No problem. I appreciate you trying to help me out. Since I have only done flavored ejuice with and without nicotine, I will try unflavored with and without nicotine. It's just very weird that the same harshness is there, even when I make different batches with different flavors. I have done a peach, watermelon, strawberry, honeydew, pineapple, and cantaloupe, all with the same results. No nicotine smooth, with nicotine harsh. I do like menthol, so I add 2% of it in all my batches.Sorry! I've been in and out today with visiting company in the house. I missed the 24mg base number. In your original post you talked about 100mg nic and then you ordered 24mg for comparison. It's been one of those days for interrupted conversations and I was thinking you added 4.73g of 100mg/ml nic.
Since you've tried the recipe with 24mg and 100mg nic base with the same results the only thing left is flavorings. PG and VG are pretty bland on throat hit even with nic added. I vape 3mg/ml unflavored nic base at 70pg/30vg quite a bit and it's smooth. I do hope that you find the problem.