Well, the temperature range of fermentation is determined by YOU, as it's whatever range you happen to have the beer in the fermentor.
Your question is kind of difficult because it's largely meaningless. Though I suppose it's easy enough to infer that you were asking about what particular factor determines the *ideal* temperature range.
But the problem is that it's still a pretty meaningless question, as you haven't really provided any criteria for what constitutes "ideal".
Now, I could just do the easy thing and answerable "yes" to your question, and it wouldn't be wrong... though again, it'd be pretty meaningless, because, while the particular yeast strain is *always* a factor, there is really only ONE instance where it's the ONLY factor - which is if you define the "ideal" ferm temp range as the absolute min and max temps at which the the strain is able to convert sugar to alcohol, rather than die or go dormant.
Unfortunately, that's a really wide temperature range, and it's generally pretty useless information for a brewer. Notty might be able to work at 110°, but it starts making the beer taste like crap *well* before that.
So that's why I say your question is kind of meaningless. So what defines the ideal/optimal temperature range that matters to you? Because the factors that DO end up determining the ideal temperature range (in addition to the yeast strain itself) will depend entirely on just exactly what you want the fermentation to accomplish.
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TL;DR: Sure.
He was asking a question regarding my post. You need to let me and him determine if it’s “meaningless” or if there is a "problem" as you put it.
Did you write that post when you were drunk?
His question is a reasonable one ... and the actual answer is:
Yes, the yeast strain DOES determine the temperature range available to you ... although the temperature you decide upon for your end-result is dependent on additional factors.
This is an opportunity to draw an instructive distinction regarding the use of temperature in fermentation.
You really couldn’t figure that out?? DOH!!
Go ahead and take a yeast like WLP720 or Eau de Vie or a Cotes des Blancs and try and get that started in a low 60 degree environment and see how far you get without raising the temp or suffering a stall. In that circumstance you can bet your ass the yeast determines the temperature range that is available to you.
Further, you state:
“there is really only ONE instance where (the strain of yeast is) the ONLY factor - which is if you define the "ideal" ferm temp range”.
That is dead wrong. Contrary to your assertion that there “is really only one instance” ... there is NO instance where there is only ONE factor in the choice of yeast. We are talking about an informed decision and understanding what one is doing ... not just “shooting from the hip”.
Temperature, metabolic activity (e.g. the ability of 71B-1112 to metabolize malic acid), flocculation characteristics, nutrient requirements, how the choice of yeast affects fruit maceration, alcohol tolerance, strength verses undesired (“wild”
yeast strains and a whole host of biochemical characteristics that provide for, amongst other things, the production of esters which influence aroma and flavor are part of the selection of yeast.
If what you really meant was that yeast selection and fermentation temperature are specific to the overall characteristics you are trying to develop in the end-product. Then just say that without the obfuscating blabber.