Is it cooler for light roasts and hotter for dark ones? Or the other way around? Or neither?

I have encountered all of these different answers in my reading.

Matt

I think that the effect of temperature is similar to the effect of roast level. That is, higher temperature brewing will bring out similar flavors to a darker roast, and vice-versa. However, this does not mean that a particular roast demands a higher or lower temperature. Roast and brew temp are independent variables that you can use to control the resulting cup's flavor. To that end, you should adjust the temperature to your taste.

By the time you are brewing your cup, you no longer get to choose the roast level, and you instead adjust temp and grind. For example, if your coffee tastes sour, you probably don't want to drop the temp as that may further accentuate the sour; conversely, if your coffee tastes a bit charred, you might drop the temp a bit to balance the roasty notes. If the coffee is in the middle, then it's completely up to preference and the resulting coffee.

The key is to understand what effect the variables have on the outcome, which allows you to control the process. Following rules too strictly will only take you so far.

Good luck, and have fun experimenting!

mathof wrote:Is it cooler for light roasts and hotter for dark ones? Or the other way around? Or neither?

I have encountered all of these different answers in my reading.

Matt

Other way around...

The normal rule is lower temperatures for darker roasts and higher temperatures for lighter roasts.

Darker roast won't taste good at high temperatures whereas lighter roast can taste well with lower temperatures. You can experiment a lot with temperature but really dark roasts and real high temperatures will never give a good result.

Thank you all for the informative replies. That is just what I needed to know.

Matt

It's largely true that lighter roasts are inherently more acidy and sour than daker roasts; while darker roasts are more acrid and bitter than lighter roasts. However there are other reasons besides roast level why some roasts may be more acidy or display more burnt sugars than others and require taming.

Some baristas shortcut the dialing in process by assuming the truth of the generalization and starting lighter roasts with a hotter brew temp (to move them away from sour) and dark roasts with cooler water (to move them away from bitter.

At the end of the day, dialing-in is an empirical and case-by-case process. Beans don't read newbie forum threads and feel no obligation to conform to generalizations. The only temping rules you should take as gospel come from your palate.

Rich

I very much agree that the tendency is hotter for lighter roasts and cooler for darker roasts. To some extent, this can be seen as a way of compensating for roast, of getting more caramels and sweetness from light roasts or minimizing burnt distillate flavors from dark roasts.

However, do keep in mind that it's also a question of extractability. Light roasts produce a more intact cellulose structure of the coffee bean and thus require more temperature for an equal extraction. In many cases, complaints of a roast being "too light" can be solved by just extracting more aggressively.

I've been having fun playing with this since adding a PID controller to my Gaggia classic. I find that by lowering the temperature, I can get a more jammy taste out of dark roasts, where the fruit character was lost at the default/higher temperatures. Setting the boiler temperature above 106°C gives me burnt tasting espresso regardless of the roast level.

Listen to Rich.