Greetings!
I recently installed a La Spaziale Vivaldi S1 V2 and am having fun dialing in the variables. (but burning through a lot of coffee!!)

I am coming from a Livia 90 (that I had running without fail for almost 15 years) and using a Baratza Vario grinder.

I will note that my water pressure is low--20 psi. This is from my RO unit, but have used it for years. However, the flow rate is more than enough for the pump, and I adjusted the output only slightly to be 9bar at brewing.

Anyway, I have been playing with preinfusion, and have been wondering if the objective it to wet the entire puck or to prewet the surface?? (or, for that matter, if it is even a good idea to use it.) For example, if I set at 4 seconds then quickly shut the brewing off before the pump kicks in, it looks like about 60% of the the puck (15gram) is wet.

Pre-infusion help to have a more even extraction of the coffee, but also of the flavor. Try for yourself doing, no preinfusion, 3 sec preinfusion and 5 sec...etc. You should notice some difference in flavor and in body.

As for example, I found that Black Cat actual blend benefit from a 5 sec preinfusion, giving more tobacco and leather note to the coffee.

The time of preinfusion time vary from coffee to coffee, but I found that it gives a more smooth espresso, and can extract some flavor and more complexity.

But it's not necessary to pre-infuse and you can have great tasting espresso without it.

Thanks Marc, I appreciate the advice. I might also look into additional equipment to add to the pressure of my RO unit. The flow rate from the 3/8 inch RO line is fine, but pressure is lower than optimal.

I always found the trick to preinfusion was getting the puck fully saturated prior to the pump kicking in. I believe I was doing around 4-5 seconds at 2-3 bar mains pressure. Now that was a moving target because different coffees would take different infusion times but I had an adjustable delay on make relay so I could make small changes without issue. Everyone will have a different opinion, and that one is mine. I also found preinfusion to be a benefit on some systems and no change on others.

JonF wrote:Greetings!
I recently installed a La Spaziale Vivaldi S1 V2 and am having fun dialing in the variables. (but burning through a lot of coffee!!)

I am coming from a Livia 90 (that I had running without fail for almost 15 years) and using a Baratza Vario grinder.

I will note that my water pressure is low--20 psi. This is from my RO unit, but have used it for years. However, the flow rate is more than enough for the pump, and I adjusted the output only slightly to be 9bar at brewing.

Anyway, I have been playing with preinfusion, and have been wondering if the objective it to wet the entire puck or to prewet the surface?? (or, for that matter, if it is even a good idea to use it.) For example, if I set at 4 seconds then quickly shut the brewing off before the pump kicks in, it looks like about 60% of the the puck (15gram) is wet.

Jim and Ken did some testing of preinfusion a few years ago and I think they found that the effect of preinfusion was largely through better extraction (less puck fracturing). This effect was only present for fully wetted pucks. I could be remembering some of that wrong. In any case, 20 psi is barely more than typical boiler pressure, so I'm not sure that it would be sufficient to fully wet the puck over any reasonable amount of time.

Another argument for moving from your RO source is that depending on your incoming water chemistry, your RO could be acidic, and leaching boiler metals (here is a link that decribes how RO filtration can lower ph http://www.freedrinkingwater.com/water-education2/ro-ph.htm). Even if that is not important to you, RO is widely believed to be a poor choice for good espresso.

You could consider adding a mixing valve to connect the RO filter output and the cold water tap. Or, it would be fairly easy and inexpensive to switch the S1 to a cation softener and carbon filter off the cold water tap.

Mark

cannonfodder wrote:I always found the trick to preinfusion was getting the puck fully saturated prior to the pump kicking in. I believe I was doing around 4-5 seconds at 2-3 bar mains pressure. Now that was a moving target because different coffees would take different infusion times but I had an adjustable delay on make relay so I could make small changes without issue. Everyone will have a different opinion, and that one is mine. I also found preinfusion to be a benefit on some systems and no change on others.

I believe this is also how most lever-users do: preinfuse until the first drops show as a sign of fully wet pucks.

Marc wrote:But it's not necessary to pre-infuse and you can have great tasting espresso without it.

+1.

This has been my experience with the Spaz S1V1. The S1V1 is a worst case scenario: tall narrow 53mm double basket combined with an unforgiving rotary pump. So if any machine "needs" preinfusion, this one is it.

Out of curiosity, I added the aftermarket mechanical preinfusion chamber... and then removed it after a few weeks, because I saw no positive benefit in the taste (or appearance) of my shots. Granted, I had no way to do a careful comparison between P/I and non-P/I shots, so feel free to treat this observation as purely anecdotal.

Nonetheless, an excellent grinder and good puck prep appear to make preinfusion optional. On my gear and IMHO of course.

Thanks all for the suggestions. Living in farming country, I am planning on staying with RO. The incoming water from our very deep well is from a nice aquifer, but is VERY high in mineral (and a few other things I would like to filter out). So we soften it and then go into an RO unit. Actually tastes great, and I have used it for years for espresso via my Livia 90. It seems to have enough mineral to work with the level sensors in both the Livia and the Vivaldi S1 V2. I have not tested pH, but my Livia is going on 15 years, and mainly replaced it to get more consistent shots.

But I would like to increase the pressure to the machine. Looks like a couple options are a booster pump for water going into the RO unit or a demand pump after the RO unit. Not sure which way I am going on this.

For my beans, I seem to be getting better shots and more even pucks with preinfusion off. Luckily, it's easy to experiment . . . I have to remember I had 15 years with my Livia and about 1 week so far with my La Spaziale.

Hoenen wrote:I believe this is also how most lever-users do: preinfuse until the first drops show as a sign of fully wet pucks.

Yes; the drips are not mandatory yet it feels when the puck is wet. Also (at least on La Peppina) others share my experience of having less preinfusion for single basket then double (edit: less active preinfusion movements)

On Caravel I was brewing shots from the middle basket of 10g doses with and without preinfusion; have not been playing with it lately though but as far as I remember it made a difference in taste for some coffees in the richness and, if you compared the experience of espresso shot to a drawing, in the lines thickness I would say.

Anyway this are nuances what we speak...