Beer: A Game of Temperature

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Beer! That delicious and refreshing beverage. When you drink a beer at home or in a bar, it is usually served cold. But does beer really taste better cold? Does temperature matter? Well, yes…yes it does.
From grains to glass, temperature matters. If you brew extract, or if you brew all-grain, temperature control is key to good beer. If you mash your grains too hot or too cold, you get different mouth feel and alcohol levels. Without a good hard boil, the sanitization and flavor profiles might be off. Cooling wort too slowly can cause some crazy bacteria in the wort. Your fermentation depends on good temperature and temperature control, as does storing the beer, carbonating, and so on. So let’s journey down beer lane and see how temperature impacts beer at all its stages.


Mashing at the right temperature for your beer's style.
When you mash your beer, you need to know if you want a heavy, medium, or light mouth feel. Mashing your beer at a higher temperatures – around 154 – 158F – will give you more mouth feel or body, but fewer sugars to convert to alcohol. The opposite is true for mashing at a lower – 147 to 153F – temp; you get more alcohol, but less body. And if you shoot for the middle of those you get a “balance” of yeast-friendly sugars and medium body. You might have to play around with the temps based on your equipment and beer style, but try mashing in each of these temp ranges until you are satisfied with the outcome. And remember to take style into account for the level of residual sweetness desired.


Isn’t a boiling pot of wort just as simple as turning up the heat? Yes! It is that simple, but it helps to understand the boil. Water and wort boil at 212F. During this process you add hops, some adjuncts, and what-not. This boil process not only helps in extracting the flavors and aromas of the add-ins, but also helps kill off anything that you don’t want in your beer. So, you might have cleaned, but you didn’t sanitize the wort chiller, or the mash/stir spoon. Well, rest your worry little head my fellow brewers. You can dunk the chiller or anything that won't melt in the boil and it will kill off the bad bacteria. Now, before you go crazy remember, this doesn’t replace the need for cleaning your gear. If you toss a gross moldy stir spoon or wort chiller in the beer, you’re going to be pissed when you find out you did ruin or nearly ruined your beer.


You know that you need to get the temperature down on the wort, but to what, why, and does it matter if it's fast or slow? "Pfft…I always cool my wort at the same speed. I set it and forget it, sometimes it takes me an hour or two. And it turns out fine!” Au contraire mon ami! If wort isn’t cooled quickly there is a risk of nasty bacteria growing during the cooling process. You may think it's fine--and it may be you are lucky--but eventually that process can ruin a beautifully crafted brew. Also, getting that temp down quick helps speed up the brew day. You can do the no-chill method if you are careful about it, but just leaving it in a kettle for 24 hours isn't the way to go about it.

Pitching and Maintaining

Maintaining fermentation temperature is critical to controlling yeast profiles and limiting off flavors.
Yeast are resilient little creatures. I have pitched yeast around 90F--while that isn’t what I would encourage--and my beer has turned out alright. The reality is pitching yeast at the temp of 70F or lower, depending on the strain, is necessary to ensure the right flavors are present at the end of fermentation and that you have a healthy and active fermentation. But it isn’t just as simple as pitching the yeast at the right temp. The beer must be stored and kept at a constant temperature throughout its life in the primary and secondary (when applicable). Yeast will go into suspension, happy and hungry, at the right temperatures. When temperatures drop too low or rise too high, the yeast might fall out of suspension or become stressed and then you risk off flavor, funky colors, or just an unfinished beer. Or you might have to shell out the extra duckets for some more yeast and re-pitch (*cough* – been there – *cough*). Just play it cool (get it?) and monitor your fermenting temperatures according to the information on the yeast packet.


The final stretch before getting some tasty homebrew.
If you carbonate your beer using CO2 or just using the old sugar method, temperature is important. If you store bottled beer with the sugar solution at temps under the 70F mark, then it is likely the yeast can’t pick up the courage or energy to re-start the fermenting process and properly carbonate the beer. But if you store around 70F and leave it for about 2-3 weeks, you should be golden, Pony-Boy. Using CO2 is a little different. You want that beer to be colder because the CO2 gas will be absorbed by the beer. There are charts all around the interwebs that help you identify the proper temp range and PSI for carbonating your beer; these charts are style-based too. As a rule of thumb, chill it overnight in your beer fridge and set the PSI to about 10. Most of the time, whatever your have the fridge temp set to is safe for the beer to chill and absorb the gas. Finding a beer carbonation chart is still highly encouraged so you can match it to style and prevent over- or under-carbonation.


Now you’re ready to drink the cold gold, or whatever you brewed. But serving it at the right temp is key to good beer. If you serve the beer to cold, you hide or exhibit flavors in the wrong way. If you serve too warm, you do the same. The best thing to do is dial in that temp. Serving temperature charts by style are out there too, just like the carbonating charts.
Some of the best beers have temperature in mind throughout the process.
Knowledge is the biggest battle, but now you know more, or maybe you’re refreshed and have remembered something you forgot. So relax and enjoy that brew. Cheers!
I was sort of expecting a "Storage" temperature heading, too. I prefer to keep my beer in the fridge but I have to let the remaining cases of bottles stay in our basement at about 18 °C.
Just to nit-pick a little bit further, I suppose water doesn't boil at exactly 212 °F when there are certain amounts of sugar dissolved in it.
I think the boiling section is a little thin. There's some amount of theory discussing how to ramp up your boil rate, not to mention what to do--or avoid--boil-over in the early stage. Also, the effect of rolling boils versus merely boiling on expelling various off-taste effects might deserve some mention.
I'll chime in here, since it seems my photo made into the article. The spoon in the airlock section is to prevent the blow off tube from kinking. Quick fix for the problem at hand. I've since started using another barrel as seen in the bottom of the photo and blow off tubes are a thing of the past.
I'm kind of surprised nobody commented on the gaping hole in the other door.
Quick question. My temperature for carbonation a bit low. If I stir up the bottle a bit and move it to a warmer spot, will it still carbonate? It's Benin in cool spot for about 7-10 days.