Our esteemed colleague, Mr. JonR10 wrote in his post: here that:

Dude

Lighter fruitier blends brew better at higher temperature (in general)
Deeper chocolate comfort blends brew better at lower temperature


Example:
I have a lovely DP Ethiopian that I roast light to keep it's fruity notes. This makes a lovely fruited espresso at around 201-202°F. At 192°F it's terrible (sharp and acerbic, sour)

Some of my favorite espresso is chocolate bomb ristretto made from Yemen beans roasted into second crack and rested at least a week. I prefer to brew this coffee at around 192-194°F, but at 202°F it loses the sweet-chocolate-bomb effect.

This is very interesting and doesn't seem to make sense to me - since *usually* you roast fruity beans light and chocolaty beans dark - I assumed that you would also use a higher temperature for chocolaty and lower for fruity, but based on Mr. Rosenthal's statement above, it sounds like the inverse is true. I've never even thought to try brewing at that low of temperature...

Do others also find this general rule-of-thumb to hold true?

(standard disclaimer for the 'not always' crowd: OF COURSE I KNOW THAT THIS ISN'T ALWAYS GOING TO HOLD TRUE )

Light roasts hotter and dark roasts cooler has been the conventional wisdom among amateurs for a while. But now that pro baristas and roasters are pushing the envelope too, it's getting more complicated. Terroir roasts coffees very light and recommends very low brew temperatures (195F or lower) as well.

One simple reason that the old rule is getting cloudier is that everyone's espresso roasts are trending lighter. This is adding new data points. It could simply be that medium roasts (which we thought were light) require high temperatures, and that extreme roasts on either side require lower temperatures.

People also vary dose nowadays, and the interaction between the two is sometimes complicated too. I personally prefer boldly oversimplifying everything, but even I'm a bit stumped by all the new developments.

Thanks, Jim. At least conventional wisdom gives you a starting point! I just never imagined varying the temperature that much. I have stayed in the 201-205' range (easy for the HX), but will now expand my horizons a bit more on the lower bounds (more difficult for the HX), as it seems that above 205' is in char brewed territory...

The extra heat also helps to tone down the acidity, most of the time. Those fruited African beans tend to be quite acidic, the higher temp helps to down down the acidity most of the time.

This is a somewhat tricky subject, but a lot in the roasting department is dependent on bean density/size.

A Ethiopian Harrar, or a Yemen may act completely different in the roaster than, let's say a Brazil peaberry... or a Kenya Peaberry for that matter. And on the other end, the larger Margogype or Pacamara from El Salvador will roast differently than a (generally) large Sumatra.

Take the Harrar. If I roast on X curve and finish @ 433 F (drum temp) @ 14 minutes and Y curve at 433 F and 12:15,* and upon inspection the beans appear to be exactly the same in color/consistency... they are wholly different because of how the sugar development is manipulated. Sometimes I aim for a bright berry sweetness, but other times I aim for a dense/pulped berry effect, and while both roasts can highlight the particular berry notes of the coffee, they are different aspects of the berry, but berry nonetheless.

I had an espresso a while ago that I was brewing at 200.5 with in your face berry notes up front and milk chocolate notes in the finish, and I used the same exact blend roasted slightly different with deep intense berry notes up front and a background of semi-sweet chocolate at 198 F...

So when we speak of berry, or chocolate, it's "Which berry note?" or "What kind of chocolate?" that might matter more when thinking about roast and brew temps.

I'm not sure if that makes sense, but it won't be the first time.

I'm rambling. I'll go now.

* I am at high altitude. Take this into account if I ever talk about my roasting temps.

John P wrote:Take the Harrar. If I roast on X curve and finish @ 433 F (drum temp) @ 14 minutes and Y curve at 433 F and 12:15,* and upon inspection the beans appear to be exactly the same in color/consistency... they are wholly different because of how the sugar development is manipulated. Sometimes I aim for a bright berry sweetness, but other times I aim for a dense/pulped berry effect, and while both roasts can highlight the particular berry notes of the coffee, they are different aspects of the berry, but berry nonetheless...

This is interesting. My assumption (is where I got into trouble with the darker cooler thing earlier) is that the prolonged carmelization would give you the more 'dense / pulped berry' vs. the balls to the wall roast (err... 100% to finish) would give you the brighter (dare I say, uncarmelized??) berry?