Temperature profiling

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jonr
Posts: 610
Joined: 11 years ago

#1: Post by jonr »

Bill's comment brings many questions to mind.
Billc wrote: I don't think you will see temperature profiling for quite some time. I tried it and it is very dependent upon the coffee you use. Supporting this was a nightmare. It is OK for someone who would like to tinker but it is very hard to direct someone to better coffee through temp profiling.

Rancilio came out with it several years ago, I spoke to their engineers then and they were having similar problems but marketing wanted to release it anyway. Now they do not mention it much.
It seems to me that one could spend 20 min, one time, and then get better taste up until you switch coffee. Sounds pretty simple compared to some of the other things that are done.

My local coffee shop allows me to choose from two different coffees. This means that a) both coffees are brewed at the same start temperature and b) they use whatever temperature profile their non-profiling machine produces. I doubt that either of these are optimal.

If Rancilio's machine is not a commercial success, what are the specific reasons? For example, "we can't taste the difference between a rising, flat or falling temp profile"? Too expensive? What profile did most shops end up using?

I understand that the Rancilio Xcelsius simplified things and only allowed a start temp and then a rise or fall by x degrees. That's probably reasonable, although it might under-represent the full capabilities of temp profiling.

My personal experience is that I prefer a falling temperature profile (measured above the coffee). Once I got that profile dialed-in, I've tended to just leave it there, despite minor changes in roast or coffee. Very easy, but I'm sure there is some additional optimization possible.

Moderator note: This discussion originated in Single Group Slayer - A Production Preview. Please see the original post for context.

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shadowfax
Posts: 3545
Joined: 19 years ago

#2: Post by shadowfax »

jonr wrote:My personal experience is that I prefer a falling temperature profile (measured above the coffee). Once I got that dialed-in, I've tended to just leave it there, despite minor changes in roast or coffee. Very easy, but I'm sure there is some additional optimization possible.
It sounds like you've answered your own question in this paragraph. For a coffee shop or most users, shaping and manipulating a temperature profile is an enormous additional burden of complexity (like open-ended pressure profiling) that they will not deal with if they can dial in a coffee to be as good (or nearly as good) using traditional means (grind, dose, brew ratio, boiler temperature).

We've seen this movie before. Synessos and paddle group La Marzoccos are all over the specialty coffee world. Line pressure preinfusion helps an espresso machine be more forgiving, but how do baristas use the machines that have it? For the most part, not at all. So for a crowd of people that don't have time to deal with manual preinfusion, how should temperature profiling be provided to them?

With pressure profiling now and, I expect, temperature profiling as well, I think we need to have a range of 'profiles' that can reasonably work well at all. Then we need a simple understanding of how changing the shape of the profile within the range affects the extraction of the coffee. It needs to be a very simple decision tree that is very easy to manipulate with simple controls, or I don't think it will ever gain traction. I think you see this problem with pressure profiling already, particularly when you use it in an open-ended way like on a Strada EP. People don't understand it, and they default to a 'flat' profile that they could have just gotten on a much cheaper machine.

It sounds like you built a temperature profiling system, and you stopped adjusting it and just settled on a declining temperature profile that you could get with a well-chosen HX espresso machine. The tinkerer's job is to explore the huge space of options and narrow it down to a small number (or just a single one, if possible) for the end user. If you've done this work and you hardly adjust it, why are you surprised that commercial espresso machines aren't rushing to adopt this technology?
Nicholas Lundgaard

jonr (original poster)
Posts: 610
Joined: 11 years ago

#3: Post by jonr (original poster) »

Perhaps I wasn't clear. I find temp profiling both better tasting and as easy to set up as choosing an initial brew temp. I wouldn't want to go back to a temp profile that isn't roughly optimized for the coffee I'm using. I might find a HX machine to match my current profile, but I certainly wouldn't want to replace it every time I switch coffees and need a different profile. 20 min of work and then months of enjoyment works for me. It's automated so there is no effort involved during brew.

So I'm left wondering why "better taste" and "easy" hasn't led to "common".