Finally Experienced A Stalled Fermentation

After years of brewing i just ran into my first 3 day lag phase for a stout to start fermenting.

Its sort of mysterious. Normal, unevental brewday. Im brewing two, 15 gallon batches, each brew day currently. Each batch has yeast grown from a slant, that came from a clean plate, and stepped up by 10x each step up. Normal, healthy starters, normal aeriation techniques.

Except this last session i had still wort for 3 days, while the other tank from the brew day had an IPA ripping away. The yeast was WY1028 London Ale.

When i checked on the tank the day after pitching and saw no activity and no drop in gravity i roused it up in case the 1028 flocced and dropped. Next day and same thing i top cropped from the IPA tank. Third day i roused again and now the stout is cranking away.

The thing that bothers me is since i top cropped with Pacman i dont know if the 1028 started up, or the tank is going off with just the pacman.

Wierd

 

Both beers turned out beautiful, btw