Did a Newcastle all-grain kit from Austin Homebrew which came with Windsor dry yeast as my option. Brewing session went well, OG (1.053) right on the mark. Fermentation started vigorously within a couple of hours and slowed down as normal after a couple of days. Transferred to a secondary after 6 days, with gravity reading of 1.030. Took another reading after another 6 days with a reading of 1.025. Activity has been very slow, but not stopped during this period. Over the last 7 days activity in the bubbler has significantly picked up, closer to what it was on about the 3rd day after pitching. I've not seen this before, and while I understand Windsor to be a bit slower with lower attenuation, and while I'm anxious to hit a FG of closer to 1.011 per the recipe, does this "renewed interest" on the part of the yeast indicate normal activity, or am I looking at something nefarious? Frankly, the only other yeasts I've used are Nottingham and S-04 and never saw fermentation pick up like this after almost 3 weeks (3 -4 bubbles a minute).