Originally Posted by smizak
If you think about it, the yeast can't be doing anything if they are flocculating.
Flocculating doesn't mean "falling out of solution." Flocculation simply means the yeast sticks to things - usually other yeast cells where, once the "snowball" gets big enough, they'll fall to the bottom. Higher-flocculating yeast clump together more readily, causing the beer to clear faster. But they also stick to CO2 bubbles, which causes them to rise to the top during active fermentation.
But they can be working during this whole time. The fact that they're sticking together doesn't mean they've given up metabolizing sugars.