I am trying to dial in my VBM Jr. This morning, my shots are definitely under extracted. I am using 16 grams in the double portafilter. I reached the double shot in about 15 seconds.

Do I updose to get a slower extraction? Or give the beans a finer grind?

Any thoughts?

At 16 grams, you have already updosed (IMHO); I'd grind finer. Try altering only one variable at a time, in this case the fineness of the grind -- before tweaking something else.

For most Faema-style baskets and an E61, 16 grams is a reasonable starting point. Assuming the coffee is fresh, I agree with Jason: Grind finer. Your profile doesn't mention the grinder, but here's a general tip: Don't pussyfoot around by sneaking up to the correct setting. For example, if the pour time is only 15 seconds, move the grind setting 1-1/2 to 2 notches finer on a Mazzer (each notch is approx. 1/8" or 4mm).

Thanks. The coffee is fresh. I am currently using a La Pavoni Jolly.

Grind finer and decrease dose.

another_jim wrote:Grind finer and decrease dose.

+1 if you're after proper "official" Italian espresso which should be 14gm

(Making an assumption your brew pressure is within range)

If you're "3rd wave" or whatever that means, just find a dose/grind level that gives you a double in ~25 seconds, based on bigger dose needing coarser grind. For your 16gm dose you need to grind finer than currently.

depends on the coffee and your desired extraction / flavour profile.

malachi wrote:depends on the coffee and your desired extraction / flavour profile.

Several posters were providing help on the basics of how to avoid what the OP considers (seemingly correctly) to be under-extraction based on his/her present procedure. Where you go from there is a personal matter, and as we all know there's no right and wrong when it comes to taste, although there are large regional differences in expectations of what an espresso should be.

Yes - and the answer of "grind finer or increase dose" (as a way to address under-extraction) is dependent upon the coffee and the desired extraction / flavour profile.

To expand and clarify... the answer to the original question is "yes". You can, in theory, address under-extraction through either a larger dose or a finer grind (and in fact, through other methods as Jim indicates -- finer grind and lower dose for example). Which of these is optimal (rather than just possible), however, is a different question. It is, however, the only relevant question given that the answer to the plainly stated question ("which is possible") is useless ("yes" is not helpful).

Saying "oh updose" is also not helpful (the same is true of saying "grind finer of course") as this pre-supposes you know the coffee being used and the desired flavour profile and extraction (and potentially the machine and grinder being used). By saying, "grind finer, of course" what you would really be saying is, "on my machine with my coffee and to my taste I would grind finer". But the OP is not you, is not using your machine, and probably isn't using your coffee.