https://www.bbc.co.uk/news/av/uk-england-hampshire-51357526/portsmouth-academic-develops-perfect-espresso-formula
discuss

If he can conduct a follow up study on why all Americanos from UK coffee shops taste like dish water he could be on for the Nobel prize.

this video goes in to detail. Even if you aren’t fanatical about coffee, I find James Hoffmann’s videos excellent!

FEWER beans.

Even if you aren’t fanatical about coffee, I find James Hoffmann’s videos excellent!

Agreed, though I’m ashamed to confess my initial impression (unfairly based on looks alone!) was not favourable. I find his manner and presenting style very soothing with just a smidge of self mockery.

I really need to listen to the Hoff’s video at home rather than at work. It seems he’s not rubbishing it as an idea, but wants to do more tests to look into it.

Personally I’ll stick to use a fine grind with my 17-19g of beans per shot thanks, hand pressed via the flair I get bloody lovely coffee every time!

FEWER beans

Fewer beans less coffee.

I need a really fine grind for my machine (Gaggia dose) otherwise it comes out like water. I think the flow would need to be restricted some other way.

I need a really fine grind for my machine (Gaggia dose) otherwise it comes out like water. I think the flow would need to be restricted some other way.

From a fluid dynamics point of view, if the bed of coffee is fine enough to cause the majority of the pressure drop you only get the high pressures at the top of the bed, the bottom would be basically atmospheric. I’m not entirely convinced espresso machines work the way some people think they do.

So was the conclusion ,don’t let the bastards grind you it down?

IME it depends on the beans, their roast and their age. And different beans require different grinds and temperature (and the same grinder setting doesn’t always produce the same grind even within a bag of beans)

From a fluid dynamics point of view, if the bed of coffee is fine enough to cause the majority of the pressure drop you only get the high pressures at the top of the bed, the bottom would be basically atmospheric. I’m not entirely convinced espresso machines work the way some people think they do

Indeed, and I think some machines have a small hole after the portafilter which would ensure high pressure throughout the grounds and enable experimentation with this technique.

^ your prob thinking of a pressurised filter basket which you find on cheap machines as an aid for folk who don’t realise the correlation between grind/tamping force/crema extraction, all they do is force the brew through a tiny pin hole to aid in producing a frothy extraction which visualy resembles a genuine crema extraction but bears no resemblance.

Interesting, haven’t had chance to watch the second vid but do they go into extraction time?
I’m grinding 18g, tamping around 30lbs and aiming for 25-30sec extraction. These (IME) should stay constant – the variable is the coarseness of the grind required to get that extraction time.

So, grinding less coffee more coarsely, I either have to tamp harder or accept a short extraction.

Fewer beans less coffee.

Correct, fewer beans.

FEWER beans.

3rd post, excellent work, standards need to be upheld.

your prob thinking of a pressurised filter basket which you find on cheap machines as an aid for folk who don’t realise the correlation between grind/tamping force/crema extraction,

Not entirely.

My old Gaggia baby didn’t, but the newer (more expensive) delonghi does. Also it’s much more accurate in the volume/timing regardless of the coffee you put in there (which implies the remaining variable is pressure).

Which goes back to my point, which is better, the artisanal “proper” way with a pressure drop across the coffee, or a less tamped/coarser bed and the pressure control done downstream.

all they do is force the brew through a tiny pin hole to aid in producing a frothy extraction which visualy resembles a genuine crema extraction but bears no resemblance.

Not entirely true, it still makes crap coffee if you mess up the grinding/tamping step.

The problem with that report is they still used more coffee than espresso is ‘supposed’ to have. Too many places use artisanal coffee that requires 16-20 grams of grounds per double shot to make a decent tasting cup. Find a coffee roaster that makes a roast that tastes good with 7g per shot. Then you are making espresso properly. Plus saving a lot of coffee. Grind and tamp for a 25 second extraction. Job jobbed.

3rd post, excellent work, standards need to be upheld.

Absolutely, this forum is a beacon for everything from screenwash to lubrication for curtain rails, we cannot have its gravitas undermined by schoolboy grammar errors.

it´s gravita´s undermined by schoolboy grammar error´s.

LMFTFY

Funny

@cromo are you talking 7g for a double?

I drink coffee from roasters who make decent light roast coffee, I’m not sure how you think they should do this differently to make 7g stretch to flavour 36g of water? As in I currently use a close to 2:1 water to coffee ratio and that works very well.

I’m intrigued by this 7g too. I’ve never used a roaster who’s recommended less than about 17g; the bars I go to don’t dose so low either.
I drink ristrettos at home anyway, and have never got the hang of the single basket…

Get some decent beans from Europe, half a kilo sent from Berlin less than £3 postage although the beans are a wee bit dearer than that, great service from The Barn

Plenty of nonsense here. 7g is a single shot. 15g is what I and many in the industry have been using for several years.

One of the academics who worked on the paper is Chris Hendon, whom I know. He’s very, very clever and knows a great deal about the chemistry of coffee. The main take home is that you can achieve high extraction yields at lower pressures (peak of 6 bar) with a fairly coarse grind (I’m using 1.8 – 2.5 on my EK 43) and a quick extraction and it is more consistent.

If you don’t understand what this means then you’re probably not qualified to critique the paper, or write nonsense about using 7g baskets.

JP

One other thing – home espresso users get all hung up about tamp pressure. It doesn’t matter (and I’ve tested this when I did a review of the Puqpress, which can be set to tamp at several pressures). All you need is consistency, not the ability to achieve 30lbs of pressure (in fact a light tamp is less likely to create RSI issues when you’re working in a busy shop).

