Monday, May 13, 2013

Rosemary Oleoresin Extract (ROE)

I like to use some oils that are soft and have a shorter shelf-life in my recipes, like sunflower oil.  In the past, I have used a mixture of Vitamin E (.5-1%) and Vitamin C (.25-.5%) to help retard rancidity in my soaps.  I haven't had many issues with rancidity to date, which has been great!  Due to how quickly I've been using my oils lately, I just add the extract directly to my master batch when the master batches are prepared.

However, when I was digging around on the internet for something else unrelated, I stumbled across this interesting study which seems to indicate that while Vitamin E & C have many great skin benefits and can help defer rancidity in oils in general, Rosemary Oleoresin is a better performer to preserve shelf life of oils in soap.  The article is written by Kevin Dunn (author of Scientific Soapmaking) and is a very interesting read:

Since the ROE rancidity effect appears in this one study (I am trying to find other studies which will confirm these results), I wanted to give it a shot in some soaps to test drive it a bit.

I made a 2-loaf batch of a repeat of the soap I made for the mica swirled top challenge, and added the ROE to the oils at .5% of the oil weight.  However, while I was mixing the oils to trace, the ROE didn't mix in well with the rest of the soap batter.  There was a layer of reddish orange stuff floating on top of the batter, even as I stick-blended it through medium trace.  I didn't think to take a photo while this was going on.  Now that I've re-read the articles, I have definitely over-used the ROE in my soap batter (recommendation of .02-.1%, depending on where you're reading).  I also tried to soap cooler than normal - around 75 degrees, instead of my usual 110 degrees or so. Since these kind of challenges go in threes, I had also forgotten to put in the EO blend I had mixed up for this batch, so I'm going to make another batch tonight WITH the scent this time :)

What's interesting is that when the soap batter was poured, the top of the yellow layer looked pretty green.  However, when I went downstairs tonight to take pictures after it had set up for a couple days, the green layer on top has gone away. It must have re-absorbed into the soap?  Very strange.

Here you can see a very slight variation of color between the top and the side.  However, I had just unmolded the soap, so the color difference could be the more wet soap vs the drier top.

In this picture you can see the color a little, too, but the top doesn't look green like it did when it was soap batter.

Here's a picture of how they turned out cut.  I really like these colors for the scent, even though these ended up unscented :)

Another show-off picture

Here is a good blog post which looks at the anti-microbial claims of ROE and whether it can function as an effective general preservative:  (in short- it is not a sufficient stand-alone preservative system).  For anyone interested in cosmetic chemistry knowledge, Susan's blog is a great resource, and has some excellent starting recipes for lotions, shampoos, etc.

I've been researching what happens if one uses too much ROE in soaps, but I'm not finding a ton of information.  This soap will be relegated to personal use until I can determine whether it is safe to use.

Also, I had a friend over a few weekends ago to help me take some pictures and show me how to use my little old point-and-shoot.  She took some amazing pictures with the natural sunlight, and she showed me some good ways to set up and use my camera, too.  I'm so happy with how the pictures turned out!

Some Chocolate Mint cupcakes - they look like edible cupcakes!

The Challenge #3 soap - mica swirled tops

Yuzu / Orange soap

Soap Challenge #2 - Elemental Swirl

This one I took myself :)  Rosemary Mint.  It looks similar to the ones my friend took with her SLR camera, even though you can tell hers are better.

Have a great Monday!



  1. Interesting blog! I have thought about using ROE in my soaps as well. I may just try it. I love the pics by the way. I really like how you used the natural light :)

  2. Interesting information, Chrissy! I have already read that some EOs like rosemary, clove, thyme, tea-tree serve as natural preservatives, so it's always good to use one of them in soap.
    But I have never used rosemary extract, I suppose the effect is stronger.
    Your soaps are luxurious, lovely pictures too!!! The soap with mica swirled tops is my favorite!

  3. That's so interesting about the RO. I have heard of adding rosemary oil extract to your soaping oils to prolong shelf life, is that the same thing as rosemary oleoresin? Hadn't thought of adding it to soap though, great experiment! I love those picture you and your friend took too, very beautiful!!!

  4. Wow, all of those soap photos are gorgeous, Chrissy! The cupcakes do look totally edible, and I love the mica swirl soaps. I've never tried ROE in soap. I haven't had any problems yet with soaps going rancid, but I generally use them within a year. It will be interesting to see if the ROE prolongs the shelf life of your oils and soap.

  5. Thanks for all your comments - I have also not noticed any DOS problems with this current formula, but I had noticed them with some other formulas with other oils. Since I have reformulated and have been using shorter shelf-life oils, I want to make sure they do not go rancid for friends, family, others who have the soaps, since I know they will not necessarily use them right away. I had been using the combination of Vitamins C & E, but the study was interesting to me in how the cold process soaping techniques reduce the effectiveness of those two vitamins. I'm surprised that ROE seems to hold out better, so I'm looking forward to testing these bars out over time to see whether they hold up.

  6. The blog link you provided is for Rosemary Essential Oil, not ROE. They are different and your article may lead to confusion on this point. The oleoresin extract is simply an anti-oxidant, not more (antimicrobial, etc.)


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