I've always stuck with 5% mostly because of availability, cost and because I have heard it can cut your lather, but I've heard of some people going up to 25% I just got a new batch, so with a bit more on hand, maybe I'll try upping the amount.
EG can I ask what you use most of the time. Are you a tallow guy? What is your heavier oil. If I'm digging hard just tell me to go away I'm just curious because I've always used high percent of Shea butter in my recipes. I was experimenting with 0% Shea and replaced it with beef tallow. I loved it. It was a harder bar in a shorter time frame seemed be extra bubbly. Just wanted to hear some other soap makers thoughts
I don't use palm or animal fats, so I use a combo of shea and cocoa butter for hardness. I've used up to 15% shea, but generally stick to 5% and use cocoa for the other 10%. I don't like to go above 15% butters as, like MrsSpaceship, I've heard it can kill lather. I love shea but would rather save large quantities for leave-on butters and lotions.
I always used up to 5%, mainly for hardness as I mostly make veg oil soaps.
There's one experimental batch that I'm using now, it's got 10% shea. It certainly didn't kill the lather, but I keep my SF low.
I tried tallow but I don't know what I'm doing wrong, I keep getting crazy ash and crazy looking bars, even at 20%.
That why I was experimenting. My regular recipes uses 15% Shea butter and I go thru it pretty fast, about 10 lbs every 10 to 14 days. Problem is my sugar scrubs have gotten so popular and they are like 50 % Shea butter. So I was just experimenting to see what I would have to do to get my soap Shea amount down to around 5% so I'm not using 20 lbs of Shea a week.
I'm one of those people that use 25% and I really like it. I add castor oil if I don't need a thin trace for swirls or sugar if I do for more lather...but even without them I love the bar and think the lather is okay.