Thursday, October 13, 2011

Creating products: Combining the two phases - mixing!

There are so many theories on how to mix your products after combining the two phases, so I'm just going to share with you what I do!

Remember that we need three things for a great emulsion...
  • chemical emulsification - this is where our emulsifier comes in. Pick a good emulsifier and use it at the right percentage! 
  • heat emulsification - in general, solubility of our ingredients increases when they are heated. Click here for more about the heating and holding phase of our products. 
  • mechanical agitation of some kind - mixing ingredients so they will stay emulsified. 
We need all three to come together to create a great emulsified product! With enough heat and mixing, we can make something that doesn't want to stay together become the bestest of friends for a short period of time  - for instance, adding a bit of glycerin to anhydrous lip balm or putting some honey into a whipped butter - but eventually the system will fall apart. We can use a chemical emulsifier and some mixing (think salad dressing), but without the heat, it tends to stay together for a very short period of time (hours, not days). We can use the chemical emulsifier and heat, but without the mixing, we have a horrible mess. (Yes, I realize there are some emulsifiers that work in the cold, but that's a conversation for another day!) By combining all three concepts - using a good chemical emulsifier at the appropriate percentage, heating and holding, and mixing the product well with a good mixer after combining the two phases - we can create an awesome lotion that will stay emulsified longer than a few hours!

How do we mix our products? A lot of the recipes you'll find will say something like "mix well" or "agitate" or something similarly vague. I've seen some manufacturers' recipes that say something like "mix for 10 minutes at 75˚C", which is very helpful, but how do you mix? We don't have fancy propeller mixers or those plates that move about - we have stick blenders, hand mixers, stand mixers, and milk foamers! So which is the best way?

I think to each their own - but the key is to mix the lotion well when you mix the two phases, then mix again when you add the cool down phase. I generally use a hand mixer on about 1 or 2 setting (which is quite high these days! I had to return a mixer because I couldn't control it at level 1!!!) for 5 to 10 minutes. I check the temperature as I go along because my workshop can get quite cold in the winter (see my posts in January and February! I couldn't get into the workshop because it was -7˚C some days and my distilled water was frozen and my oils had all reached the cloud point!), which can affect the rate at which my product cools! Then I make up my cool down phase, continue to check the temperature of my lotion, then add the cool down ingredients when it reaches 45˚C to 50C. I mix again for a few minutes. I let it cool completely, then bottle it.

If I use my stand mixer - for larger batches - I will combine the two phases in the large steel bowl, then mix on a lowish speed (no higher than 4) for a while. I'm not sure how long - it's generally until I remember to check on it. I will turn off the mixer and let it sit until the cool down phase phase, then let it mix again. I use the paddle for lotions and things of that nature, and I use the whisk for things like whipped butters and sugar scrubs. (And no, this isn't my mixer! I have a boring black one that's about 5 years old now. Isn't this lime green adorable???)

I don't tend to use stick blenders as my husband has declared them kitchen accessories, but I understand they can be quite effective when creating products. (If someone who loves stick blenders could share in the comments, that would be great!)

Click here for a post with some ideas for mixers, blenders, and other things that can help with this part of creating your products! 

So what do you think? How do you mix your products? Share your thoughts in the comments!


Tara said...

I've read a post from Perry Romanowski that we should also be heating our emulsions for an additional 20 minutes while mixing the two phases together. This was news to me! Maybe this is common knowledge to the cosmetic scientists. I've always tried to chill the mixture while mixing so that it would thicken rapidly and I could add the cool-down phase as soon as possible (impatience!). Maybe I've got to rethink this!

Lise M Andersen said...

I feel incredibly old fashioned-- I mix pretty much everything by hand unless I am doing a whipped butter or whipped cream (I have a whipped cream cleanser that I've done for years). Even then I only use a stick blender. I feel I have much better control this way. I also do whipping cream (the kind you eat) by hand too.

melian1 said...

i use a stick blender, in fact until this blog i didn't realize you could make a successful (long term stable) emulsion without high-shear blending!

i also don't spend 10 minutes (or more) with the sb, either. i think that if i continued with the sb until it cools, i'd have whipped cream rather than a nice lotion.

i create the emulsion, then let it sit and stir it with a spoon now and then until it is at the temperature i want for whatever i'm doing next. i have discovered that adding eo or fo when it is cooled down is not the best idea, as unless i hit it with the sb again for a couple of minutes, it will sometimes seep out and gather at the top of my tube of lotion (in other words it wasn't emulsified into the lotion). using the sb at cool-down causes all sorts of whipped cream effect and foam and stuff.

Ellbie said...

Quick question, can you over mix a cream? Thanks, Leslie

blendo said...

good emulsification depends on good blending-stick blending, or whisk blending. you can't get a good product by hand.
its like making salad dressing with oil and water- the longer you blend the better the emulsification-less and you obviously see the result!
just because it looks blened does not mean it is truly emulsified-blend longer!
you can purchase stick blenders cuisinart that has a fantastic whisk attachment-perfect for making small batches, but great for creams and lotions.

Nedeia said...

this topic makes me ask another question: honey in anhydrous products. yeah, I know, I know, we need an emulsifier, we need a preservative.. but there are people out there selling products like honey lip balm. and they swear that the product will not separate. they sell cuticle salves that are quite hard, and no trace of honey on the bottom. And the ingredients are "Natural Beeswax and Honey from our own hives, Shea Butter, Almond Oil and Vitamin E Oil.". now how do they do that? I never managed to incorporate honey with success in such a product. I know it will draw moisture from the air and some day it could ferment. I know the theory.... Are they just lying, or do they have a secret way of mixing? Especially when I know that you should not heat the honey at more than 40 degrees centigrade, if you want to keep any of its properties and not obtain a simple sweetener...

