Home Cosmetic Science Talk Formulating Cream turns cakey after 24hrs?

  • Cream turns cakey after 24hrs?

    Posted by JackDerrington on October 7, 2019 at 2:57 pm

    Hello everyone,

    We are using a formulation that’s been suggested by a client. Initially (after cooling down) the texture is very creamy and desirable.

    After 24-48hrs, the top layer of the cream gets very cakey. 

    Here’s a relative breakdown of the formula:

    Water: 28.50%
    Aloe Vera Liquid: 20%
    Glycerin: 7%
    Oil: 10%
    Oil 2: 4%
    Oil 3: 2%
    Emulsifying Wax NF: 5%
    Stearic Acid: 3%
    Shea Butter: 7%
    Liquid SF Complete: 4%
    Boswellia Serrata Extract: 9%
    Fragrance: 0.5%

    =========

    Thank you!

    Pharma replied 4 years, 7 months ago 11 Members · 23 Replies
  • 23 Replies
  • ngarayeva001

    Member
    October 7, 2019 at 7:49 pm

    Knock out aloe and the extract and see how it is. If no issues, add them back at ‘claim’ amounts (less than 0.5%).

  • JackDerrington

    Member
    October 7, 2019 at 10:04 pm

    @ngarayeva001
    Thanks for your input!

    We did formulate without the aloe and extract and the end result was still cakey. I don’t know if there is a common culprit when it comes to caking, like not enough emulsifier or a bad balance.

  • ozgirl

    Member
    October 7, 2019 at 10:33 pm
    Is the sample covered (eg. in a jar with a lid) after you make it? Could it be that it is simply drying out and losing moisture from the top layer.
    Do you have a photo of the “cakey” texture?
  • JackDerrington

    Member
    October 7, 2019 at 11:32 pm

    @ozgirl

    Thank you for your response. Yes, each jar is immediately covered/sealed with a lid.

    Three photos below:

    (Apologies, the photographs posted out of order)

    #3 Shows some of the cakey quality. It’s not creamy. However, if I mix it up, it returns back to a creamier texture. I will attach photos below after some casual mixing.

    #2/#4 Shows after a little crude/casual stirring, it becomes a little creamier again. (More consistent and stable?)

    #1 Shows the lid that has been on this sample since it was poured.

    Thanks for any ideas or input. I am going to do a bunch of tests to figure out what needs to be changed, but any suggestions would be appreciated to accelerate this process.

    Thanks!

    Jack

  • tanelise

    Member
    October 8, 2019 at 12:03 am

    @JackDerrington I almost wonder if you have too much Shea butter. It looks “pasty” on your fingers 

  • ozgirl

    Member
    October 8, 2019 at 12:07 am

    To me it looks like your cream is just reaching its final consistency. Your levels of stearic acid and shea butter are reasonably high and these raw materials may take a day or two to solidify. I would recommend reducing the shea butter and stearic acid to see if the final consistency is better.

  • ngarayeva001

    Member
    October 8, 2019 at 5:52 am

    Another thing you can do, is swapping Stearic acid to 2% of cetyl alcohol and reducing Shea butter to 2%. You can also add 0.3% of xanthan. All these together should make it more elegant.

  • Chemist77

    Member
    October 8, 2019 at 12:55 pm

    Add a little base to neutralize the stearic acid and see if it gets any better. Or add a little ceteareth 20 which might help as well. In addition to all the above recommended suggestions. 

  • JackDerrington

    Member
    October 8, 2019 at 2:36 pm

    Hi All,

    Thanks so much for the assistance. I have done two more test samples. Right now (as with the rest of the creams), the texture is almost as desired and will probably reach it within the day. But we will see how it works in the next 24-48hrs.

    Images for reference:

    1. Demonstrating how the samples are sealed: Cream in, Inner Liner applied, Lid sealed.

    2. The texture of the cream is relatively smooth.  A little more solid and it will reach the desired texture (I expect this to happen today).

    3. I tried two new formulas to solve this problem. I eliminated all the stearic acid in one trial, and reduced the Shea butter to 2% in another (replaced with oil) while keeping the Stearic Acid at 1%.

