Saturday, September 10, 2011

Questions about mixing

In the small batch post, Annette asked: The problem I have is with the mixing - The oil phase is so small, it starts to re-solidify really fast! Also, what do you use to mix the small batches? I have tried just about everything but a hand whisk! Any tips for the mixing phase?

Before we get to the mixing ideas, please make sure you have heated and held your lotion phases for 20 minutes. Unless you're in my unheated workshop in the winter where it can get to -11˚C, your oil phase should have lots of time before it starts to solidify! If you are heating and holding and this is still happening, please give me some details because this is really strange.

I make a lot of small batches and I rarely use a stick blender, although a lot people swear by them. I find they're a pain to clean and my husband generally likes to keep them for food! I prefer my Black & Decker hand mixer with the regular mixing attachments and whisk attachments. I bought another one - Hamilton Beach - that comes with mixers that have silicone covers and one whisk attachment. Both were about $25 from Canadian Tire and Wal-Mart, respectively.

I know there are people who swear by stick blenders and others who swear by mixers, and although there some science behind the shear and speed and all of that, it really doesn't become a huge issue for lotion making unless you're into all kinds of strange emulsions or gels. My personal preference is for a mixer!

In the picture above, I'm using spoons and I do that for things like shampoo bars. For my surfactants, I always use a fork. There was a study a while ago - sorry, can't find the link - that going back and forth with a fork is more effective for stirring than going in circles with a spoon. I've been doing this for a while and I find it lessens the amount of bubbles in the product. I even have a large wooden spoon for those really big batches around Christmas time! 

Wendy had a similar question: It is very difficult to mix small batches. I have been searching for a stick blender with a disk-like attachment like one of those milk frother things but with more power. So far I find the easiest way is to use a milkshake mixer because you can lift the cup up high so the mixer reaches the very bottom. I bought one from Walmart for $20. I also was having the problem of the oil phase solidifying so I heat the stainless steel cup with oil phase in it and pour the water phase into the oil. I know lots of people say you are supposed to add the oil phase to the water phase but so far I have not had any problems. Do you think it matters which way you put the phases together?

Thanks for the great idea, Wendy! I've been looking for something like that for making emulsions with Sucragel emulsifier. I really don't like the emulsifier for lotions, but I've been dying to make the oily gel into a scrub or intense moisturizer.

As for adding the water phase to the oil phase and the oil phase to the water phase, on the surface we don't notice much of a difference. But under the surface, there are some differences. (Click here for the post on phase inversion.) For years, I added the oil phase to the water phase because the water phase container was generally larger than the oil phase container and it made more sense. I had exactly two lotion fails during that time: The first was because I didn't have the water and oil phase at the same temperature, and I forgot to put emulsifier in the second one. Neither seems to have been because I put the oil phase into the water phase. It worked, but it could have failed. If you're using an ethoxylated emulsifier - Polawax or e-wax, for instance - then the water phase into the oil phase will make for a more stable emulsion. If you're using a non-ethoxylated emulsifier, then it doesn't really matter.

Join me tomorrow for more fun with questions! 


MM said...


This is the little trick I use when I make my 'lotion prototypes' (30 grams): I work the two phases separately, as usual. When everything has melted, dissolved and been held for 20 minutes, I pour the water phase into the oil phase and heat 30 seconds more (be careful and prepared! The mix can spill like milk!). Then, I remove it from heat and mix with a milk frother for a few seconds, put the emulsion in cold water or ice and mix it for a few more seconds. Let it cool for a while, and mix more. Let it cool and mix until it's ready for the delicate ingredients and preservative.

Anonymous said...

Use a hand mixer but use only one beater. Fits great into small containers and works! Immersion blender fail with small batches. I second using canning jars- you can sterilize them easily and they are see tahru so use can see how your lotions and creams stand up to time and light

Nedeia said...

just one question: why don't we just add the oil and water phase into the same container, and heat the entire mixture? It will reach for sure the same temp, right? Of course, we do not add the heat sensitive ingredients at this point.

Just a thought...

Leman said...

I find stick blender not practical for small batches. Milk frothers would be great for small batches if only I could find one that's powerful enough! I need to look into milkshake mixers Wendy!

Susan, what would be the minimmum watt you recommend in a hand mixer? Do you think this hand mixer (160 watts) would be good enough? It comes with a disk-like milk frother attachment!


thanks so much!

melian1 said...

this is a great blog! i, too, have had trouble with the oil phase getting waaay too cool, sometimes even starting to re-solidify on the edges and outside layer against the cup, plus the sb fails with these small batches. so i'm glad to hear that a regular mixer, using one blade-thing will be high enough shear to emulsify. thx!!!

re the phase inversion, i think it isn't so much that it would fail to emulsify but that a phase-inverted lotion would be more stable over a longer period. that is my understanding from the reading i've done. none of my lotions ever last long enough to have tested this, lol.

re doing it all in one pot, on the dish a member posted her method of a pressure cooker lotion making, and she puts it all in, pressure cooks it for the proper time, and then sb's it in the pot. she says it works just fine. consult the dish forum for the info. it may be in the tutorial section, i'm not sure.

Elly said...
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