Figuring amount of ROE Per Batch

[Jersey Girl]

I am racking my brain trying to figure out how to use the ROE that I just purchased. I can’t seem to Understand how to figure such a minuscule amount or how to measure it. How much should be added to 27 oz (765.44g) of oil? Does anyone know the formula for figuring out the amount? What kind of scale would be capable of measuring this tiny amount? I use a My brain hurts. Lol. I use A lot of hard oils so adding it to them in bulk isn’t going to work.

 

[earlene]

Does your ROE bottle or the vendor indicate the carnosic acid strength of the ROE? That has an impact of how much you should use.

ROE is usually sold in varying strengths as measured by its carnosic acid content which can range from 2% to 7%.

See this for more detail and how to use ROE: Soapy Stuff: Rosemary oleoresin (ROE)

A jeweler's scale is useful weighing such small amounts. I tend to add it by drops into a freshly opened bottle of oil.

 

[shunt2011]

And just for reference, I add roe to my bottles when I open them. That way it's a measureable amount though I do have a jewelers scale.

 

[Jersey Girl]

Does your ROE bottle or the vendor indicate the carnosic acid strength of the ROE? That has an impact of how much you should use.



See this for more detail and how to use ROE: Soapy Stuff: Rosemary oleoresin (ROE)

A jeweler's scale is useful weighing such small amounts. I tend to add it by drops into a freshly opened bottle of oil.

I bought it from MMS. It‘s 5% strength. I did read Deanna’s article, a few times actually. I guess I need to get a jewelers scale and weigh out how much a drop weighs and go from there. Will a jewelers scale measure out the weight of a single drop?

 

[Jersey Girl]

And just for reference, I add roe to my bottles when I open them. That way it's a measureable amount though I do have a jewelers scale.

My problem with that is I have no stir Palm oil in a cube as well as 50 lb lard and Coconut oil that’s solid. There’s no way I can add it to those and I always use those oils in my soap.

 

[Mobjack Bay]

You can also mix the ROE into a carrier oil, e.g. 1 part ROE to 2 parts jojoba and then add 3x the calculated weight you need of ROE. It makes it easier to measure. (I got this idea from an old post by Zany). Jojoba has a very low SAP, so I don't bother to adjust oil weight for the small quantity used, but I do need to remember to add it to the label. It's probably easier to add it to the bulk oils, but I haven't quite made that transition.

ETA: the highly saturated fats are not as prone to DOS, so possibly less important to add ROE for them. I would like to know if that's the approach/assumption used by the more experienced makers who are adding ROE to their liquid oils.

 

[shunt2011]

I don't add it to my lard, coconut or palm they have fairly long shelf life. Only my liquid oils as they are more likely to oxidize.

 

[Jersey Girl]

I don't add it to my lard, coconut or palm they have fairly long shelf life. Only my liquid oils as they are more likely to oxidize.

So if I added it to my jugs of oil, what percentage do I use?

 

[DeeAnna]

Use the same percentage as you'd add to your soap. The dosage of ROE is based on the weight of oils, so other ingredients don't matter.

If you treat your fats with ROE before storage, don't add more ROE when making soap. One dose is enough.

I add ROE to my liquid fats right after purchase. I also add it to my home rendered lard and tallow while these fats are still warm and liquid from rendering.

Fats like coconut, palm, and palm kernel are shelf stable, so there's not much need to add ROE. The lard I buy is hydrogenated and treated with antioxidants and citric acid, so it too has a long shelf life and ROE isn't required. That's good since melting solid fat is a pain in the you-know-where.

 

[earlene]

Like DeeAnna, I only add it to soft oils when I open the bottles. I don't add it to hard oils, not even when I melt them to add to the mix while making soap.

 

[SeaSuds]

Can someone please babysit me through this ...if I have an 850ml bottle of oil, is the calculation 850 x .9 (density) = 765gms so I'm then calculating 0.05% of 765gms to get the amount of ROE?

Or...am I just calculating 0.05% of 850mls? Or... am I just weighing the bottle and contents and calculating the % from the total weight?

Or something completely different

 

[DeeAnna]

The amount of ROE is based on weight. The dosage I suggest for ROE is 0.05% of the weight of fats. That means --

ROE weight = Fat weight X .05 / 100

How did I get to this? "Percent" is a mashed-together English word that was originally written per-cent. The word "per" means to divide. The word "cent" stands for 100 (100 cents in a dollar, century is 100 years, etc.)

So whenever you see "per cent" that word is telling you to divide something by 100. So --

0.05% => 0.05 per cent => 0.05 / 100

Whether you weigh the fat directly or calculate the weight of fat using the specific gravity is up to you.