wyeast states that their 1010 american wheat yeast should be fermented between 58F and 74F.
Experienced brewers always tell me low 60,s for an ale.I believe even Palmer gives similar advice.
What temp IS best? I sure made a crappy pumpkin ale at 72F.
First of all, you need to monitor the BEER temp, not just the ambient temp. There is a good bit of exothermic heat produced by multiplying yeast, so the beer temp could be +/- 5* warmer at high krausen than the ambient temp. So if 72 was your ambient temp for your pumpkin ale, your actual ferment temp could have been closer to 80, so yes, that would likely make a pretty fusely, headachey beer, especially if you spiced the beer as much as most homebrewers 
As a rule of thumb and very basic answer (I am assuming you don’t have means to control temp, like a chest freezer and temp controller), if you want a cleaner-tasting ale, keep the ambient temp in the low 60’s. I would do this on Am/Eng IPAs/APAs, bitters, most stouts, porters, ambers, brown ales, wheats/wits and most other styles.
If you don’t plan on getting temp control, I would first ask you to please reconsider, because it will catapult your beer from ‘homebrew’ to ‘beer’. Then I would ask you to please please please at least put your carboy/fermenter in a bigger tub with 4-5 inches of water in it, so the yeast can’t raise the temp during high krausen as much (more thermal mass).
If you want, after day 3 or so, move the fermenter into a more room-temp type place, and this will encourage full attenuation.
I’m a first-timer.
What does full attenuation mean? What does it do to the beer?
I just brewed my first batch yesterday using the Irish Red Ale kit and the fermentation looks to be going well this morning. The ambient temperature is 64 to 66 F and the “Fermometer” on the glass carboy reads… well I’m not entirely sure how to read it but the yellow (brightest) box is over the 70.
Is my ferment too warm? This is what you mean by “high krausen”, right? The time when this yeast is having a proper party?
I appreciate people leaving so much information to absorb here. It really makes me want to try a second batch and I haven’t even tasted my first!
(edited to correct the Fermometer reading)
Like Pietro said, a tub of water with some frozen soda bottles will go a long way in keeping the temps down. A picnic cooler and frozen bottles is a step up. See my signature line for variations on the idea.
mechler, attenuation is the percentage of sugar that the yeast consume and make alcohol with. Higher attenuation = more alcohol and less sweetness.
Temps, you just confirmed what Pietro mentioned about fermentation generating heat. 73* isn’t “bad”. Fermenting cooler will make for a “cleaner” tasting beer. If you can get the temps down to the low-mid 60’s it would be better. Most of the “off flavors” come in the 1st 2-3days. Some like to raise the temp after a couple of days to help increase the attenuation of the yeast.
high krausen is the point of most active fermentation. Krausen is the foam layer on top of the fermenting beer. High krausen is when it is at the largest size. So yes, the yeast are at the max party stage.
2nd batch. Get one started as soon as you can. When you bottle this beer, start a new one.
Bottling tip: Fill one soda bottle with your beer. Squeeze the O2 out and screw the cap on. As CO2 is formed the bottle will expand. No wondering what is happening inside the glass bottles. Let the bottles sit for 3-4 weeks. Then chill for 24 hours. Enjoy! You could try one at 2 weeks, but you may be disappointed.
I base the temp on the yeast strain I’m using for each batch. I have a spare room in my basement that is on its own Zone, so I set the thermostat to 2-3 degrees below the low end of the temperature range listed on Wyeast’s site for that strain and leave it there for the first 3 or so days. then I bring the temp up about 5 degrees and leave it for the rest of the ferment.
So if I want a “cleaner” – and though I’ve had a lot of craft beers, I’m not 100% what everyone means when they say “cleaner” – beer, I should get the temperature down? One way of doing that would be to increase the thermal mass and the high krausen temperature should be lower. I could go do that right now if that’s recommended.
I guess it depends on what “cleaner” means!
Strong alcohol flavor, solvent like and estery/fruity flavors are byproducts of warm fermentation. Depending on the style of beer, these may be desirable. But usually they are not.
The amount of these flavors that are produced depend on the yeast stain and the temp they are fermented at. A lot of these flavors are produced at the beginning of fermentation. The first 2-4 days.
http://morebeer.com/content/homebrew-off-flavorsSorry for the group of brewnerd terms…I throw them around like everyone knows what they mean. Everyone else has provided excellent explanations. Good luck.
