Correct dose

[qpsport]

I am confused regarding correct dose weight for producing the elusive "God Shot". The INEI ("The Italian Espresso National Institute safeguards and promotes the original Espresso through a product certification: the Certified Italian Espresso") stipulates 7 g +/- 0.5 Elsewhere I have read that at least on home machines, it is very difficult to pull a good shot using a single cup basket, and you should use a double basket. This requires a much larger dose weight e.g. 16-18 g. Obviously the proof is in the tasting, and I prefer the larger amount of coffee. I have never seen a double basket used in any of the espresso shops I have visited. Is that because commercial machines are that much better at extraction than my home Giotto? Or is the smaller amount simply a way to maximize the quality while minimizing amount of coffee used, i.e. cheaper than double the amount? Or do the "arbiters" at INEI prefer a different taste profile to those suggesting the double basket?

[aindfan]

I have never seen a double basket used in any of the espresso shops I have visited.

Have you enjoyed the espresso that you had there? Can you ask for a double shot to compare the taste?

A lot (most/all) of the great cafes that I have been to (who keep quality high enough for me to return) either don't offer single shots (because their beans use one specific dose requiring a double/triple basket) or split a double shot into two cups, hoping that someone else orders another drink requiring the second half of the shot (as it otherwise goes down the drain).

Generally I start with the suggestions given by a roaster for the optimal espresso dose. The 7+/-.5 is an average sort of single shot starting point, and most blends in US seem to require 14-21g for a 1-2oz shot (note the great variance across those ranges).

As you have correctly observed, what tastes best to you is what you should be pulling, so no need to make shots at a dose someone else said to use if you don't like it.

[cafeIKE]

Dose 'weight' per se has almost no bearing on the probability of pulling a G-shot.

Singles are not more difficult to pull, assuming one crosses all the i's and dots all the t's.
Doubles are easier for the sloppy because a 1g error on 16g is less percentage error than on 7g.

BTW, are you sure the shops are not using a double basket in a single spout PF?

[another_jim]

I am confused regarding correct dose weight for producing the elusive "God Shot".

Short answer: different coffees are best at different doses.

Medium answer: Take a basket and fill it a little, say a double basket with 12 grams. Then you need to grind very fine to get the shot to flow at the right pace. Because you grind fine, you extract a lot of solubles from the puck. Take the same basket and fill it a lot, say a double basket at 18 grams. Then you need to grind coarsely to get the right flow, and you extract fewer solubles from the coffee. Acidic and sugary flavors extract fast, and will be in both shots. Caramel, chocolate and smoky flavors extract more slowly and will be more apparent in the low dose shot.

Long answer

[malachi]

There is no universal "correct" dose and in fact many would argue that the concept of "correct" dose (regardless of lack of universality) is in an of itself somewhere between problematic and just wrong.

[Psyd]

many would argue that the concept of "correct" dose is in an of itself somewhere between problematic and just wrong.

With the possible exception of that term being applied to "the dose that I use to make this bean or blend act the way that I want it to".

If you find a dose that always performs as expected, and as you prefer, for a specific coffee, then that is the 'correct' dose for you.

Other than that, anything that can be ground to pull in around (or nearabouts) half a minute and will still fit in the basket, when locked in, could be described as potentially correct.

[cannonfodder]

You cannot produce a God shot. They just happen, which is why it is called a God shot. Despite your best efforts you cannot intentionally pull a god shot. Now and then a good shot miraculously becomes a god shot. Now here is a caveat. The better you get at pulling shots the more consistent you will get. Good will become better and better will become best. God shots become few and very far between because your standards have risen.

[AndyS]

Take a basket and fill it a little, say a double basket with 12 grams. Then you need to grind very fine to get the shot to flow at the right pace. Because you grind fine, you extract a lot of solubles from the puck. Take the same basket and fill it a lot, say a double basket at 18 grams. Then you need to grind coarsely to get the right flow, and you extract fewer solubles from the coffee.

For some time, I too, have believed the same theory: solubles yield is more or less inversely proportional to dose. It stands to reason that low doses, more finely ground, would yield higher. But I'm having a great deal of difficulty proving the theory with actual measurements.

