Monday, June 6, 2016

Weekday Wonderings: How to use preservatives in our products?

Thanks for continuing to comment on all kinds of posts on the blog! The spam is abating, but it's still there, so I need to moderate comments for a while longer.

Please keep the comments coming for your suggestions for the one ingredient, five products posts! I let Raymond choose the next next ingredient, which will be xanthan gum, but I still need to choose other ones. (I won't be doing xanthan gum until July at the earliest as I need to experiment a bit more with it, so I'm looking for something to write about next!)

There have been a few questions about how to figure out how much preservative to use in a product. First, find out the suggested usage rate for your preservative of choice. My favourite, liquid Germall Plus, calls for 0.1% to 0.5%. I generally use the higher rate as I can't be completely sterile in my workshop. Find out into which phase you add it, then add it at that percentage to your product.

All recipes should total 100%, so everything in the recipe is included in that 100%. They shouldn't be 101% or 105% and so on. The total we want is 100%.

Before you correct me by showing me examples of where I didn't total 100%, I am well aware of my sometimes not-so-great adding skills and have recipes all over this blog that are over and under. I make mistakes all the time! When I write recipes that could use up to 1% preservative instead of my usual 0.5% preservative, I note that it might not add up to 100%. 

Let's look at this lotion recipe from the newbie section of the blog. Let's pretend that it doesn't contain any preservative. (This is killing me to write a recipe without preservatives!)

BASIC FIRST LOTION RECIPE
HEATED WATER PHASE
70% distilled water

HEATED OIL PHASE
15% oil (sunflower, soy bean, rice bran, or olive oil)
5% shea or mango butter
3% cetyl alcohol
6% emulsifier (BTMS or Polawax)

COOL DOWN PHASE
1% fragrance or essential oil

If you want to add liquid Germall Plus to the mix, you would add 0.5% to the cool down phase and remove 0.5% of the distilled water so the recipe continues to add up to 100%. Notice the difference in the distilled water amount.

BASIC FIRST LOTION RECIPE WITH ADDED PRESERVATIVE
HEATED WATER PHASE
69.5% distilled water

HEATED OIL PHASE
15% oil (sunflower, soy bean, rice bran, or olive oil)
5% shea or mango butter
3% cetyl alcohol
6% emulsifier (BTMS or Polawax)

COOL DOWN PHASE
1% fragrance or essential oil
0.5% liquid Germall Plus

If you wanted to use Germaben II, which has a suggested usage rate of up to 1%, then you would add that 1% to the cool down phase and remove 1% from the distilled water so the recipe continues to add up to 100%.

If you wanted to use Phenonip, which has a suggested usage rate of 0.25% to 1% in a lotion, you'd add 0.5% to the heated water phase and 0.5% to the heated oil phase, then remove 1% from the distilled water amount to keep the recipe at 100% total.

And so on...

If you find a recipe that doesn't contain a preservative, make sure you add one! There are so many out there that tell you to put the product in the fridge for a week. Don't. Add a preservative and feel happy that you've kept your product safe!

Related posts:
Preservatives section of the blog
FAQ - check out the calculating section
How do I modify a recipe when adding or subtracting something?

1 comment:

Anita said...

After discovering your blog some time ago, I became appalled at how many blogs, and now publications, tell people to keep their creations in the fridge. It's amazing how far people will go to appear "natural".
I appreciate you're blog being a voice of sanity and reason in the storm of irresponsibility.

~Mrs Spaceship