Nice to see you back, Mr. Barista. Will we be seeing another enjoyable video from you in the near future?

There are so many variables. Lingle counted 24 of them. So a study of one or a few, while potentially illuminating, can be frustrating as well.

With my recent purchase of a Brikka I looked at the effect of brew time (heating rate) and three different grind sizes on the extraction, for just one particular coffee/dose/water. The resulting graph was as one might expect but what tastes good doesn't always cooperate so well.

jpender wrote: There are so many variables. Lingle counted 24 of them. So a study of one or a few, while potentially illuminating, can be frustrating as well.<image>

I'm agree with the first (many variables), but I never felt frustrated . Yes, the topic is far bigger we could cover in an 8 min video. It's just a kick off. It's an amazing one (topic).

Do you have a link to these 24 variables pls?

jpender wrote: With my recent purchase of a Brikka I looked at the effect of brew time (heating rate) and three different grind sizes on the extraction, for just one particular coffee/dose/water. The resulting graph was as one might expect but what tastes good doesn't always cooperate so well.
<image>

It would be interesting to study the effect of the heat intensity (flame height) to Temp profiles and to the taste of the brew.

New video? Thanks for your question. We released it two weeks ago. Search for "espresso voyeurism". I hope you will rate it as enjoyable. The third one is coming soon (hopefully in November).

Cheers

Gabor

naked-portfilter wrote:Do you have a link to these 24 variables pls?

I don't. I read it in the SCAA Coffee Brewing Handbook. I'm sure you could come up with a list on your own but I typed in the headings from Ted Lingle's list below. If you're focused on one part of the process you'll quickly see that even his list is oversimplified.


Blend of components:
1. Ratio of blend components
2. Bulk density of beans
3. Chemical composition of beans

Roast Development:
4. Method of roasting
5. Rate of roasting
6. Degree of roast
7. Rate of degassing

Grind:
8. Average size of particles
9. Size distribution of particles
10 Particle shape

Time of Brewing:
11. Time of water contact

Temperature:
12. Contact temperature
13. Temperature gradient during brewing

Turbulence:
14. Complete wetting
15. Uniform flow
16. Particle movement

Filtering Method:
17. Method of seperation
18. Degree of clarification

Holding Conditions:
19. Length of time and method of holding
20. Holding temperature

Brewing Formula:
21. Coffee (by weight)
22. Water (by volume)

Water:
23. Water composition
24. Water treatment

I finally found your new video. It took me a bit to realize the title isn't espresso voyeurism, it's "Naked". I suppose if you'd told me to search on the latter term the google results might have looked a bit different.

Nice work, by the way. Beautiful cinematography.

Hi John,

thanks for the list and the feed back about Naked. "Espresso voyeurism" is the title (key word) of an article (written in the dailycoffeenews.com) about the Naked .

Cheers

Gábor

Hi,
thanks for the really interesting video! I bought a Brikka 4 cups and a Hario Skerton but I cannot get a decent result when brewing my coffee (too light, too burned...). Could you suggest me, or who may know, a correct grind size (I'm trying 3, 4 and 5 notches on the Skerton) and a right amount of coffe (I'm using between 24 and 30 grams) to use? Thank you very much!
Don

Hi Don,

I use/d the two cup version Brikka with the Hario Mini Mill (6 notches from 0). I prefer the smaller moka pots over bigger ones. I think they produce a tastier brew. But I haven't experimented a lot with the 4 cup model. Maybe I just haven't met the sweet point of it.

Cheers

Gábor

Great video, and amazing setup of an experiment.

Just to compare what looks like 2 methods done in this thread, I think the major variance in the curves could be explained in TC type. The probe in the video looks to have very little mass, and likely will read the correct temp very quickly. As it looked like in the first curve, you could at least delay that exposure to the hot water for a short period of time.

jpender, maybe you're probes have a bit more mass to them, so it takes them longer to respond? However it does look like from your graphs that the coffee stays under 100C for several minutes. It could be a combination of TC type, mass of any shield, and placement.

EspressoForge wrote:jpender, maybe you're probes have a bit more mass to them, so it takes them longer to respond? However it does look like from your graphs that the coffee stays under 100C for several minutes. It could be a combination of TC type, mass of any shield, and placement.

The thermistors I've been using are small (2-3mm), glass or epoxy encapsulated, bead type. I coat them with a thin layer of food safe epoxy to waterproof them and that probably worsens their response time a little. But for this application I don't think it's an issue. When I've measured the response time in water the probes have reported 63% of the change (1-1/e) in under one second and 95% in about 2-3 seconds. For a moka brew that takes several minutes to ramp up a few tens of degrees the error due to response time lag is small.

With regard to placement, there is a vertical temperature gradient across the coffee puck. But the gradient narrows as the brew progresses. So for determining the maximum temperature precise placement doesn't matter nearly as much.

Here's what one of the thermistors I've used looks like, painted with JB Weld. The actual sensor inside is about the size of FDR's ear.

Cheers.