Comparison between the core profiles (RTD/Rest)

[nrdlnd]

I’ve tried to make a comparison between the core profiles at different altitudes. First the RTD.

Four_RTD_compare_v1.png.png (69.36 KiB) Viewed 9774 times

From top to bottom: 2000-2700 RTD, 1500-2000 RTD, 1200-1500 RTD, 0-1200 RTD.

The two lowest are almost identical. The only difference is that 1200-1500 RTD has a higher preheat. The higher the altitude the more energy the first 5 minutes.

Four_Rest_Compare.png.png (69.78 KiB) Viewed 9774 times

From top to bottom: 1500-2000 Rest, 2000-2700 Rest, 1200-1500 Rest, 0-1200 Rest

The 0-1200 Rest is very different from the other three. It has a much lower preheat and a more gradual development. The 1500-2000 Rest gets more heat the first 5 min compared to the 2000-2700 Rest. When I compare the profiles RTD/Rest at different altitudes does the Rest variant usually get more energy (the profile is higher) than the RTD variant except at 0-1200m. I don’t publish any pictures of this except one from the exception where I also compare with another profile.

0-1200m RTD v1_Rest_St&DII.png (68.44 KiB) Viewed 9774 times

From top to bottom (except in the beginning): 0-1200 RTD, 0-1200 Rest, Steady&DarkII

I do also publish a fan profile where 0-1200 RTD and Rest has the same but the Steady&DarkII has a higher fan speed:

0-1200m RTD v1_Rest_St&DII_Fan.png (39.9 KiB) Viewed 9774 times

I’m not shure if it’s correct but to achive a DTR between 20-25% as recommended by Scott Rao a darker espressoroast needs a longer and flatter profile. Are 0-1200 Rest and Steady&DarkII better suited for this kind of roast? I have compared 0-1200 RTD and 0-1200 Rest. To achieve a DTR in the recommended interval with some high quality Brazilians I got a much lower ”L” with the RTD than with the Rest. Besides: What is "L"? Isn't it only the end temperature? When I have succeded to dial in the espresso machine they both were nice espressos but the Rest was the safer bet. Both needed a couple of days of rest before brewing. With Stead&DarkII I’ve had good results with blends with 50% Indian Monsooned Malabar. It tasted very good even after more than a weeks rest.
Per

[fnq]

Hi

I don't think i am following you completely but in regards to your question:

I’m not sure if it’s correct but to achive a DTR between 20-25% as recommended by Scott Rao a darker espressoroast needs a longer and flatter profile.



In my experience med dark espresso profiles for me end up with DTRs above that 20-25% window. I rightly or wrongly associate the need for a higher end temperature with a greater development time- so i am now okay with that - having internally tussled with the Rao sentiment previously.. On roasts where they are rising through FC too quickly JUST to deliver a reasonable DTR i find the taste suffers - so a steady but not steep gradient seems to work best.

Now to my taste buds and preferences. I think darker roasts are more forgiving and whilst probably suffering defects and certainly in some of my cases having some baked flavours , they ( the roasts) seem to be mostly enjoyable. I think lighter roasts aiming to bring out nuances and delicate flavours don't tolerate defects quite as well. so maybe I have set my benchmark a little lower for medium to dark roasts- !!!1

In regard to low altitude roasts - i think the profile can only exhibit flavours that are already there - they can't make a mediocre bean special .

[nrdlnd]

I’m not sure if it’s correct but to achive a DTR between 20-25% as recommended by Scott Rao a darker espressoroast needs a longer and flatter profile.

In my experience med dark espresso profiles for me end up with DTRs above that 20-25% window. I rightly or wrongly associate the need for a higher end temperature with a greater development time- so i am now okay with that - having internally tussled with the Rao sentiment previously......
...In regard to low altitude roasts - i think the profile can only exhibit flavours that are already there - they can't make a mediocre bean special .

Thank you for your interesting views - they got me to think around once more! I've looked through my logs and the ones where I've made good comments are very valuable for me.

The two 0-1200m altitude profiles are rather different. The Rest profile is much "slower" and nore stretched compared to the RTD. I made roasts with both profiles and a Brazilian bean of good quality "Fazenda Samambala" altitude 1200m a Yellow Bourbon processed pulped natural. The "RTD" got a DTR of 24% and L=3.9. It tasted excellent after 4 hours and also after 2½ days. It was medium dark. The "Rest" got an L=4.4 and was darker. DTR became 22%. It did also give an excellent espresso and I think at its best already the day after (one of my best ever!) and very good also after 3½ day. This is interesting as the profiles are rather different! I wouldn't say that lower altitude beans are always mediocre and maybe you didn't mean that. You can find speciality beans also from Brazil.

At the end I can't really say why I started to analyze and compare the core profiles. The differences between the RTD profiles seems logical as the higher grown more dense beans get more heat in the beginning of the roast. The Rest profiles don't quite follow that pattern. I'm still confused how to be able to make a darker roast with a not too high DTR with these profiles or if I should give up that goal. Maybe I can accept lighter roast and adapt my brewing technique instead!
Per

[Geronimo]

I'm still confused how to be able to make a darker roast with a not too high DTR with these profiles or if I should give up that goal. Maybe I can accept lighter roast and adapt my brewing technique instead!

