cscade

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This is a deviousy simple question, but I think more than a few of you will kneejerk and go well, duh, it means this, only to second-guess yourselves.

When home brewers talk about fermentation temp control, what I hear them saying is environmental control. Keep the space your fermenter is in as constant a temperature as possible. Not the liquid inside the fermenter. This isn't hard.

However, as we are all aware, yeast produce heat energy as a side effect of doing their work. When a fermentation vessel is kept in a constant-temperature area (and I do mean perfectly constant) the temperature inside the fermentation vessel will still rise and fall in a curve from start of fermentation to completion. I've seen as much as 11f rise just from yeast activity in a fermenter kept in a dead-stable environment, depending on strain.

This is because air is a very poor conductor of heat. Regardless of how large the constant-temperature space is, as long as it is filled with air it will not dissipate (or normalize) the heat generated by the fermentation process.

Therefore, the only way to control the temperature of the fermenting wort itself is to actively dissipate, or apply, heat via some sort of metered mechanism.

Is this what we want? Will the yeast produce optimum results in a vessel that is allowed to change temperature, but only from, and relative to the heat the yeast themselves produce? Or, will they produce optimum results if their liquid environment is regulated to a constant temperature?

I ask this question only because until relatively recently on a historical scale, it would not have been possible for brewers to even cause the latter. Therefore, either we are now able to brew better beer than ever before by forcing the yeast to work in an artificial environment, or we are applying too much technology to what is really a simple problem.

When I hear the home brewing experts (John Palmer et all) talk about fermentation temp control, it is treated as the holy grail of good results. The most important element short of sanitation. How do we best apply it?

Boerderij_Kabouter

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It is a simple matter of measuring the temperature of the beer, not the air.

Use one of these:

Straight-Wall Stainless Steel Thermowell for Carboy or Fermenter


and a carboy hood, along with a temperature controller to maintain exact fermentation conditions.

Yes, it does make a huge difference.

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2P-Twent-E Simple Brew DITCHES 1 DITCHES 2 Fermentolagertaporator side-by-side ferm Twelve Hopostles Labels

tdavisii

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I go by air temp. You have some excellent points though. Still im not going to go any more crazy on my set up then what i already have

cscade

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So, then you're saying that we have only recently on a historical scale become able to brew truly good beer?

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As an aside to everyone, I'm well aware of the equipment and options available, and I'm fully capable of designing and building my own fully automated digital control system if I decide to.

This is really meant to be a theory discussion to see if we've gone too far in one direction just because we can.

I concede that it's certainly possible that yeast will perform best under artificial conditions. I just want to dig into this and see if there's any possibility for misconception here.

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Seeker Brewing Co.
est. 2008

Boerderij_Kabouter

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ahhhh.... now I get what you are saying.

I think that beer has made huge leaps forward in the last century. The discovery and invention for thermometers and how to control temperature have drastically improved more than just beer.

I believe Spaten Brewery was the first to realize the overwhelming importance of temperature and began controlling there ferment temps with ice houses to attempt a more controlled environment and fermentation temperature schedule.

The advanced temperature schedules used by many professional breweries do account for the different phases of yeast growth and metabolism, changing the temperature according to ideals. Many homebrewers do this to some extent (D-rest, raise temp toward end to manipulate the attenuation limits of a yeast, etc.) but in general we are not as advanced as the pros.

In general, temp control is proven (at least IMO) to produce better beer, more consistently. You can easily produce good beer just keeping the ferm temps in range, but my consistency and overall product quality improved greatly when I when to a completely controlled system.

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2P-Twent-E Simple Brew DITCHES 1 DITCHES 2 Fermentolagertaporator side-by-side ferm Twelve Hopostles Labels

broadbill

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Keep in mind that on a historical scale, only recently have breweries been able to brew year-round, thanks to proper temperature control. Before temperature control, breweries would either stop brewing for the summer or only brew styles amenable to higher fermentation temps (Belgian Saisons or Hefeweizens for example). Octoberfest beers where typically brewed as the last beer in the spring before the weather got too warm and then lagered them all summer in the cooler cellars before being tapped in the fall.

Even back then, brewers knew that proper temperature control was essential to making good beer to style, but were limited on ways to control control it. Not so anymore.
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In my experience, my beer have benefitted greatly from temperature control. Frankly, I'm making beer that is as good and ass fresh as the craft beer I can buy for $10/6 pack. I don't know if its going too far. I'd probably not be too excited about brewing if I was drinking a bubblegum amber that fermented at 85F.

I think one of the main reason why many new homebrewers aren't happy with the beer they are making (and ultimately drop the hobby) is because they lack the understanding and/or equipment for better fermentation temperature control. Now more than ever we have available to us the best ingredients and information out there to make good beer. Combine that with proper temp. control and you really can make quality beer.

Its really not about making yeast perform their best, its about making the yeast perform consistently and to produce a quality product. I'm all for using technology to accomplish this. I'm not sure what you mean by a "misconception" here....

broadbill

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I agree that the pros have way more advanced equipment than us homebrewers do. However, it is amazing how well us homebrewers can do, with some relatively simple equipment at our disposal!

Back to the OP, I guess I'm missing the point as I don't view fermentation control as a particularly invasive thing for the yeast, nor do I agree that we are necessarily imposing artificial conditions on them.

BioBeing

Recipes 

I think air movement is an important facet of temp control in the vessel. I keep a fan in my fermentation chamber to move the air, and the plastic thermothingy on the bucket generally agrees with the air temp from the Ranco thermosensor.

In the lab, I use both air temp monitoring and direct monitoring for bacterial growth. When I have a bunch of small scale growths to do, I put them in flasks and put the flasks in a shaker and just monitor the air temp. This works well, as there is plenty of air movement. I can shift from 37C to 42C or 16C with ease. When I grow my bacteria in a fermentor (10 L or 120 L), I have a thermosensor in the liquid. Temp is controlled by the computer passing water through a jacket that surrounds the vessel.

I generally consider the water-jacket-with-direct-monitoring more accurate (and would love a jacketed vessel for home use!), but air temp monitoring works just fine in 99% of situations..

Tonedef131

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I don't consider a temp controlled environment "artificial", since we are basically just simulating the temperatures that are ideal year round instead of being limited to only brewing during winter months. That is like saying since bacteria want to make a home in your wort, sanitation is making "artificial" beer.

In addition I would say that by today's standards, beer has only been great in the more recent years. I have no way to prove this but all historical texts I have read suggest that beer did not last very long due to high level of contaminates and was also smokey due to wood fired kilning. Malts were also kilned very dark in comparison to today's malts, making beers less consistent and basically cutting off all pale styles we now know of. If I had to guess I would say the beer we drink now is exponentially better than the beer people were drinking more than 100 years ago.

As for how I measure temp I put the temp probe up against the carboy and then tape a piece of foam over it. Every time I have measured the actual beer inside it was within 1 degree of what the temp controller said.

JKoravos

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Your use of the term "artificial" doesn't make sense to me in this context.

It's kind of like saying that any time you heat something up to cook it, it's artificially made because you controlled the temperature of the food.

I see your overarching point about technology, but I think aiming it at temp control is way off the mark.