Anonymous said...

I'm sooo pleased to find this blog!! VERY grateful... keep it up...


Anonymous said...

Hi Susan thank you for the wonderful information so generously given here. After reading you post on blending lotions I wonder if I am over stirring my lotions. I have tried manual, stick blending & mixer but always end up with same result: even thought the finished lotion looks smooth when I put in the pots, the next day or so it starts to look like whipped milk cream that has been over whipped, kind of congealing which gets back to smooth texture after a bit of manual stirring but it doesn't stay smooth for long I have to keep on stirring every few days. Hope you can help me solve the mistery, thank you

moosie said...

In my few attempts at lotion making, the small tester batches I use a milk frother, but it is not very strong and produced a lot of air bubbles in my lotion, it eventually settled to a luxurious cream though. I also have only made high water content lotions, 70-80%. I did buy a ib with a whisk attachment and will try that if I make a larger batch. I've only used it for whipped body butter, oils only.

Also would love to know if it could be over mixed.

Another question, I've been reading all morning and mixing up a lot in my head.

when adding the cool down phase. Do you mix your oil and water phase first, then once cooled add the 3rd phase and then mix again?

moosie said...

ok sorry, just re read the topic and you mentioned mixing first, sorry I'm tired, early morning.

Thanks I've enjoyed reading up on your topics, very informative!!

But, I've never timed myself and wonder if I should

Leman said...

I am having a nightmare to try and find a mini hand mixer or a milk frother to mix my small portions! I broke my milk frother the other day which was this one I wasn't happy with it anyway as the power was quite weak! Also, my creams froth a lot when I use a milk frother. I mean I can hardly fill 50ml into a 100ml jar and I am thinking I must be doing something wrong or frothing too much or the fact that it is a milk frother!. Any ideas anyone? I have been looking around for a stronger one but can't find any. I make small portions that even a single blade hand mixer attachment would not suit. If anyone can suggest a good milk frother or else for mixing small portions I'd be very greatful.

Vanillagirl said...

Hi There, Susan thank you so much for sharing so freely with us all. God Bless you for this. I can identify with Leman. My emulsions are wonderfully stable (thanks to your info) but I find they end up with quite a lot of bubbles. I have been doing 500gm batches as I am new to this and am wondering if stickblending for 20 minutes to emulsify is too long. I subsequently add cooldown phase and sb a further 10 mins to ensure the ingredients are well mixed in. Am I blending too much? Thanks

Always.Looking.4.1.More said...

Hello everyone!

It seems this mixing part of what we do is getting to a lot of us. I've been looking, looking, looking, mixers everywhere for months, and what I've found are egg beaters and whisks that we can motion manually, and then there are the many electric appliances such as milk frothers, single-blade hand mixers, double-blade hand mixers, table-top blenders (for drinks), bread blenders, food processors, and a blending machine that was so big it looked like it might try to blend me!

I've noticed that a lot of foam/froth is produced when I make small batches (4-6 oz./118-177 ml. or less) of any formula that contains water. But I don't notice as much when I make a larger batch (16 oz./475 ml. or more). I use only electric mixers. I used the hand method once and felt it to be too time consuming. Though it was good exercise for my arms :-) So my experiences have me wondering if maybe this happens because we are all working with appliances that are too powerful for small batches. (No fault of ours, there just doesn't seem to be anything out there made for such small batches of formulating). The mixers on the market that people use to make one glass of something in the kitchen are made specifically for frothing because that's what we want when we make our drinks-- but not when we formulate. (My guess is that Lise's formulas that incorporate water usually turn out smooth without the excess foam/froth, and if so this is probably why). So, I see less product->shallow density allows more air to be incorporated vs. more product->more density->less air = less foam/froth, more smoothness. The only thing I have been able to think of to solve this is to use a slow blender/mixer that moves at the speed of a bread mixer, but is an appliance small enough to make small batches as well as large ones. And if it's on a stand of some sort it can be left to mix for extended periods of time so the formula gets mixed properly. OK, so I'm asking for lab-type equipment to be made available to us who formulate in the home. Oh well! :-)

There are some heavy chemists out here who might know the answer to this. Please tell us what you think, or know.

Thanks again for the blog Susan :-)

tonilinks said...

I know this post is old but I wanted to offer some input & I sincerely hope this helps someone out there.

I make lotion and soap. I used to mix everything by hand because I found that my hand mixer only whipped bubbles into my emulsions. I also experienced quite a bit of failed lotion batches using the exact same formula and process.

Enter the stick blender!

I can not begin to tell you how much of a difference the stick blender made in my creations; everything came out creamier and more consistent. No more lotion fails. Also, you have to be careful how you place the bell on the stick blender into the emulsion or you will trap air at the bottom of the container and whip it into the emulsion. Tap the bell on the bottom of the container and you will see the air bubbles rise to the top. Once the air is removed, I blend in 5 second bursts (low setting) for about 20 seconds. I let it cool for 3 mins then blend again, this time for a full minute on the low setting. While my lotion is slightly warm, I pour it into bottles but I don't cap them until completely cooled. I place a paper towel over the opening so that it can still release heat but keep "ickies" out. My lotions now have that commercial look and feel and I couldn't be any happier!

Hope this helps someone out there, even if it just sparks an idea to try something else. :-)