthusiasts, but you wanted my opinion!)

I guess the question that I have is why are they still using parabens when they have this technology? Why aren't they doing this with every recipe they have? And why do some of the recipes in which they have removed the preservative look identical to the way they were before? Wouldn't there be a change in the recipe?

Hi Elisabeth! I would always use powdered extracts in the cool down phase as they don't tend to like heat. I don't know if that was the problem with your previous lotions, though.

As for proteins, I have put them in the cool down phase in the past because I thought they were very fragile, but I read that they should be heated as they could be hard to preserve if we don't, so I put them in the heated phase now.

Michelle D. said...

Hi Susan,

I've just been reading several studies on silicones and have learned they can be added successfully to the heated oil phase. DowCorning cautions to verify the fatty alcohols and butters are melted prior to adding dimethicone. The release is here:

This would help reduce the percentage of the cool down phase. I was wondering what your thoughts are?


Susan Barclay-Nichols said...

Hi Michelle. I've heard they can be used in the heated phase, and I see from the article you sent, that they are using them in that way. Using them in the cool down phase works for me and I can't see a reason not to continue to use them that way as I haven't had problems with emulsification because of the silicones. It seems like more work to use them in the heated phase, to be honest! :-)

RobinLindsay said...

I recently purchased some Argan Oil from Lotioncrafter and am putting together a spreadsheet with information regarding temperature restrictions, solubility, and usage rates. I looked at the MSDS sheet from Lotioncrafter and it says under Stability and Reactivity: "Product is Stable under normal circumstances. Just avoid heating at more than 180°C (food use), at more than 60°C (cosmetic use). Product does not decompose under normal conditions." I understand the flash point is rather high (240°C) but I thought that was just the point where the oil catches fire. Could it be that the oil is damaged at lower temperatures? With a temperature restriction of 60°C in cosmetic use, it would not be able to be heated and held.

Thanks for any clarification!