JP

your prob thinking of a pressurised filter basket which you find on cheap machines as an aid for folk who don’t realise the correlation between grind/tamping force/crema extraction

I’d rather it were consistent. I don’t always buy the same coffee, and each different one I get requires me to vary the grind or the amount of coffee I use to get a decent shot.

FEWER beans

But moar pedants!

are you talking 7g for a double?

No, sorry, ijumped back and forth between singles and doubles without really making that obvious. The ‘rules’ for making an espresso, from the national espresso institute in Italy specify:

Necessary portion of ground coffee 7 g ± 0,5
• Exit temperature of water from the unit 88°C ± 2°C
• Temperature of the drink in the cup 67°C ± 3°C
• Entry water pressure 9 bar ± 1
• Percolation time 25 seconds ± 2,5 seconds
• Viscosity at 45°C > 1,5 mPa s
• Total fat > 2 mg/ml
• Caffeine < 100 mg/cup
• Millilitres in the cup (including foam) 25 ml ± 2,5

Or 14g for a 50ml double. If you don’t know this you probably have never had ‘proper espresso.😉 First time I had one was a revelation. Taste nothing like the espresso most places serve. It’s buttery and Rich and nutty and not particularly acidic.

Too many places overdose, which means roasters make roasts and blends that need overdosing, which leads to overdosing which leads to etc. etc. Also a lot of places think fresh coffee is best. Seems like 2 day old or more is better.

@cromolyolly any measure for dissolved coffee solids in that specification?

Did you compare the flavour profile of that on-spec brew with off-spec one from the same beans to see if the main effect was brew method or beans?

the coffee-age discussion is long-running. It seems to be a matter of taste if the various opinions I’ve read are a guide. Same-day beans can produce a very bubbly extraction as the CO2 comes out of the roasted beans into the extract and then out. Older beans have released most of this to the atmosphere.  I generally find very freshly roasted coffee more delicious than older coffee.

These days I’m mostly going for filtered coffee (Kalita wave or Technivorm).

one question for folks: Stir crema in, or leave it on top?

I was curious so for the first time ever I weighed how much coffee in my double 19g , 2 scoops of my plastic spoon but none of this scraping it flush maybe that’s my 3 g extra. Here’s hoping it’s within tolerance
Now my flat white let’s stir up the hornets nest, warmed up mug essential, my double shot, semi skimmed milk 60 to 66°c
I’m waiting to hear from the blue lid aficionados on here wrong temp wrong mulk

What is the viscometer of choice for the discerning espresso drinker? Brookfield?

This whole thing is a vehicle for men to express over-attention to detail, desire for order, the pursuit of authenticity and rectitude and the innate male tendency to want to dominate. Resulting in attempts to find the single clearly defined definition of the only way espresso should be. Just look at the number of times the word ‘proper’ gets used when talking about coffee and how other people’s drinks are dismissed.

By all means learn about it, but drink what you like, roast what you like, brew how you like. There’s no ‘one’ coffee method that is inherently superior.

Or 14g for a 50ml double. If you don’t know this you probably have never had ‘proper espresso.😉 First time I had one was a revelation. Taste nothing like the espresso most places serve. It’s buttery and Rich and nutty and not particularly acidic.

Ignoring the beans the main problem in the UK (and most of France) is the temperature.
Due to the fascination with adding frothy cow juice to poor coffee the UK model of a Italian machine has the temperatures set higher than the same machines in Italy.

In France (and I suspect much of the continent) typically many cafe’s and resto’s don’t own the commercial machines but they are leased from the coffee supplier and the exit temperatures are set according to profiles so a morning coffee shop who will serve frothy cow juice will have a slightly higher temperature than a resto that serves after dinner coffee.
(This was explained to me by my coffee/machine supplier a over a decade ago)

This whole thing is a vehicle for men to express over-attention to detail, desire for order, the pursuit of authenticity and rectitude and the innate male tendency to want to dominate.

Come to Singletrack for the tips on making coffee, stay for the insight into the male psyche….

molgrips

This whole thing is a vehicle for men to express over-attention to detail, desire for order, the pursuit of authenticity and rectitude and the innate male tendency to want to dominate.

I think we’ve just witnessed peak STW.

Excellent insight but stop being such a fun sponge, Drac Molgrips 🙂

I used to home roast, and always preferred brewing with 1+ week old beans, but often had to use same day roasts when I ran out. There was definitely a difference.

@stumpy01 as long as we are all agreed on a number 1 spindle, I’m happy!

Matt

If he can conduct a follow up study on why all Americanos from UK coffee shops taste like dish water he could be on for the Nobel prize.

Because an americano is a silly drink – an espresso topped up with water! What else do you expect it to taste of? If I want a large coffee, I’d rather have a filter coffee, which when both are offered is usually cheaper. Visit Wheelcraft to learn more about filter coffee.

I’d like to read about the details of coffee brewing, it’s interesting, I just wish we could do it without the passive-aggression*. It’s such a shame.

* and yes I know I was joining in

Did you compare the flavour profile of that on-spec brew with off-spec one from the same beans to see if the main effect was brew method or beans?

Me, no because the barista wouldn’t serve one off spec. I have had underextracted brews and over extracted brews and like most people I found them thin, sour and bitter respectively

I would think that the viscosity is a related indicator of dissolved solids.