For instance, today I did a series of shots using 49th Parallel's Epic Espresso Blend. I started with 18g doses, yielding 29g of beverage. This is a fairly typical espresso brew ratio of 18/29, or 62%. The solubles yield numbers were running about 18.5%

Then I pulled a series of shots using 14g doses. To maintain approximately the same shot timing, this required a grind three clicks finer on a new Anfim Super Caimano. But the results confounded my expectations.

With the 14g doses, maintaining about the same brew ratio, my measured solubles yield went DOWN 1.5% to 2%. To get back to the 18.5% solubles yield range, I had to pull "longer" shots (brew ratio ~54%, 26g of beverage). [see chart, below]

Notes:
(1) I'm measuring solubles yield (not solids yield) with a Terroir espresso refractometer.
(2) FWIW, the shots that tasted best balanced to me were 14g doses, ~22g beverage, ~54% brew ratio.

[another_jim]

I had a very strong inverse relation on the M3 and the Mini, and much less of a slope, but still inverse ones with the conicals (the graphs are somewhere on the TGP thread). I figured since the taste variability was less too, the flatter yield curve was what made the conicals so much less screwup prone.

Your results make no sense to me. If they are true, the lower dose shots should taste more extreme, and the higher does ones more rounded, on the Caimano. If that part is true, then it's some real oddity in the burr design. But if the high/low dose taste relation remains the same, then my theory is screwed; since it means the taste changes on dosing have nothing to do with the extraction changes.

I'm not hugely wedded to my espresso extraction theory. But still, I'm not going to give up on it until I see a lot more counter evidence than that.

[zin1953]

I am confused regarding correct dose weight for producing the elusive "God Shot".

If it was as simple as "correct dose" = "God Shot", we'd all be praying at the Altar of Digital Scale . . .

In reality, however, god shots remain an elusive phenomenon.

The INEI ("The Italian Espresso National Institute safeguards and promotes the original Espresso through a product certification: the Certified Italian Espresso") stipulates 7 g +/- 0.5

No offense to the INEI, but who cares? It's what's in the cup that counts! Thus, whether or not the INEI approves of what you do in your kitchen is irrelevant . . . unless, of course, you were hoping to put one of their "INEI Approved -- Certified Italian Espresso" stickers on your kitchen window.

Elsewhere I have read that at least on home machines, it is very difficult to pull a good shot using a single cup basket, and you should use a double basket.

Not true.

This requires a much larger dose weight e.g. 16-18 g.

No it doesn't. You can pull the proverbial "god shot" with 16-18 grams in a double basket, but you can also pull a "god shot" with 14-14.5 grams in a double. Or 8 grams in a single. Or . . . or . . . or . . .

I have never seen a double basket used in any of the espresso shops I have visited.

You don't say where in Canada you live, but EVERY café/coffee house/restaurant I've visited in British Columbia routinely use double baskets. Indeed, all through places in Seattle, the San Francisco Bay Area, Los Angeles, and any place else I can think of off the top of my head routinely pull doubles. As Ian has already suggested, "are you sure the shops are not using a double basket in a single spout PF?"

Is that because commercial machines are that much better at extraction than my home Giotto? Or is the smaller amount simply a way to maximize the quality while minimizing amount of coffee used, i.e. cheaper than double the amount? Or do the "arbiters" at INEI prefer a different taste profile to those suggesting the double basket?

None of the above. And all of the above! Some commercial machines probably ARE "much better at extraction" than your Giotto. Then again, your Giotto is certainly the equal of some, and may even be better than some.

Since most cafés/coffee houses in North America serve doubles routinely (that is, you have to ask for a single), this has nothing to do with being "cheap" about their coffee usage. But, as has already been suggested to you, go to a café you know you like and order two straight espressos -- one single, one double -- and taste them . . .

Finally, as far as the INEI's "taste" is concerned, espresso in Italy is indeed different than espresso here. There are differences in roast, taste, etc. If you were able to have an INEI Certified straight espresso served to you, and an espresso served to you by the Canadian Barista Champion at the same time, they would no doubt be quite different.

Cheers,
Jason