Olympia Cremina Preinfusion Process?
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Due to lack of enlightenment, I did not fully appreciate the pre-infusion step on my Cremina my earlier days with this wonderful hunk of steel. Now I think this is really quite important.
I'm hooked on Red Bird, grind it with my customized Mazzer Major.
For a period of time I'd do a count down of seconds with the lever fully up before entering the extraction phase. Now I've settled on just leaving the lever up until it drips. Once the drips start, my assumption is the puck is saturated. I extract at 9 bars with the Naked dial.
My wife tells me, without fail, when I pull a shot at 8 bars or less. The shot is relatively bitter compared to the smooth flavor we see at 9 bars, regardless of the pre-infusion. (I'm doing this out of process experimentation/validation and also do mine the same way, so there is nothing nefarious going on.)
What do you do for pre-infusion?
I'm hooked on Red Bird, grind it with my customized Mazzer Major.
For a period of time I'd do a count down of seconds with the lever fully up before entering the extraction phase. Now I've settled on just leaving the lever up until it drips. Once the drips start, my assumption is the puck is saturated. I extract at 9 bars with the Naked dial.
My wife tells me, without fail, when I pull a shot at 8 bars or less. The shot is relatively bitter compared to the smooth flavor we see at 9 bars, regardless of the pre-infusion. (I'm doing this out of process experimentation/validation and also do mine the same way, so there is nothing nefarious going on.)
What do you do for pre-infusion?
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For my '64 La Pavoni, I usually just leave the lever up. I find that if I grind coarse enough to have drips in the first 15s, the shot is usually runny/fast.
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I do the 15 second preinfusion raising the lever to the top and then I lightly pump (short distance, slow, light pressure strokes) during that time to gently force the water into the coffee and get to where I can see it at the basket bottom (with a mirror facing the bottomless portafilter) by the end of the 15 seconds. Mine would not drip in the 15 seconds without slightly pushing it. I've never tried to see how long before it drips because I've heard/read that more than a 15 second preinfusion tends to over-extract. I also have my grind adjusted to where I really need to lean into it to get the higher pressure, 30-40 second pull (after preinfusion). This results in good dark-rust colored crema that hardly ever blondes, and a shot with nice flavor.
LMWDP #581 .......... May your roasts, grinds, and pulls be the best!
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I'm new to the Cremina and still experimenting. I've been waiting eight seconds with the lever all the way up and then gentle pressure for about six seconds before applying full pressure. I tried a shorter time at the top but the shot weight dropped a couple of grams. I want to try reducing the initial light pull time, but I'm waiting for a backordered bottomless portafilter to arrive so I can better see and judge what is going on with the extraction.
Rocky
Rocky
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So I'm doing something slightly different. Before I mount the portafilter I do a quick lever up to put hot water into the group head. Initially it's like the cooling flush on a e61 Hx machine. After about 1-2 seconds the steam popping stops and I put the lever down. It seems like this puts more volume in the group head which your light pumps are addressing when I mount the portafilter. I did this because I noticed the lever tension on shot #1 is decidedly lower than for shot #2. This makes the lever tension approximately the same for both shots.Tonefish wrote:I do the 15 second preinfusion raising the lever to the top and then I lightly pump (short distance, slow, light pressure strokes) during that time to gently force the water into the coffee and get to where I can see it at the basket bottom (with a mirror facing the bottomless portafilter) by the end of the 15 seconds. Mine would not drip in the 15 seconds without slightly pushing it. I've never tried to see how long before it drips because I've heard/read that more than a 15 second preinfusion tends to over-extract. I also have my grind adjusted to where I really need to lean into it to get the higher pressure, 30-40 second pull (after preinfusion). This results in good dark-rust colored crema that hardly ever blondes, and a shot with nice flavor.
Then I mount the portafilter with the full basket to start pre-infusion.
Since doing this I notice the same thing - good color in the crema. If I get any blonding, it's the drips after the lever has been fully down for a few seconds. And not surprisingly the same nice flavor.
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Interesting! When you put the lever up are you referring to the half-pumps that you would also do to heat the group, or are you doing full up and gushing water and steam through the shower screen to be sure all of the air is gone?jwCrema wrote:So I'm doing something slightly different. Before I mount the portafilter I do a quick lever up to put hot water into the group head. Initially it's like the cooling flush on a e61 Hx machine. After about 1-2 seconds the steam popping stops and I put the lever down. It seems like this puts more volume in the group head which your light pumps are addressing when I mount the portafilter.
Are you also venting the steam wand first? I forgot to mention that too.
LMWDP #581 .......... May your roasts, grinds, and pulls be the best!
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I bought the new Cremina boiler cap which eliminates false pressure. And I will painfully add, never touch the thing when the machine is in use. Steam is painful.
Full up to gush. But a quick gush - just enough to get the steam popping to quit.
Full up to gush. But a quick gush - just enough to get the steam popping to quit.
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Oh, so it is the steam you are purging and replacing with water? My Cremina cap is the old one that vents the steam until it shuts too, so I guess the steam wand thing is just an old habit.
LMWDP #581 .......... May your roasts, grinds, and pulls be the best!
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The purging of false pressure is a requirement in my view. Exactly, the steam is replaced with water.
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Man, this is all so much to take in! I just got done rebuilding my Cremina, and I've pulled some really amazing shots on it (and some truly awful ones as well!). All these different techniques are interesting, but honestly it's just adding to my confusion!
Single pump or double pump?
Tamp firmly, or just dress up the surface?
grind finer or coarser?
Preinfuse how long? 6s? 15s? until it drips?
yikes! It's all overwhelming. Can anybody give me a 'basic' procedure in as much detail as possible to get started with as a base point? I know trial and error will play a big roll, and I'll develop my own method/style over time, but man is the learning curve steep!
Single pump or double pump?
Tamp firmly, or just dress up the surface?
grind finer or coarser?
Preinfuse how long? 6s? 15s? until it drips?
yikes! It's all overwhelming. Can anybody give me a 'basic' procedure in as much detail as possible to get started with as a base point? I know trial and error will play a big roll, and I'll develop my own method/style over time, but man is the learning curve steep!