    We will see. Please let me know if you have any other suggestions! I am getting a new batch of Xanthan Gum in soon, and will try to neutralize the Stearic Acid in further tests if this proves unsuccessful as @Chemist77 suggested.

    Thanks everyone. Will update soon.

  • Sponge

    Member
    October 8, 2019 at 3:13 pm

    What’s the purpose of neutralizing stearic acid in this situation? I assume you’re only neutralizing it, not saponifying it eg. sodium hydroxide -> sodium stearate. How will it influence the product?

    Also, I agree with @tanelise the shea butter may be causing the cakey consistency in the proportions you used if you don’t control the cool down.

  • JackDerrington

    Member
    October 9, 2019 at 4:25 pm

    Hi all,

    28 hours later update:

    Both samples have the same caking issue. Photos below.

    1. Shea Butter 2%, Stearic Aid 1%. Still caking/pasting. I am beginning to wonder if it’s the way the formula is being agitated after combining water and oil phases. In this photograph, I just dipped my finger into the cream and removed it, revealing the cakey/patchy texture below.

    ===============

    2. Stearic Acid 0%. Shea Butter 7%. (Shea Butter at original percent). In this photograph, I used quite a bit of the cream to reveal more of the cakey texture below.

    Both of these have become cakey and airy. I am beginning to think it may be an issue with how it is mixed or added to the container? What do you think?

    ================

    3. After very little stirring with a wooden stick, the cream immediately reverts to a nice creamy texture. This is why I am getting a feeling it may not be a formulation issue?

    Thanks all for your help and ideas!

    Jack

  • EVchem

    Member
    October 9, 2019 at 6:25 pm

    @JackDerrington  you might be onto something with processing- what kind of equipment are you mixing with? I have seen that kind of texture in a cold-process cream I made (so none of the same ingredients as you). We eventually figured out the texture came from the equipment….a kitchen aid blender with a beater attachment  ( don’t judge-when I started in my lab we only had that mixer and a waring blender)

  • tanelise

    Member
    October 9, 2019 at 7:46 pm

    @JackDerrington, what’s the temp of the cream when you seal the jars?

  • JackDerrington

    Member
    October 10, 2019 at 11:49 am

    Hello all,

    Okay last night did an additional test. Using the original formula posted here, I hand-mixed until 85 degrees Fahrenheit and then poured one sample, then poured an additional sample and hand-mixed that individual sample in its individual jar.

    Photograph: On the left, just poured the sample in. On the right, poured the sample in and mixed with a mixing stick. (There are different amounts, I didn’t split it appropriately but I believe the texture/caking issue shouldn’t be affected by a difference in volume).

     
    I will be trying some more formulas using different agitators to see if that’s the problem. I will update after the usual 24 hours or so, or whenever any caking becomes apparent in any of the samples.

    Jack

  • JonahRay

    Member
    October 10, 2019 at 5:59 pm

    I’ve actually seen something almost identical in products I was developing. What’s interesting is it only occurred in these small glass jars that I was using because I ran out of any type. I assumed it was that they weren’t air tight and so the cream was basically drying up. Maybe try putting the formula into another container? Maybe the surface is drying out like suggested earlier.

  • Pharma

    Member
    October 10, 2019 at 7:13 pm
    Which oils do you use?
    Some ingredients such as stearic acid and waxes can change crystal structure and/or crystal organisation. This takes about a day or two and may result in a weird “gritty” structure which gets destroyed upon mixing but can reform after some time (similar to bentonite).
    You could prepare only your oil phase and let that sit for a day or two and see what happens. Doesn’t always work, though.
  • belassi

    Member
    October 10, 2019 at 11:50 pm

    Could it be ostwald ripening?

