[tomsawyer]

I was reading this last issue of Zymurgy and saw the recpe for Ofest that was BOS of the Boneyard Brewoff.  The guy said he pitched at 60F and then chilled to 50F after a day.  That struck me as being a little unconventional, but its hard to argue when his beer won BOS at an established contest like the Boneyard.  anyone else doing this successfully?

I was bummed not to be able to judge last year's Boneyard, they moved it to January and I had already made plans.  Good bunch of people in the BUZZ club and they bring some excellent judges.

[Kaiser]

I think there is no clear evidence that pitching below fermentation temp is going to produce significantly better beer than pitching above and chilling the beer. It's generally seen as best practice to pitch below fermentation temps and that's what commercial brewers do. But they don't have the same constraints that home brewers face and for them chilling to a low wort temp might be easier than for some home brewers.

Kai

[davidgzach]

60F is not that far off the recommended lagering range either and it only took a day to get to 50F which means he was in the range in ~12 hours.  IMHO if he pitched at room temp it would have taken twice as long which would have meant much more time out of the preferred range to produce off-flavors.

Dave

Edit: Saw it was AFTER a day that he chilled to 50F.  Still, 60F is a LOT closer to preferred than 68F. And I think the higher activity at 68F would bring the fermentation temp even higher as well.

[Pi]

Just my 2 cents, but wouldn't pitching at a slightly higher temperature get the yeast going quicker, thereby reducing the lag time and chance of infection? I don't know enough about yeast behavior to substantiate this but if given a choice between off-flavors vs. infection I would rule in favor of the latter.

[denny]

Just my 2 cents, but wouldn't pitching at a slightly higher temperature get the yeast going quicker, thereby reducing the lag time and chance of infection? I don't know enough about yeast behavior to substantiate this but if given a choice between off-flavors vs. infection I would rule in favor of the latter.

yes, it does that, but at the expense of flavor IMO.

[jmcamerlengo]

Just my 2 cents, but wouldn't pitching at a slightly higher temperature get the yeast going quicker, thereby reducing the lag time and chance of infection? I don't know enough about yeast behavior to substantiate this but if given a choice between off-flavors vs. infection I would rule in favor of the latter.

yes, it does that, but at the expense of flavor IMO.

Me too Denny, I have also found that pitching warmer and cooling to lager temps afterwards produces more diacetyl, which means doing a D-rest, which means another step...which I dont care to do.

[Pi]

Wow, Thanks for that knowledge you guys. I get fresh hefe and find I almost always have to do a D-rest. I wondered where it was coming from... Now I Know!! Next batch I'll pitch cool and warm up to fermentation.

[musseldoc]

I also believe that when yeast detect a large drop in temperature, especially a 10 degree or greater swing, they start to go to sleep.  This can result in some off flavors as they reinforce their protein coat, as well as under-attenuation issues. A yeast that is pitched cool (40-45F) and warmed (48-52F) with the wort will be active and increasing in metabolism. 

[tschmidlin]

I also believe that when yeast detect a large drop in temperature, especially a 10 degree or greater swing, they start to go to sleep.  This can result in some off flavors as they reinforce their protein coat, as well as under-attenuation issues. A yeast that is pitched cool (40-45F) and warmed (48-52F) with the wort will be active and increasing in metabolism. 

Some yeast will start to flocculate when the temperature drops.  There is some strain dependency, but it is generally true.

Yeast don't have a protein coat - there are proteins in the cell wall that are sometimes referred to as coat proteins, but this is not the same thing.

[a10t2]

thereby reducing the lag time and chance of infection?

Whenever someone says that something will increase the risk of contamination, the counter-argument is going to be: Why is your wort contaminated to begin with?

[Kaiser]

Tom,

Is the temp drop and flocculation effect also true for lager yeast? In my experience an active lager starter will not settle in a 40 F fridge, for example. I always have to let the yeast ferment most of the sugars before it starts to flocculate.

Kai

[majorvices]

In my experience starting the fermentation warm on lagers does two things. First it can produce ale like esters, or flavors that are not characteristic to lagers. Second, if you cool an actively fermenting beer it can cause the yeast to throw diacetyl. Can you make a BOS lager by pitching warm and cooling during active fermentation? As the case shows, obviously. Doesn't mean you could not make a better beer though by following "proper" protocol.

A beer like an Ofest has enough malt to hide some fermentation imperfections and of course some lager yeasts do ferment fairly clean at 60 degrees anyway and if you do a d-rest you can clean up diacetyl. So certainly it is a practice that works for some, but in my opinion and experience it is not the best way to approach lager brewing.

[tschmidlin]

Tom,

Is the temp drop and flocculation effect also true for lager yeast? In my experience an active lager starter will not settle in a 40 F fridge, for example. I always have to let the yeast ferment most of the sugars before it starts to flocculate.

Kai

Yes and no, there is strain dependency for the varying conditions in the beer.  If a 10F drop in temp caused flocculation in all strains that would solve a lot of headaches

I have read that in some lager strains flocculation actually increases as the temp goes up to ale fermentation temps.  I've also read that 50F is optimal in some lager strains tested, and that flocculation can be inhibited in some lager strains when it gets very cold.  It is also inhibited by the presence of sugars, so actively fermenting yeast are less likely to drop out even when there is a temperature change, which explains your experience.  And then there are all of the other factors that affect flocculation in a strain dependent way, like pH and ABV.  Bottom line is you have to know your strain.

The 50F number is kind of interesting - it implies to me that the proteins/complexes responsible for flocculation may be very similar in ale and lager strains and they are structurally affected or maybe expression is repressed by the temperature.  If you drop an ale strain 10F from fermentation temps and it floccs out, you are nearing the optimal temp that was found for lager flocculation in some strains.  If you drop a lager by 10F from fermentation temps you are inhibiting flocculation by moving away from the optimum.  This is conjecture of course, but it would be fun to study.

[erockrph]

Tom,

Is the temp drop and flocculation effect also true for lager yeast? In my experience an active lager starter will not settle in a 40 F fridge, for example. I always have to let the yeast ferment most of the sugars before it starts to flocculate.

Kai

Yes and no, there is strain dependency for the varying conditions in the beer.  If a 10F drop in temp caused flocculation in all strains that would solve a lot of headaches

I have read that in some lager strains flocculation actually increases as the temp goes up to ale fermentation temps.  I've also read that 50F is optimal in some lager strains tested, and that flocculation can be inhibited in some lager strains when it gets very cold.  It is also inhibited by the presence of sugars, so actively fermenting yeast are less likely to drop out even when there is a temperature change, which explains your experience.  And then there are all of the other factors that affect flocculation in a strain dependent way, like pH and ABV.  Bottom line is you have to know your strain.

The 50F number is kind of interesting - it implies to me that the proteins/complexes responsible for flocculation may be very similar in ale and lager strains and they are structurally affected or maybe expression is repressed by the temperature.  If you drop an ale strain 10F from fermentation temps and it floccs out, you are nearing the optimal temp that was found for lager flocculation in some strains.  If you drop a lager by 10F from fermentation temps you are inhibiting flocculation by moving away from the optimum.  This is conjecture of course, but it would be fun to study.

This is interesting info. This is the first time where the whole "slowly ramp temps down from a D-rest to lagering temp" makes sense to me. By spending more time at whatever temp is optimum for your yeast you could enhance flocculation over just cold crashing from D-rest to lagering.