The smell of pumpkin pie spread into the kitchen as I opened the door of the mini fridge holding my fermentor…
It was only the third day since fermentation had started. A nice steady rate moved the bubbles inside the airlock. The controlled increase in temperature over the last couple of days nudged the yeast into higher activity as fermentation neared its end…
This increased activity cleaned up the beer and removed many of the fruity esters that could fight the spices and pumpkin flavor of the beer…
I’ve used this technique successfully in many batches where I want a clean yeast profile… but this alone won’t cut it…
You need to pitch the right amount of yeast… for my pumpkin ale, the amount of yeast I needed was more than the vial contained… and to answer a question that was posted on my blog ‘why do you make a yeast starter?’… this is why… yeast growth…
24 hours before pitching, I took the yeast from the vial and dumped it into 1 liter of fresh wort (1.040 S.G.)… overnight, the yeast population grew by approximately 50%… this extra amount of yeast reduced the amount of esters produced at the beginning of fermentation… I’ve used this along my low to high fermentation temperature technique to brew beers with a clean yeast profile… but these two tips alone won’t cut it…
When I first started doing starters I decanted as much wort as possible by crash cooling the starter to drop the yeast to the bottom of my Erlenmeyer flask. Later I realized that while yeast population grew, my yeast were ‘inactive’…
There is a difference between growing yeast, and activating yeast. Wyeast smack packs are designed to ‘activate’ yeast… If you crash cool your yeast starter to separate it from the wort, you may have to add a bit more wort an hour or two before pitching to ‘activate’ the yeast again… kind of like activating a smack pack…
Pitching ‘active’ yeast into your fermentor reduces the amount of esters yeast produce at the beginning of fermentation…
These three techniques combined will reveal a clean malty profile in your beers by reducing the esters that would otherwise fight it… one or two out of the three techniques alone has a fraction of the total effect…
… as Aristotle said “The whole is greater than the sum of its parts”…
Synergy…
It’s what we based our home brew training programs on…
Cheers!
