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Making espresso with ultrasound

unsw.edu.au

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Re: Making espresso with ultrasound

#51

Post by nickff »

jurf wrote: post #42

> Both espresso samples were served at 22 °C to ensure a fair like-for-like comparison […] > It is noted that espresso is normally consumed hot and has transient sensory attributes that are temperature- and time-dependent. Hence, serving espresso at 22 °C will alter its sensory characteristics. This is a weird test, coffee get’s so much worse when cold. So people can’t distinguish between two bad coffees.

"Good" (well-extracted) coffee is still relatively good when warm, especially compared to "bad" (over-extracted, or under-extracted) coffee. That said, many believe that the optimal temperature for serving coffee is 50-60 degrees celsius (122-140 degrees fahrenheit).

Re: Making espresso with ultrasound

#53

Post by ceejayoz »

supertroop wrote: post #52

This sounds awful. I’m an espresso snob and caffeine isn’t even on my list of why I love it. It’s like they complete ignored what makes a good shot and focused on one element.

> “And when we gave our ultrasonic espresso to 100 regular coffee drinkers in a randomised test, they could not tell it apart from a normal espresso.”

I like the ritual of it, for sure, but I'm not sure that's what makes it a good shot?

Re: Making espresso with ultrasound

#54

Post by supertroop »

ceejayoz wrote: post #53
supertroop wrote: post #52

This sounds awful. I’m an espresso snob and caffeine isn’t even on my list of why I love it. It’s like they complete ignored what makes a good shot and focused on one element.

> “And when we gave our ultrasonic espresso to 100 regular coffee drinkers in a randomised test, they could not tell it apart from a normal espresso.” I like the ritual of it, for sure, but I'm not sure that's what makes it a good shot ?

Regular coffee drinkers vs snobs are two vastly different categories. In the guy that ruins your fun. ;)

Re: Making espresso with ultrasound

#55

Post by slwvx »

supertroop wrote: post #54
ceejayoz wrote: post #53

Earlier quoted context omitted.

> “And when we gave our ultrasonic espresso to 100 regular coffee drinkers in a randomised test, they could not tell it apart from a normal espresso.” I like the ritual of it, for sure, but I'm not sure that's what makes it a good shot ?

Regular coffee drinkers vs snobs are two vastly different categories. In the guy that ruins your fun. ;)

I grow my own beans and harvest rain water from my roof to use in my coffee ritual and ... am happy to let others do their own thing

Re: Making espresso with ultrasound

#56

Post by emptybits »

Of all the objective and subjective metrics a home coffee drinker is trying to optimize, never once have I heard anyone care in the least about the watt-hours consumed during the brew process. "I really wish I could drink coffee at room temperature all the time and save a penny on electricity while doing it!" Someone will do the math, I'm sure it's not exactly a penny.

TL;DR: Aiming for a high-volume industrial goal, tone-deaf to coffee enthusiasts.

Re: Making espresso with ultrasound

#57

Post by cush »

supertroop wrote: post #52

This sounds awful. I’m an espresso snob and caffeine isn’t even on my list of why I love it. It’s like they complete ignored what makes a good shot and focused on one element.

I'm curious why you focused on caffeine when the article says their study found that people tasted no difference

Re: Making espresso with ultrasound

#58

Post by econ »

emptybits wrote: post #56

Of all the objective and subjective metrics a home coffee drinker is trying to optimize, never once have I heard anyone care in the least about the watt-hours consumed during the brew process. "I really wish I could drink coffee at room temperature all the time and save a penny on electricity while doing it!" Someone will do the math, I'm sure it's not exactly a penny. TL;DR: Aiming for a high-volume industrial goal,…

Actually, heating and pressurizing is limited by how much juice your electrical installation can pour out.

Re: Making espresso with ultrasound

#59

Post by hylaride »

jurf wrote: post #42

> Both espresso samples were served at 22 °C to ensure a fair like-for-like comparison […] > It is noted that espresso is normally consumed hot and has transient sensory attributes that are temperature- and time-dependent. Hence, serving espresso at 22 °C will alter its sensory characteristics. This is a weird test, coffee get’s so much worse when cold. So people can’t distinguish between two bad coffees.

> coffee get’s so much worse when cold

Coldbrew is a thing and done right it brings out a refreshing sweetness. Also iced coffee. Bad coffee is bad hot or cold.

Re: Making espresso with ultrasound

#60

Post by cush »

This is really cool, I have so many questions! What's interesting to me is they only replaced the hot water part of the equation, and the system still requires high pressure.

How does ultrasound affect flow rate? Do fines sink to the bottom of the puck and choke the shot?

There is a new movement happening, especially in lighter roast coffees, where we're finding that more balanced extractions (less bitterness/acidity/acridity) are happening at lower pressures, even going so far as grinding so coarse that the puck offers zero resistance - effectively making the pump the limiting factor for flow rate. Light roast coffee is much less porous and more hydrophobic.

I wonder if adding ultrasound would allow light roasts to yield more extraction in general, maybe even keeping the high temperature. Or, would adding ultrasound allow a finer grind size and more resistance without adding the harsh flavors of a high-temperature shot.

So many experiments to be done!

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