Post By flynnaus
Post By Dimal
Post By barrel21
Post By Koffee_Kosmo
KK Roasting Time
I have been using my KK roaster for the past two years, typically my roast times have been approx. 20 mins when using similar beans. I recently purchased a Heatsnob and thought I would go to the next level and record profiles and alter roasting times. After reading other posts it appears that a quick heat to the first crack is better. If I apply full heat up to just before the first crack I can roast to completion in 12-13 mins. This seems to be acceptable to other roasters, but I am finding that when I use a blend of beans that the colour profile is varies from very dark to light which was not an issue when I was using a slower more gradual 20 min roast for my 500-600 gm batch.
As the KK roaster applies a lot of heat on the surface should I be using a more gradual heat profile?
I am keen to know how long other KK roasters would roast a 500-600gm batch for?
Depends on a few factors including bean type, batch size, turbo oven power, ambient temperature and what mods you might have applied. I've been using a KKTO for 10 years and have a batch size of 450g which seems to be the bestbalance between coffee needs and roasting efficiency. Roast time is about 17mins but I preheat to 170° before loading and lower RoR to 6-7° per min between 140 and 160° then full bore until first crack. I lower RoR to around 4°/min stopping shy of second crack at ~217° or 218°
Originally Posted by barrel21
I haven't done a 500g+ batch for a while but i reckon the time would be 20min+. The thermodynamics of my roaster could be very different to yours.
I haven't been that happy with my roasts recently so I'll try the full bore until first crack profile.
Gentler profiles do work better for bean blends though so if you're looking to experiment with batches, try reducing your overall profile time by, say a minute or two each batch, then record your impressions after tasting in the cup results. I wouldn't ramp up towards 1st-Crack too quickly as beans of different densities in your blend may not roast evenly through the beans themselves.
A bit of a 'suck it and see' approach is best...
Previously I wasn't perfecting the art of roasting and use a much gentler heat, if I use full power I get a RoR close to 15-22 depending on the factors you have mentioned. I now have my roaster enclosed in a wooden box rather than wrap a fire blanket around it and have minimal heat loss. Previously I have done a Brazil/Colombian/Ethiopian blend with good even colour when I finish the roast between 218-225 deg C. Now the Ethiopian is black by the time I reach 115 deg. I always preheat to 200 deg C, but next batch I will follow a profile as recommended by Flynnaus, which is probably similar to how I use to roast.
Now I can measure RoR and roasting time and the segments more accurately I will revert back to a 20min/500gm and see if I get even colour with a slow heat up at the start and then make modifications as recommended by Dimal
For blends I use this methodology
Different beans have different moisture content plus consider the different age of beans in the blend
So the method I employ is add beans in roast chamber and agitate at a low heat of 125 C for up to 10 min
This does not roast the beans it normalises moisture content of all beans
Then start time on your roast by the method you use and prefer
If the blend has organic African beans then you may have some light beans at the end of the roast and that is normal
Will try this on my next blend to even the moisture, recently when I was using full heat the Ethiopian Yirgacheffe were the darkest of the beans and the Colombian and Brazil around the same colour (light/medium)