I ask this question as i am new to snuff and it is common practice in the pipe tobacco world. I have half a tin left of J&H Wilsons top mill which would be at least 20 years old (opened earlier this year) and it is really great. Darker in colour to new Top Mill that i have recently purchased and has a deeper spicyness to it. Could this just be variations in manufacturing between now and then? Do any of you deliberately do this? Thanks!