hi guys, so my question is "simple".
do you guys roast by time, sound (1st 2nd crack) or temperature??

I'm not a pro, but I would say sound and smell are most important. Color.
Temperature and time came second for me. I had a thought when I went into it where I wanted to get to with those, but I feel those come second to sound. They're almost the dialing in part. I could be way off, but it seems logical to me. Obviously, if your time is way out of line, you're not going to get optimal results due to underdevelopment or baking. So all of your things end up working together to get to where you want.

thanx for the reply, i think ur right.. i will be paying more attention to those two things.

Don't listen to just me either! Let's see what others say. Some might even say taste is most important

Gigimedrano wrote: do you guys roast by time, sound (1st 2nd crack) or temperature??

Yes.

I'm not good at roasting by my senses in real time. So, I go by temperature, time and sound; By color, only to a very minor degree and not at all by smell.

They all matter a lot.

The most important thing is to cup the coffees and understand how each and every variable impacts flavor.

For example: Time - shorter roast would preserve more acidity where as longer roast would give more body. Temperature - lower is obviously lighter, but temperature is meaningless apart from looking at it together with time and RoR. Throw in airflow and drum speed for controlling how much conduction/convection is used (for variables in density and water activity).

Sound is just...well...when 1C or 2C happens. Honestly, once profiled, the sound of cracks are almost irrelevant compared to the above variables. For example, it's nearly impossible to hear 1C happening in a Loring, but those who use it can roast incredibly tasty coffee with very high consistency.

But everyone has their methods Do what tastes good!

When you first start roasting, sound, sight and smell are the most important, even if your roaster is equipped with thermometers. Every roaster is different, even among the same brand. The bean temperature (BT) displayed is not the actual the actual temperature of the bean mass, just an approximation. ET is more reliable, but still dependent on probe placement. Even published temperatures for specific events, such as 1C, 2C and so on are merely averages obtained from a great deal of experimentation and experience. Knowing when the beans turn yellow (Dry), 1C, 2C, smell like grass, smell like bread, give off water vapour, give off true smoke...and so on, are important bench marks. With experience, you can corelate these to published norms and repeat the profile by temperature readings given you your particular set up. For example, my roaster reports 1C at around 178 to 182 C, depending on the bean. Neither of these figures align with published 'norms'. But, when my roaster hits a displayed 177, I know that the onset of 1C is imminent.

Interesting...

90% of time I go about 30 sec - 1 min after 1C ends.

Sometimes it's a judgement call if it's going past the temperature and getting darker than I wanted to get, or if 1C is over early and the development time seems too short, I'll let it go.

Not always easy to tell when first crack definitively starts or when it ends if there's a lot of sporadic spread out pops. Sometimes you have to default back to just time and Max temperature you want to don't want to exceed if the rest of the profile is normal.