I use metric measures, so I'm not sure if that's 30oz fluid or weight, but here's a recipe for a mostly canola soap
I do all HP, so I have not seen how it will turn out CP.
92g coconut oil (3.245oz wt)
920g canola oil (32.45oz wt)
273g water (9.63oz wt)
132g lye (4.66oz wt)
(this is about 5% superfat, 27% water as a % of oils)
After 1 hour 100C in oven, add three table spoons of oat flour (see below), stir well.
To combat DOS, oxidation of excess oils, the soap needs added antioxidants.
Some options that are readly available:
Ceylon, oolong, or green tea brewed in lye water. Pros: complete penetration, high in antioxidants. Cons: may turn soap slightly pink/brown especially green tea.
Cinnamon, cocoa power, cloves, other spices with high ORAC: Pros: very high in antioxidant, smell nice (esp cinn). Cons: not very versitile, may not leach into all areas of soap.
Oat flour/crushed oats (added after cooked in HP): Pros: oat flour is low profile, no smell, versatile, excellent coverage (stirred well), adds white opacity to soap, adds creamy "oat bath" feel to soap. Cons: none, unless you don't like oats :wink: Can be hand crushed with mortar and pestal, or food processor, or grain mill.
To test if your soap will DOS or not: take samples of treated and untreated soap and leave in sun (but not too hot and melt it) for several days. Soap that will DOS starts to turn slightly yellow/orange after a day in the sun (UV really accelerates the breaking of weak double bonds in the excess canola oil that causes oxidation/DOS). Can be confirmed by comparing inner soap colour with outer soap colour as exterior will turn first. I leave for a few days to be sure. My oldest Canola soaps with above treatments are over 6 months old and going strong.
There are other commercial/artificial antioxidants as well, and I think Vit. E can be used.