I am going to guess it may be your soaping temperatures since your first batch with Wintergreen did not accelerate. Lard is extremely easy to soap with and I assume the is pig fat, you would be surprised some folks do not realize only pig fat is lard, and very slow to trace. I used to soap with a lot of Wintergreen and never found it to accelerate, and if you were using the same bottle of Wintergreen for all batches that were
Soapy Stuff not your problem. So I am thinking it is your soaping temp. Also, higher amounts of water can accelerate heating in batter, and heat can accelerate trace.
What I would do is lower the water next time to the lowest recommendation if using The Sage which gives you an approx 33%
Lye Concentration which you can read about here. I just posted her menu page since there is a wealth of information on DeeAnna's page. I also would advise investing in a Stick Blender the high shear is much more suited to soap making than a pastry blender since it does not whip in a lot of air into your batter. Pastry blenders work for making whipped soaps but that is a whole different procedure for another post.
So to sum it up Less Water, Cooler temps 100-110ºF, and Stick Blender. I like to blend to emulsion when the liquid and oils just come together then added in my fragrance then continue to light trace. But all that comes with experience.