Hi

I have V2S1 machine for a year now.
Recently, on the last month, something happened and the used coffee (is there a name for it ?) is very wet, and when I knock it, it just spread and not complete.
The coffee taste "drinkable", nothing more.
The beans are fresh for sure. I buy from local roaster, he didn't change anything.
what should I check ?

Chura wrote:Recently, on the last month, something happened and the used coffee (is there a name for it ?)

We call it a "puck."

If you haven't changed the "dose" (the amount) of coffee in the basket, you can try adding more coffee or the only thing I can think off is the 3 way valve is not working the way it should.

I'll try to weight the puck. how much coffee in grams should I use ? I can see people saying 14g, and some 16g (and anything between)

If you use too little grams of coffee (too much "headroom" between the coffee and the shower screen), it can leave a wet/sloppy puck. If 14 grams leaves a wet puck, try 16 grams. I have never owned a V2S1 so I am clueless on the proper dose weight.

I have a Mini Vivaldi. From the posts I've seen on s1cafe.com (you might post over there - lots of experience with your machine)
generally in a stock basket, the Vivaldi's like a 14 to 16 gram dose. I personally prefer 14 but less than 15. But, you have apparently have good success until lately? So, I'm suspecting your grinder. How long are your shots taking? I'm guessing they're pretty fast. It's not unsual on a Vivaldi to take 40 seconds for a good shot. Have you adjusted your grinder? grind finer. Have you cleaned your grinder lately? How old are the burrs? Is this a new coffee for you? Maybe try a coffee you have had success with before.

I have a Vivaldi II S1 and use 14.5g +/- 0.1g doses into a double basket. This often does not leave an impression of the bolt head on the spent puck so I know I have a fair amount of head-space to dose some more coffee but have been liking the taste of CC Big Trouble at this dose.

Recently, I was noticing my pucks were wetter and even had some water on top if I didn't break suction (partially unlock the portafilter) and give some time for the water to absorb. It had been some time since I had changed screens so dropped the set in use and soaked them and the dispersion block in Cafiza. After some scrubbing with a brush, I reassembled the block and the spare set of screens (I like to alternate sets). I replaced the gasket at the same time since it was starting to cause water to leak around the basket and pulled a couple blank shots just with water.

Shots after the cleaning steps produced a noticeably drier puck.

Based on the above experience, I would suggest - at minimum - a few back-flushes with just water or, preferably cleaning the screens/block, back-flushing with Cafiza followed by thorough rinsing, and pulling a sacrificial shot to see if that changes things.

It's because you just pumped water through it....

Sorry, I had to.

Seriously though, I've had all variables remain equal and ended up with dry pucks and wet ones. I just chalk it up to, my machine decided that it was either worth drinking the shot or not and leaving it in the basket!

Some more coffee in the PF did gave better results.
I prefer to avoid weighting my coffee but i'll do that for checking my technique.
Thank you all