Why did my lotion fail? Heating and holding post, but I'm getting so many questions about heating and holding this week, I thought it would be a good idea to remind you how important this process is to making emulsified products, including lotions and conditioners.
I know there are some well respected resources out there that say you don't have to do this, that heating your ingredients in the microwave until they are melted is enough, but it really isn't. Your ingredients can tolerate exposure to heat for a very long time - longer than we heat & hold, anyway - and they need this heat to make a lotion that will emulsify when combined and stay emulsified for ages to come.
The summary of heating and holding is this...We heat and hold our separate heated water phase and heated oil phase for 20 minutes at 70˚C/158˚F. Remove the containers from the heat, combine, then mix well with either a mixer or a stick blender. This process is what we do for every emulsified product from lotions to body butters to creams to conditioners and everything in between.
Why do we do this? To make the emulsion work better. If we heat and hold our ingredients at 70˚C for 20 minutes, we are assured that our emulsifier will be very oil soluble, which means it will create a water-in-oil emulsion that will eventually become an oil-in-water emulsion, which is very stable. We are assured our micelles will be a nice size, and we have eliminated many of the nasty contaminants that could ruin our lotion. In short, by heating and holding, we are ensuring we have a stable lotion that will remain emulsified and bug-free for a very long time!
When I teach classes at Voyageur Soap & Candle, we don't have a water bath to create a double boiler, so we can't heat and hold. We warm our water in the kettle and heat the oils in the microwaves. We use recipes I know will work well, but we still get failures. Why? Because we aren't heating and holding. You can make a lotion the microwave way, but you have a higher chance of failure than when you make it using the heat and hold method.
Why do some people forego the heat and hold? I really don't know. I've seen people say that our ingredients can't handle heat - they can! - and I've seen others say it takes too long, but neither of these are good reasons not to follow this process. It is the best practice for making emulsified products, and every professional recipe you see in a cosmetic chemistry textbook or from a large company that makes supplies has heated and held phases. It's standard practice to heat and hold because it makes for a better and more stable product every time.
I can't stress enough how important this process is to making a great lotion. I would say that half of the failed products that you write to me about are due to a failure to heat and hold. I'm not kidding about this. All those lovely ingredients, all that time, all that packaging could have been saved by heating and holding for 20 minutes. If you're not heating and holding yet and you've had a failed product, try it again with the heat and hold. If it's a well written recipe, that failure should be a success with this one small change.
Why we heat & hold our ingredients!
Why we heat & hold our ingredients separately
Weekend Wonderings: Heating & holding
Creating products: Heating & holding
What if you go over 70˚C when heating & holding?
How to heat & hold over a stove?
Does heating and holding damage our oils?