Greetings!
I saw 2 other rookie PF threads, but was thinking it was proper protocol to start my own since I have a pretty specific question.

Equipment: I moved from the Livia 90 that I had for 15 years to a Vivaldi S1 V2. So far I have been really happy. It's been a nice change. Very very consistent compared to my previous experience.

Grinder is a Baratza Vario.

Based on the advice I found here, my first BPF experience was pretty good. Just not quite perfect. I am using the double basked in the portafilter, and weighing the dose at 15.5 to 16 grams.

I am generally getting good results, and it seems to match the videos as far as how it starts and forms a center stream, but I am having a little problem with spritzing. Just 1 or two very fine streams head off in one direction or another.

Any suggestions specifically to address spritzing? (or in general, of course).

Thanks all.
Jon

You didn't include information on your routine, so it is a little hard to give much advice. However, I have the exact same setup as you. For me, whenever I ran into spritzing issues I worked on distribution. Do you use WDT in your routine? Also, I found that backing off the tamping pressure helped as well. With the Vivaldi, anything over 5-10 pounds of pressure didn't help and sometimes caused problems. Also, making sure the tamp is level. Being just a little off level can cause issues.

Thanks for the help! Regarding routine, I dry the portafilter, grind directly into the portafilter, bump on the pad a couple times and then tamp to 30 lbs using an Espro curved tamper. I will give the WDT a try, and will also try lighter tamps. Are you leveling the coffee to the top of the basket for WDT? When I use my normal dose I am not near the top of the basket even before tamping.

I am not preinfusing at the moment. Wonder if that might help too?

Seems like a lot of play between the tamper and the sides, but would need to custom order a tamper to get a better fit.

Spritzing can only occur when high pressure flow arrives at the orifice, indicating uneven distribution. Work on your distribution. Try a gentle side to side shake after filling the basket, then a light rap or two on the side of the knock-box. Tamp lightly. The need for 30# is a myth.

Clearance around the tamper is desired. I defy anyone to show that a tighter fit has any effect in the cup whatsoever.

JonF wrote: Are you leveling the coffee to the top of the basket for WDT? When I use my normal dose I am not near the top of the basket even before tamping.

I am not preinfusing at the moment. Wonder if that might help too?

Seems like a lot of play between the tamper and the sides, but would need to custom order a tamper to get a better fit.

I don't level off because, like you, my doses are below the line. I dose into the portafilter with the yogurt cup too and then use WDT. I then tap the portafilter down a couple times and then tamp.

I use pre-infusion. I honestly haven't played around with it enough to know if it makes a marked difference.

My tamper is by no means form fitting. There is a gap on mine as well. I agree with Ian that a tight fitting tamper is better than one with a little play.

I found with the Vivaldi that nutating when tamping clears up the spritzers 95% of the time. I haven't tried tamping lighter, but I will. I always use WDT which helps with the spritzers, but it wasn't until I started nutating that I got rid of them all (mostly). Incidentally, I didn't have nearly as much of a problem with my Anita (E61). Also, I installed the preinfusion gizmo which didn't help the channeling too much either.

With the same set-up, I've found a 14g dose -- smaller than what you're pulling -- to work best. I sometimes tilt the pf to distribute the grounds during dosing and I always tap the sides to get everything in the pf and use a nutating tamp to about 30#. I'm curious about a lighter tamp and will try that. When I updose to 15-16g, the same routine still provides sweet shots but there is more shot-to-shot variability in blonding, etc. I'm not using a bottomless pf so can't speak to spritzing per se.

Doses of 14-16g yield the best results on my setup*, across a wide range of coffees. I generally dose about 15g in the double basket, unless there is a good reason not to (notably taste issues and roast aging).

I always use a bottomless portafilter, and never get spritzies. Let's give credit where due: it's hard to beat a large conical burr grinder for ease of use and consistency. But part of this is meticulous puck prep. I weigh my doses, ensure good distribution with a quick WDT stir, occasionally follow up with a light nutation (when the puck surface looks uneven), and then apply a firm level tamp. All this is done in the basket alone, with the portafilter locked in the grouphead until I'm ready to pull the shot. It may sound like a lot of extra effort, but it actually adds just a few seconds to my routine.

Prepping the basket outside the portafilter:
Several advantages for puck prep. Dosing and weighing the basket is simpler, it's easier to get a level tamp, and the portafilter stays heated in the grouphead for all but the few seconds that it takes to drop in the basket. Be sure to remove the spring clip from the portafilter so that the basket drops in and out freely (unless you have somehow obtained a ridgeless 53mm basket, in which case I want your source!).

Tapping:
Never. Tapping before tamping won't hurt anything if your distribution is correct, but tapping after tamping is invariably bad news. Truth be told, I do not see the benefit of tapping under any circumstances.

Nutation:
This is a distribution method that happens to use the tamper, but it is not a tamping method. You should not nutate with any downwards pressure on the tamper. First nutate to distribute the grinds, then tamp to provide a firm level bed for the initial wetting of grinds. Nutation is quick and easy, and a good alternative to the WDT.

Tamping pressure:
Basically a nonissue. You can tamp lightly or firmly, and get a great pour. Just make sure the tamp is level, and be consistent.

Tamper fit:
Ditto. Any reasonably good fit to the basket is fine. Indeed, some play is desirable if you want to nutate.

Bottomless PF:
Essential. With a regular PF, you can detect a complete meltdown. But a regular PF can also cover up a multitude of sins. If you want to correct technical flaws (channeling, spritzies, etc.), you need a bottomless PF.

* S1V1 model without preinfusion, and the thinner dispersion block

Thanks all! A great set of tips. I think nutation has helped. Also just a FYI, I am running at 9bar.
Best Regards,
Jon

RapidCoffee wrote:Doses of 14-16g yield the best results on my setup*, across a wide range of coffees. I generally dose about 15g in the double basket, unless there is a good reason not to (notably taste issues and roast aging).

On mine - S1VII with no preinfusion and thicker dispersion block - I usually start and stay around 14g. My doses depend on the given coffee best spot, for which I hunt. It is mostly between 14 and 15 grams, yet some beans lower then 14 happen; above 15 I go rarely but probably because I mostly drink single origins; above 15.5 I go even less often yet it's possible. For bigger doses I happily use triple basket - 18g, 21g, usually raising temp one degree.
I prepare basket within the portafilter and most often do wdt. Also no tap, but a thump against the counter and firm tamp, curved espro for doubles and flat for singles - in my experience it makes a difference somehow.
I was going with no needle for some time too, but my consistency was lower then, could get a bit spoiled flow while not expecting it.