Is Heat & Hold Necessary for Lotion?

[Zany_in_CO]

***** Continued from this thread (now closed):
https://www.soapmakingforum.com/threads/is-heat-hold-necessary-for-lotion.51563/page-2#post-695843

Ella75 said: So what do you think of this:
https://formulabotanica.com/6-reasons-why-the-heat-and-hold-method-is-a-myth/

I recently came across that article too, I also do heat & hold and would like to know what others think.

 

[lsg]

I do the heat and hold method. I first heat the oils and water separately, in the microwave and then put each in a preheated oven to hold for 20 minutes. I have never had a lotion fail with this method.

 

[The Efficacious Gentleman]

The take away that I got from that link is that it's not 100% required for the reasons stated most often, but even if some beasties survive the process it can help reduce the load put on the preservation system

 

[Cellador]

I heat and hold. My understanding is that, while it may reduce some risk of contamination, it also helps stabilize the emulsion.

 

[Saranac]

This article is written for formulators using more "natural" emulsifiers and not those using an emulsifier containing ethoxylated ingredients (i.e. emulsifying wax containing some form of polysorbate). Besides, I think calling "Heat and Hold" a myth serves much of the same purpose as click-bait; the writers are trying to sell you a product, which in this case, is their courses on natural-product formulating. With that said. . . .

I tend to agree with TEG; while heating and holding at 70C won't kill off everything that might be living in our ingredients, it will help to minimize some contamination. Additionally, as Cellador stated, my understanding is that heating and holding helps to stabilize the emulsion--but only when using ethoxylated emulsifiers. Interestingly enough, there's a recent thread on ChemistsCorner about heating and holding, and a member there makes reference to the fact that in order to stabilize an emulsion (with nonionic emulsifiers), the oil and water phases need to be combined BEFORE holding at temp (Source).

As anecdotal evidence, every time I'm tried to make an emulsion with ewax NF without heating and holding, it's failed. But BTMS-25 (cationic and non-ethoxylated) always holds well for me--even if I just through it all in a container, microwave just until the wax is melted, and move right into blending. I've also been playing with shea butter glycerides (self emulsifying, non-ethoxylated), and while I've yet to figure out a fool-proof way of emulsifying it into a cream with water, I've noticed that if it's too hot (70C) it breaks. Eventually, as the batch cools, it will come together nicely (with more mixing).

 

[madison]

I am new to lotion making but I'll take what Susan has posted on swift crafty monkey blog as I consider that more reliable source of information.

 

[Zany_in_CO]

@ madison: link?

 

[The Efficacious Gentleman]

@ madison: link?

A link to that site in general? Or to all of the times that she talks about heating and holding?

 

[Cellador]

Interestingly enough, there's a recent thread on ChemistsCorner about heating and holding, and a member there makes reference to the fact that in order to stabilize an emulsion (with nonionic emulsifiers), the oil and water phases need to be combined BEFORE holding at temp (Source).

After reading this, I'm questioning heating & holding now...grr. It certainly would speed the process....

 

[madison]

@ madison: link?

http://swiftcraftymonkey.blogspot.com/2010/01/if-youre-new-to-lotion-making.html

 

[soapmaker]

Interesting! I've always used the heat and hold method. I wonder...

 

[Saranac]

After reading this, I'm questioning heating & holding now...grr. It certainly would speed the process....

I should mention that I haven't tried holding after mixing the phases. . . yet!

Interesting! I've always used the heat and hold method. I wonder...

Keep in mind that I'm relatively certain that the article in question is speaking specifically about "newer" emulsifiers that are chemically different than "traditional" ethoxylated emulsifying wax, and that these "newer" emulsifiers may not need to go through a heat and hold stage (at least, not for the same reasons).

If you're using an ethoxylated emulsifying wax with an INCI that contains some sort of polysorbate, you should probably continue to heat and hold--or at least try a small batch to see how skipping this step affects your end result. But my take-away in all this is that Emulsifying Wax NF (e.g. cetearyl alcohol and polysorbate 60, or Polowax NF) should still be put through a heat and hold stage for emulsion stability. For me, the question that remains is at what point in the process is "holding" the most effective?

 

[DeeAnna]

^^^ What Saranac said. Spot on.

From my notes -- The temps of the oil and water phases should be sufficiently warm enough to make the most stable emulsion. Also for stability, the temperature of both phases should be a few degrees of each other when they are emulsified.

The ingredients in the oil phase need to be hot enough to fully melt and sufficiently hot enough to have a low viscosity. Holding the oil phase at temperature is not strictly necessary.

Ingredients in the water phase will become more sanitary during a 20 min hold, but heat-and-hold cannot and was never intended to sterilize. The real point of heating the water phase is not to sanitize -- the heating is needed to bring the water phase to the same temp as the oil phase for best emulsification. If you don't care to gain the sanitizing benefit, you could just heat the water phase to match the temp of the oil phase and proceed to emulsify.

I think the heat-and-hold method as commonly used is an easy to follow procedure for hobby lotion makers. A 20 min hold of the water and oil phases in a hot water bath is going to stabilize the temps of the two phases, ensure all ingredients are well melted and mixed, and give a person the best chance of making a stable emulsion. There's a lot to like with the method, again especially for hobby lotion makers. If one is making lotion on a commercial basis, matters might be different.

According to info about making lotions from Jane Barber, a cosmetic chemist --

"...You DO NOT need to hold the oil phase for 20 mins, however, we will need to heat the oil phase up to the same temperature as the water phase when you combine the phases for a proper emulsion. After the water phase has had 20 minutes at around 75C/165F and the oil phase is also at that temperature; slowly pour one of the phases into the other and mix 3-5 minutes with the stick blender on high...."

And this comment from Bob Zonis, another cosmetic chemist --

"...All other things being equal, a O/W [oil in water] emulsion with smaller oil droplets will be more stable than one with larger droplets.... It is a bit easier to break an oil phase into smaller droplets when the oil/water phases are hot - and the longer you can mix the hot phases together, the better. But - it also costs money to keep a batch hot, so about 30 minutes seemed to be the sweet spot. So, in current circumstances, if you aren't using a polymeric-type emulsifier, heat and hold will always make your emulsion better...."

 

[Zany_in_CO]

http://swiftcraftymonkey.blogspot.com/2010/01/if-youre-new-to-lotion-making.html

Perfect! Thank you!