Bezzera Strega vs. Olympia Cremina - Page 9

Need help with equipment usage or want to share your latest discovery?
User avatar
farmroast
Posts: 1623
Joined: 17 years ago

#81: Post by farmroast »

start with a dose/grind that would be slightly on the easy pull side. Then come down to fill and then several very short pumps and you feel the resistance build. Careful not to over do it, then not forcing it too fast starting the pull.
LMWDP #167 "with coffee we create with wine we celebrate"

User avatar
homeburrero
Team HB
Posts: 4863
Joined: 13 years ago

#82: Post by homeburrero »

another_jim wrote:Yes, that's what I thought I was describing. But with the apparently eighty eight different ways of pumping on a lever, I have no clue what I was seeing.
Makes it clear that Jim was not saying he thought the system pressure actually increases. If you analyze the hydraulics, or if you do this pumping and watch the boiler gauge it is clear that the boiler pressure does not get pumped up. It sorta feels like it does on the lever, which I'm guessing has to do with replacing the air above the puck with water and water vapor. I've thought about it a lot, and use a different technique on my pre-M LP than my post-M (the hydraulics are different) but I also have no clue as to exactly what is going on in there.
TomC wrote:it's been a long time since I've watched that Fellini move video, but I thought it was done on a Cremina, which has no spring like the Ponte Vecchio.
In this video from Fellini's Orchestra Rehearsal you can see the namesake for these myriad pre-infusion moves. Is a commercial spring lever (Gaggia?) in a bar, and the barista gives it 3 little lifts before letting the lever up.

Edit: The original URL that I posted had trouble, and I fixed it with Jon's URL (from his post below.) If you are a Fellini fan and want to see it surrounded with a bit more of his movie, I'm hoping this URL will work reliably : http://www.youtube.com/watch?v=xuiXwOOk ... ature=plcp The pull happens at about 2:43.
Pat
nínádiishʼnahgo gohwééh náshdlį́į́h

User avatar
TomC
Team HB
Posts: 10534
Joined: 13 years ago

#83: Post by TomC »

No video.
Join us and support Artisan Roasting Software=https://artisan-scope.org/donate/

summer
Posts: 183
Joined: 12 years ago

#84: Post by summer »


User avatar
TomC
Team HB
Posts: 10534
Joined: 13 years ago

#85: Post by TomC »

That link works. According to the comments on the video, it's the one other's have referred to in the past. I was thinking earlier posters were referring to an early HB home video of how to pull shots on the Cremina that has been around for a long time.
Join us and support Artisan Roasting Software=https://artisan-scope.org/donate/

User avatar
homeburrero
Team HB
Posts: 4863
Joined: 13 years ago

#86: Post by homeburrero »

Thanks, Jon - yes that's a shorter (and working) snip of the same movie. I'll go edit/fix my post.
Pat
nínádiishʼnahgo gohwééh náshdlį́į́h

User avatar
GVDub
Supporter ♡
Posts: 519
Joined: 15 years ago

#87: Post by GVDub »

The reason it feels like pressure building is that air compresses and water doesn't, so the less spongy feel of air is replaced by the solid feel of water. Or such is my theory.
"Experience is a comb nature gives us after we are bald."
Chinese Proverb
LMWDP#238

User avatar
drgary
Team HB
Posts: 14345
Joined: 14 years ago

#88: Post by drgary »

homeburrero wrote:Is a commercial spring lever (Gaggia?) in a bar, and the barista gives it 3 little lifts before letting the lever up.
Slightly OT but with the knobby handles and the lever attachment on the side of the group that looks like a 1950 to 1953 Gaggia Internazionale commercial lever. There's a thread on CoffeeGeek where someone's restoring a three group version. We see the barista make his multiple pulls for one shot. First there's a pre-infusion, then he pumps again briefly before letting the shot run. He probably would settle on those particular pulls to dial in flow and volume for that coffee, dose and grind.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

User avatar
michaelbenis
Posts: 1517
Joined: 15 years ago

#89: Post by michaelbenis »

A few hopefully helpful comments:

More than one Italian barista "of a certain age" commenting on the so-called Fellini move has said that in the golden age of levers it's what they used to do when a lever group was performing poorly and needed maintenance, either because of problems with the piston seals or spring itself. This squares with one of the groups being out of commission on the machine seen in the clip. Multiple pulls on commercial machines were I am told neither recommended by manufacturers or considered to deliver any consistent benefits worthy of the fuss in the busy environments where these professional baristas worked (and with the coffees they used).

The pumping up Jim refers to regarding the Cremina has nothing to do with increasing the boiler pressure, but with using the piston (either manually or through spring pressure) to increase the preinfusion pressure above boiler pressure up to and for as long as the expanding puck resists flow (each "pumping up" stroke will be in the order of several bar compared with the generally less than one bar tank pressure). In addition, as I understand it, doing this increases shot volume and - if shot time is constant or increased - the length of time for which the coffee grounds are subjected to higher extraction pressures.

There are however lots of variables in play, including needing to grind finer and/or increase the dose or tamping pressure to successfully apply this higher pressure "pump" during preinfusion without the coffee starting to simply drip through. And of course you can turn this around - it's a technique for using the Cremina with finely-ground/high-dosed shots.

Also the potential increase in total infusion time and higher pressure preinfusion certainly blur the lines of where preinfusion ends and infusion starts, but one way or another this technique can offer useful fine-tuning of what happens in the cup and is comparable in some ways to what happens when you leave the Strega pump to ramp up the preinfusion pressure before releasing the lever. Certainly Jim finds it means the two machines can yield similar results.

I hope that helps clarify a little without coming across as wanting to teach anyone how to suck eggs.

Cheers

Mike
LMWDP No. 237

User avatar
cannonfodder
Team HB
Posts: 10497
Joined: 19 years ago

#90: Post by cannonfodder »

I never got the reason for multiple lever pulls. Every lever machine I have used with the exception of one which used a heat exchanger, has a sealed piston. Every time you raise that lever, you suck the puck up out of the basket. You are drawing air up when you raise the lever which will suck any water you pre infused into the puck back up out of the puck. Then while drawing air up through the puck you are either going to suck it completely out of the basket giving you side channeling or cause cracking in the puck or other not very good for your shot issues.

A sealed piston lever machine should be used with one pull. Raise the lever to the point that water flows out of the group then gently lower (or raise) the lever until the flow stops. Then lock your portafilter in place. That will prevent the vacuum action from disrupting your prepared puck. Then with the lever primed to pull your shot, insert your portafilter in the group. Then raise (or lower) the lever to let the boiler water flow into the piston. Hold it for 5-8 seconds to allow the air to be pushed out of the piston and water to pre infuse the puck then pull your shot. You are not pumping up a bike tire, you are making espresso. The Fellini move may be a good idea on broken lever machine but on one in proper working condition, nothing good will come of it. This myth should die just like tapping your portafilter between tamps with your tamper . There is no good reason to do it and many bad reasons not to do it.
Dave Stephens