Most crucial time to keep temperature below 75 degrees?

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Tankard

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My first AG just finished bubbling away in the carboy. On Wednesday-Thursday, the first day of fermentation, I avoided the ice bath and it started fermenting around 78 degrees. On Thursday, I put it in a water bath, put a wet towel around it, and I have been switching out ice water bottles and cubed ice. On Friday evening through Sunday morning, I went on a short vacation, but before I left I wet the towel thoroughly and I filled the water basin with a lot of ice.

It is now Sunday afternoon, and I have been adding ice and water bottles religiously. I also put a small fan on the towel to cool it off. I was not using a fan up until this point. The fermentation has now stopped completely.

Did my vacation away kill my beer? I wasn't adding ice from Friday afternoon/evening through Sunday morning. The temperature might have crept back up, but I am not sure.

I guess the point of this thread is to ask: Is temperature control the most crucial during the actual fermentation? Will maintaining the temperature now, after the fermenation has finished, make a real difference?
 
You want to pitch your yeast at the temperature that you want fermentation to start at. Depending on what you want, but I think 75 F is too high. The first couple of days are most important and you can let the temps increase some after that without negative effects.
 
You want to pitch your yeast at the temperature that you want fermentation to start at. Depending on what you want, but I think 75 F is too high. The first couple of days are most important and you can let the temps increase some after that without negative effects.

I always pitch my yeast way cooler than fermentation temps(45 for lagers-55 for ales(it's hot here in Florida)). I agree that the first days are the most important. If you can get to day 3 at 62-68 you will have a clean beer
 
Temperature is crucial during the initial stages of fermentation...the first few hours/couple of days, while the fermentation is at it's most exothermic (putting off the most heat).

From the brewer's handbook...

After the wort is run into the fermenter and the yeast added, the yeast begins building cell walls and reserves, which is referred to as the "lag phase." At the end of the lag phase, the yeast begins to divide. The first visible signs of fermentation is the appearance of fine bubbles on the wort surface at the sides of the fermenter. These bubbles gradually spread, until the surface of the wort is completely covered. After about 18 hours, the bubbles thicken and their color changes to light brown as the cold break rises to the surface of the wort. At the same time the specific gravity starts to fall as does the pH, with a subsequent rise in temperature and yeast count.

Eventually, maximum fermentation is reached (usually after 36-48 hrs) and the yeast surface is covered with a white foam of constantly moving pinnacles and crevasses as carbon dioxide rises to the surface. Gradually, the yeast activity slows, and the color of the head changes from white to pale cream as yeast start to rise to the surface to replace the foam. The yeast will rise for some time, eventually forming a thick covering.

So basically the first 2 days are the most crucial to maintain a lower temp.
 
I basically followed the same procedures as Brew Dude. Brewed on Friday night. Pitched the yeast at around 65-70. Then placed the whole thing in an ice bath. I used a bucket instead of a carboy and the suspense is killing me. No bubbles whatsoever in the airlock. Did I kill the yeast? Am I going to have to chuck the whole batch and start over? Or am I over analyzing and just need to give the yeast a little more time?
 
I learned early in my brewing experience that keeping the fermentation temperatures in the proper range for the yeast used is crucial. If you live in a temperate climate then a refrigerator and an external temperature control is a must have. You can fight this all you want but if you want really good beer then you just have to bite the bullet and get a refrigerator or freezer and a Ranco controller. The way I look at it is you either spend the money or possibly throw the beer out. The only sure way to have really good beer is to buy it or make it the best it can be brewed. It's a matter of choice. I do not want to sound harch but facts are facts. The yeast only work properly when conditions are right.
 
Could be a crap shoot, but if I were going to attempt that I'd also re-oxygenate the wort as well. Sorry about the bad luck, I hate leaving my beer un-attended. Dont know how many times SWMBO has said I have "problems" when I dont want to go away for long periods of time with beer in the fermentor.
 
Have you taken a gravity reading? That's quite a few days since you started it seems like, fermentation could have stopped because the beer is done.

I don't believe you should ever re-oxygenate a beer after pitching the yeast, it just oxidizes the beer.
 
Not to hijack the thread but ...

So long as the wort temp is within the strain's range, it should continue to ferment without problems, I understand that part. What about brief fluctuation of fermentation temps? I just brewed an extract wheat and I pitched wyeast #3068. The fermentation temp has stayed for the most part around 66°-68°(farenheit) using the ice bath method. I'm going out of town for a couple of days this coming weekend. I'm confident that the beer temp won't exceed 75°F by the time I get back. Would this brief fluctuation negatively affect fermentation?
 
On the White labs lable it says to start fermenting at 73-75. I would do this untill I see it starting then Drop the temp to 65-68. I guess thats right?
 
Would this brief fluctuation negatively affect fermentation?
My understanding is that pretty much as long as active fermentation is over, getting a little warmer is only going to help it attenuate. Obviously getting ridiculously hot (80+) is going to hurt your yeast, but getting into the mid 70s isn't going to hurt it.
 
Listening to some of the guys on the brewing network, they are always saying that temp fluctuation screws up the yeast. Fermenting at the top of the temp range for the yeast will create more esters and flavors from the yeast and using the lower end produces a cleaner taste. Jamil recommends starting below ferment temp by 5 drgrees, pitch the yeast then let it slowly warm up to your temp and hold it there as close to exact as possible.

With a fridge this is obviously quite a bit easier than in your bath tub.

Linc
 
I'm going to chime in with a question. Let's say I leave my beer sitting in the primary for 3 - 3 1/2 weeks because I don't use a secondary. Is it imperative that I maintain the temperature that is suggested for the yeast used (eg 60-70) or can the temperature be brought up (let's say to 75 degress) after a week or so once the vast majority of the fermentation is over?
 
On the White labs lable it says to start fermenting at 73-75. I would do this untill I see it starting then Drop the temp to 65-68. I guess thats right?


I wouldn't do that, I would start little low. Avery brewing and Fat Tire brew both said they start low and let the beer warm up from there.
 
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