I’m still trying to understand the different aspects of the roast. One that I haven’t played with yet is the pre-heat temp. I’ve looked at a number of posted roasting recipes and have seen wide range of pre-heat temps. Any learnings would be appreciated.
For me the main deciding factor is batch size. 1lb batches I use a lower PH temp so I don’t scorch the beans. 1kg batches I use almost the max PH temp allowed because there is a lot of bean mass. When you drop 1kg into the drum the temp in the drum temp drops quite a bit. The higher PH is needed to not lose too much heat and a high P during the drying phase is also needed to have enough momentum to bring that 1kg batch to FC in a reasonable time (e.g. around 9 mins is my target).
I’m sure other folks will chime in with their views on why they use different PH temps.
I usually roast in 800g batches, and my defaults for a first time roast of a washed bean is full blast at 310C, for a honey processed or wet-hulled 305C, and for a natural 300C. I follow this up with a 1 minute “soak”, during which time I ramp up the heat in increments to P9 or P8. I find this gives me very good, and (importantly) repeatable roasts. This almost always gets me to yellowing between 4:00 and 4:30, and (depending on what I’m trying to get out of the bean) to 1st crack between 7:30 and 9:00. These are my defaults for a first roast of a new bean, and I adjust from that point, but I find I nearly always stick to those preheat targets. I’ve seen a lot of variation on roast.world for preheat temps, and I know a lot of folks go significantly lower – I just don’t get the consistency I want with lower preheat temps.
1 Like
Thanks for the response. What do you mean by soak? Is it the time from charging to some bean temp?
“(heat) soak” is a method in which when you start with a very high PH temp your initial P setting when you drop the beans is something lower, e.g. P6. This lets the beans “soak” up the hot air in the drum from the pre-heating for about 1 to 1:15 min (some folks may go longer), then you ramp up the P setting to a P8 or P9 to get you thru the drying phase.
I also do this “soak” as well for my 1kg and 1lb roasts. For example, my 1kg batches typically have a PH of 572F and my initial settings on charging the beans are P6/F1/D7 and I leave it there until around the turning point of the BT line (approx 1 to 1:15 mins) then I bump to P9. For my 1.1kg I start with a PH of 590F and same soaking.
Why would one do this? This old thread and this one might help understand this method. There are roasters here who don’t do this and follow Morten Munchow’s method with good success as well (search the forum for mentions of Morten or Munchow and you’ll get quite a few hits, and he has a free course for bullet roasters as mentioned in this thread). It’s a decision choice, there are no right or wrong answers as long as the result in the cup is what you want and like.
Happy Roasting!
3 Likes
Some people warn against very high Pre Heat with honey processed or Natural processed beans because of the extra sugar that is in the bean, they say that the beans can get scorched.
I normally use a high Pre Heat with a soak.
Recently, I bought some beans from Royal and they had a profile for an Aillio Bullet that had a low PH. It was only a 500g roast. I tried Royal’s roast profile and was pleasantly surprised. I was thinking when I was roasting: “no way” But they are Royal and well respected.
So, I guess my advice is to try different things and find roast profiles that you like. At the end of the day, that is the only thing that matters.
I roast a lot of beans and give away a majority of them.
1 Like
This conversation and the varied methods have always been interesting to me. I prefer to go with a lower PH temp and keep P9 through the first 5-6 min of the roast adjusting F settings at first then lowering P setting to keep things smooth. I think I tried a soak once and didn’t notice much of a difference in the cup so I stuck with my usual method.
I roast 775g batches with a PH Temp between 255-265 C* depending on washed vs natural. Gets me to FC around 9min for most batches.
Similar to what other posters have said this approach gives me wonderful consistency across roasts no matter the bean origin. Just small adjustments here and there depending on varietal
1 Like
Thanks.
It’s interesting that everyone has different approaches that inevitably lead to the result they are looking for.