June -- Any given setting for "water as % of oils" doesn't translate consistently to a specific lye concentration because the math to do this translation depends on the average saponification value for the recipe you're using.
Different recipes => different average sap values => different lye concentration for the same 38% water as % of oil (or whatever number you use in place of the 38%).
The 28% lye concentration I gave in my earlier post is based on a recipe that has 38% water as % of oils AND a typical mix of soaping fats. If you use a recipe that is higher in coconut oil, you're going to see a higher lye concentration -- as high as 31-32% lye conc -- for that same 38% water as % of oils. If your recipe is higher in a lower sap value fat such as olive oil, your going to see a lower lye concentration -- as low as 25-26% lye conc.
Different recipes => different average sap values => different lye concentration for the same 38% water as % of oil (or whatever number you use in place of the 38%).
The 28% lye concentration I gave in my earlier post is based on a recipe that has 38% water as % of oils AND a typical mix of soaping fats. If you use a recipe that is higher in coconut oil, you're going to see a higher lye concentration -- as high as 31-32% lye conc -- for that same 38% water as % of oils. If your recipe is higher in a lower sap value fat such as olive oil, your going to see a lower lye concentration -- as low as 25-26% lye conc.