Hi

I’ll join you in the queue for confusing with respect to DTR and darker roasts, in particular, used for milk based drinks. Most of my DTR are in the range of about 28 right thru to 35% if using the recommended dark setting in the notes for the rest profiles. The lowest being Brazil Cerrado at 5.0, has a 28% DTR. And a Guatemala Huehue at around 35%. Just touching on second crack.

I’ve yet to get anything that wows me taste wise when using various blends with milk.

Interestingly I had to remove the control points in each of the Rest profiles for better curve following.

Cheers
G

[nrdlnd]

I’ll join you in the queue for confusing with respect to DTR and darker roasts, in particular, used for milk based drinks. Most of my DTR are in the range of about 28 right thru to 35% if using the recommended dark setting in the notes for the rest profiles. The lowest being Brazil Cerrado at 5.0, has a 28% DTR. And a Guatemala Huehue at around 35%. Just touching on second crack.

I’ve yet to get anything that wows me taste wise when using various blends with milk.

Hi G!,
I'm not sure that you must have a high DTR to be able to brew a nice espresso. Maybe if you prefer very dark roasts but some of the profiles can give dark roasts with a DTR in the interval that Scott Rao recommends. In your case you drink your espresso with milk and I thought that was more forgiving and that a lower DTR or lighter roast could give more flavor to a milk drink.

I've gone through my logs and my best pure black espressos are in the interval 20-25% DTR but I've aimed to stay in that interval. Among them there are beans from different altitudes and they are roasted the corresponding core profiles (both RTD and Rest). Among them were Brazilians, natural Ethiopians and a Chinese from Yunnan and some other origins.

I'm beginning to think that the brewing technique is at least as important as different beans and different roasting profiles. There are so many factors affecting the shot quality when you make an espresso! I.e. temperature, presoak, flushing, grind, dose, distribution in the filter, tamping, extraction degree and so on.

I can give an example; Usually you adjust the fineness of the grind if you think it runs too fast or slow to get a given volume. With a very fine grind you get a better extraction but you may stall the flow. Usually you try to grind less fine but another solution to the problem is to reduce the dose in the basket! To get the same concentration of the drink you have to reduce the volume of the drink accordingly. The extraction rate (TDS) is very important for the taste of the espresso. It affects if it's sour sweet or bitter. Maybe a refractometer is necessary to really learn to dial in you espresso! Cupping is a standardized way of evaluating coffee beans. It's much more difficult to standardize espresso brewing because of the many variables.
Per

[Geronimo]

Many thanks for detailed reply.

[Mark]

Interestingly I’ve been watching a few of Tim Wendelboe’s YouTube videos. He now roasts using a Loring … which is closer to a Hot Air Roaster than a Drum roaster.

He states that they don’t really think about first crack, DTR or colour change anymore… just concentrate on profile time and end temperature.

In thesse videos he talks about concept profiles ie: at lot of energy at the beginning then gradually going down… V … not so much in the beginning but a lot in the middle etc.

https://www.youtube.com/watch?v=aCur6NqcyPk&t=2116s

https://www.youtube.com/watch?v=Akqx4fJEJfg&t=3131s


Cheers Mark

[nrdlnd]

Interestingly I’ve been watching a few of Tim Wendelboe’s YouTube videos. He now roasts using a Loring … which is closer to a Hot Air Roaster than a Drum roaster.

He states that they don’t really think about first crack, DTR or colour change anymore… just concentrate on profile time and end temperature.

In thesse videos he talks about concept profiles ie: at lot of energy at the beginning then gradually going down… V … not so much in the beginning but a lot in the middle etc.

https://www.youtube.com/watch?v=aCur6NqcyPk&t=2116s

https://www.youtube.com/watch?v=Akqx4fJEJfg&t=3131s
Cheers Mark

Thank you Mark for these links! Sorry but I have difficulties finding that information in the very long videos but I believe you. Before anything else is proved I will continue to use the published Kaffelogic profiles and I have got good results with them. Today I made a couple of espresso shots with a bio Sumatra Mandeling. It had 6 days rest. I used the 0-1200 Rest even if I think it came from a little higher altitude. I did put L on 5.0 but I had difficulties hearing 1C. When I heard it clearly I started to record DTR but the roast stopped at about 20% so L became 5.0. When I look att the log I think that DTR came earlier and recalculating made it around 25%. Anyway this became a dark roast (Full City?). Today it was dark, juicy and full of body. Of course not floral. I had to grind it very fine so it didn't run too fast. It was nice on it's own but could make a good blend with some Ethiopian or some other brighter bean. So I think it's possible to make good espresso with these profiles and also rather dark. I think it's possible to make good espresso also with lighter roasts but then the brewing technique must be "perfect" and adapted so it becomes balanced. I will work on it and maybe start measuring TDS and see if a certain TDS is "better".
Per

[fnq]

Hi Mark

Thanks for the Tim Wendelboe links ( i haven't had a chance to watch yet). Interesting 'take' on the important parts of a roast .... and to me , in the small KL roaster, makes heaps of sense. With Mr Wendelboe being a advocate of very light roasts, i will be watching closely to see if the darker roasts categories can still fit these models.
thanks again for the links Darryl

[Mark]

With regards to hearing first crack ... I still use this method ...

https://kaffelogic.com/community/viewto ... p=503#p503


Cheers Mark