usage rates

[corrine025]

Ok so for the most part all of my FO's say the same usage amount so I use .8oz PPO in the lye calculator and go with that. I recently got black raspberry vanilla and it says the usage rate is 3.5%. Do I just take the amount of oils in my recipe and multiply by 3.5% or do I use the whole weight of the recipe including the water and lye?

 

[lsg]

I usually figure the percentage based on the weight of the oils and fats.

 

[cmzaha]

Was this the IFRA usage rate or the suggested rate from the supplier? I have never seen a BRV with such a low usage rate, but then I have not tried all BRV's. Other than fo's with known irritants such as mints, cloves, cinnamon etc I use most fo's and eo's at a rate of 6-6.5% of oils and fats which is approx 1 oz ppo.