Managing Fermentation Pace

[TAK]

I just recently got a 10 gal corny for fermenting. Since it's so easy to take samples under CO2 pressure, I've been taking daily hydrometer samples to learn a bit more, both numbers and sensory, about the fermentation process.

Currently I'm fermenting an IPA, using Conan yeast for the first time. I don't have my exact notes in front of me, but this is the general picture: About 7-8 days it was down to 1.012&change. That might be done, let's give it a day. Each day since then, it's dropped just a bit less than 1 gravity point. So, I keep letting it ride.

Normally, I go by sight (used to use carboys) and experience with my IPAs, and by day 7-10, I'm racking to a dry hop keg. This one is looking like it might go 14 days before stable FG. I like to move AQAP with my IPAs, and I'm pretty sure I've heard John Kimmich say his are done in something like 7-10 with this yeast, too, or maybe it was less.

What variables can I manipulate to curtail this slow taper to FG?

First thought is oxygenation. I typically oxygenate with O2 for 0.25 sec per billion cells at 1L/min. That's just my reference point. I think it was 66 sec for this brew. Perhaps I should increase that a bit.

Temp, of course, is important. On this beer, I pitched at 64, held at 65 for 2 days, then increased 1F/day until 71, then held that.

Any other thoughts would be appreciated. With most beers, the difference between 7 or 14 days in primary, I could care less, in an IPA, time to glass is every bit as important as an ingredient as anything else, IMHO.

 

[mkeckjr]

I think temperature and oxygen are your best bet, as well as pitch rate. Looks like you have done a good job here of raising the temperature as fermentation has slowed. You may also consider servomyces as a yeast nutrient, since zinc is about the only nutrient (other than O2) that yeast need that is not readily available in an all-grain mash. Also keep in mind that professional brewers have the ability to manipulate some variables that we at the hombrew level usually don't have access to (e.g. pressure). I believe that's a key for how big places like Stone get an IPA from grain to glass in a short number of days. I think 14 days is very fair for an IPA at the homebrew level; I wouldn't want to rush it if I were you for acetaldehyde and diacetyl concerns.

Good luck, TAK

 

[WoodlandBrew]

Because you are oxygenating well it sounds like nitrogen limitation. For yeast to grow it needs assimilable Nitrogen (not gaseous) that it can use to synthesize amino acids. Without amino acids yeast cannot duplicate it's DNA which arrests growth and triggers preparation for stationary phase. Adding yeast nutrient, or DAP will help speed fermentation especially at the tail end.

 

[TAK]

Thanks for the good feedback.

Yeast Nutrient: I should have said, I use Wyeast yeast nutrient, which has zinc and nitrogen.

Pitch Rate: I didn't mention, but I do target a cell count and grow a starter on a stirplate to hit that. Perhaps I should play around with increasing that a bit for IPAs?

Off flavors: I definitely sample and don't move on until it's ready, temp control really helps with a good clean fermentation.

Pressure: I don't know much (okay, anything) about how pressure can effect a fermentation. I ferment in a corny, so head pressure is an option for me. Any input on what parameters to use for fermenting with head pressure, and what to expect from doing so?

 

[WoodlandBrew]

If you are looking for a clean and fast fermentation then increasing the pitch rate will help. You can also use as much as 3g of DAP for every 100g of DME in a starter to encourage growth. Also, after the first few days of fermentation the temperature can be increased and the fermentor can be swirled to help things along.

 

[BSBrewer83]

Also its possible you just can't control this yeast in this short of time. It's like trying to get your kids to grow up faster...