I have a confession to make...I am a yeast abuser. And I have been for years. Yes, I know all the "rules" and try to follow them, but sometimes I fail and resort to....yeast abuse. Recently I brewed a batch of my Rye IPA recipe on my Zymatic. Looking in the fridge, I saw some WY1450 with a date of June 26, 2015....10 months old. I thought "I could make a starter with that", but then I thought "Damn, that would take effort".
I simply took it out of the fridge and smacked it to see if there was anything left alive in there. Sure enough, the pack swelled. The yeast abuser in me was delighted...."hey, it's only 2.5 gal. of a 1.065 beer....that should work without a starter!". I know, I know....yeast abuse.
After the beer was done, I sanitized the smack pack, cut off the corner and poured it in. The wort was at 63F. I was nervous, but had faith in my laziness.
When I checked the beer 24 hours later, nothing.
24 more hours and still nothing.
About 12 hours after that, I saw the first signs of fermentation and thought "good enough".
12 hours after that there was a huge krausen that had formed.
After a week-10 days, I opened the keg I was fermenting in and saw that the foam had dropped quite a bit, but was still there. Took a gravity reading an got 1.030....damn, too high. Let it go for another week.
Yesterday I noticed the foam had completely dropped, so I crashed the temp to 33F. Took a gravity reading and it was 1.013...exactly on the money for a FG for that beer!
Poured the gravity sample into a PET bottle, put on a carb cap, and hit it with 30 psi. After 45 min. in the freezer, I had a cold, carbed sample to try. And it was delicious....perfect....exactly what that beer should be. Yeast abuse had paid off again. Sure it took a bit longer to ferment than usual, but that seems to be the only downside.
The moral of this tale is that you should trust your experience. It's great to know what the rules are, and I advise you to follow them until you have enough of your own experience to draw on. And once you do, go with it...trust yourself.
Try what seems to make sense to you, but in the end trust what you know to be personally true. And pour yourself a beer.