  • Zaf

    Member
    October 11, 2019 at 12:30 am
    How are you cooling this? Are you just letting it come back down to room temp naturally?
    Shea butter is pretty much the only thing I’m super familiar with. And that’d be my initial guess as well. Also: perhaps for the other oils — when you have lots of different fatty acids they can do weird stuff on cool down.
    I’m not sure how cool down effects the stearic acid/ect, but Shea is a temperamental $#@& and does not like it when it’s cooled slowly.
    If it won’t destabilize the other ingredients, try cooling it quicker (cold bath, fridge, freezer - pick one). I usually throw my butters in the freezer for about 15-30 minutes (you probably really only need like 5 minutes… I’m assuming that jar is about 2oz, it’ll cool quickly). That’ll just get everything to solidify as is.
    I wouldn’t even consider that since you tried it with 2% Shea… but that you’re getting the texture you want on the top and then the texture you don’t want further in, my brain wants to say maybe it’s how it’s cooling. I’ve had liquid oils try to separate from Shea with minor temp changes (heck pure Shea does that on its own!). If any ingredients don’t contradict it, always try quick cooling with stuff that involves Shea.
    Disclaimer: I am not a chemist, just a person who works a lot with Shea.
  • JackDerrington

    Member
    October 11, 2019 at 3:59 pm

    Hi All,

    Thanks for all the suggestions, ideas, and dialogue. 

    Recent Update:

    36 hours later, the latest change (original formula with different agitation) seems to have solved the issue.

    @tanelise

    I generally seal the jars when the cream is relatively warm (80-90f)

    @JonahRay Thanks for this suggestion. I did try another container with the same results before (before I posted here). I will definitely keep this in mind in the future though!

    @Pharma

    Sweet Almond Oil, Avocado Oil, Jojoba Oil, Emu Oil, Sunflower Seed Oil, Hemp/Seed Oil, Vitamin E Oil.

    @Zaf

    The latest batches I have tried, I get about 4 samples. One of them I put in the fridge, another I keep in a lab kept at around 75f. Similar results with both (the caking). But I will keep in mind what you’re saying about Shea! I will run a batch and cool it quicker (even though we have apparently solved this issue), and let you know the results. I’ll run it with the original Shea level to keep things consistent. You are saying to agitate for a few minutes then put it in the freezer/fridge/icebath, correct? How long to agitate? Thanks!


    I’ll keep you updated on how things continue at 48 hours and beyond.

    In the mean time, can anyone recommend smaller scale but still industrial quality agitators? I will be doing research for this shortly. Thanks again everyone for your time and attention and help.

    Cheers,

    Jack

  • tanelise

    Member
    October 11, 2019 at 4:28 pm

    @JackDerrington, thanks for sharing the updates and pictures. It has been interesting seeing the transformation.

  • Zaf

    Member
    October 11, 2019 at 5:16 pm
    I tend to whip the heck out of it till it fluffs up, cool, then whip/blend again, and another cool if I feel like it after it’s been packaged. I mostly do that because then I can see how stiff it is but I’ve had more luck that way. Any whipping/blending adds a little heat and I usually do the second whip on a lower speed to not introduce much heat. Shea seems to appreciate some tempering and I’d generally suggest it with waxy butters (so like Cupuacu and Sal too). Shea’s notorious for causing funky texture - usually grittiness, but I’ve had the quality you’re talking about a time or two in a batch which tempering and quick cooling seems to fix.
    I was thinking about this and you’d think the wax would improve that quality of Shea… should break up and bind the fatty acids I would think. (Excuse me if I’m saying that the wrong way)
    But if you got it figured it then you’re golden!
    God I love Shea but it’s such a pain in the butt.

  • Pharma

    Member
    October 11, 2019 at 7:05 pm

    Belassi said:

    Could it be ostwald ripening?

    Unlikely because the observed effect is too fast. More likely to be creaming, coalescence or flocculation but then, the cream would/should separate at one point. What about some sort of phase inversion or at least change in emulsion type? Given the roughly 50:50 oil-to-water phase… I was thinking about a microscope or centrifugation to test for emulsion stability.
    Though that effect does look to me more of a “molecular” issue such as that weird behaviour of shea like @Zaf describes.

  • Pharma

    Member
    October 11, 2019 at 7:08 pm


    Sweet Almond Oil, Avocado Oil, Jojoba Oil, Emu Oil, Sunflower Seed Oil, Hemp/Seed Oil, Vitamin E Oil.

    Unsuspicious…

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