timo888 wrote:Again, the second half of a pump machine's extraction (if it is dosed moderately) will be duller and thinner than the first half's product. (Or do you disagree?)

Agreed. While I haven't compared them closely side-by-side, the second pull of a lever espresso reminds me of the taste of the last third of a pump extraction. In other words, the first and second stroke are reminiscent of the first half and last third of a pump extraction. If you want to get more precise, I recommend Andy's EvaluSpromatic:


Schecter EvaluSpromatic; photo courtesy Mark Prince (flickr)

At some point after the holidays I'll give this a try.

timo888 wrote:This is not a feature peculiar to the lever machine

I disagree. As Steve shows, a pressure profile with a "valley" in the middle is indeed unique to multi-pull levers:

I understand Greg can program his Linea to produce this pressure profile; it would be interesting to see how it affects the extraction, though technically they're not the same since the lever produces negative pressure on the upstroke and his setup cannot.

timo888 wrote:You only get a fracture on the upstroke when you have tamped so hard that you truly have a "puck" rather than a deformable medium.

One can argue that the "brew pressure valley" has minimal negative effects, but judging from the split espresso's appearance, taste, and mouthfeel, it's hard to argue that it's a benefit.




This discussion has been split from Lever Espresso Machines Smackdown by the moderator...

Timo is correct in noting that the character of the espresso changes over the life of the extraction. This is obvious.

John's photos of the two demitasses are a nice attempt, but they clearly over-emphasize his point. The first one in each case was a full extraction, the second was just the remnants. Were both pulls completed within a reasonable time frame? Was there enough of a dose to give a 50% brew ratio to that much water? If you run a pump shot for 60 sec., 30 into each glass, without enough coffee, the results would look similar.

The pertinent question relating to two pulls on a lever machine is whether one can increase the volume of liquid within the confines of a proper extraction, i.e. within an acceptable amount of time, and with a great enough dose to prevent overextration.

PC

After a week off from the Lusso, I pulled a bunch this morning using PT's Coffee La Bella Vita. They were very enjoyable, in fact some of the best espressos of the week, including all those I sampled yesterday at Counter Culture's espresso lab.

peacecup wrote:The pertinent question relating to two pulls on a lever machine is whether one can increase the volume of liquid within the confines of a proper extraction, i.e. within an acceptable amount of time, and with a great enough dose to prevent overextration.

I would pose the question more pragmatically: Will a small volume displacement lever machine like the Ponte Vecchio Lusso and Export produce a better single espresso in one pull or a better double espresso in more than one pull? My guess is that the single espressos will be better because the extraction isn't disrupted by a "brew pressure valley."

peacecup wrote: Were both pulls completed within a reasonable time frame? Was there enough of a dose to give a 50% brew ratio to that much water? If you run a pump shot for 60 sec., 30 into each glass, without enough coffee, the results would look similar.

The pertinent question relating to two pulls on a lever machine is whether one can increase the volume of liquid within the confines of a proper extraction, i.e. within an acceptable amount of time, and with a great enough dose to prevent overextration.

PC

I pull singles, I pull doubles. Both are good on levers, they just require different techniques to taste right.
Peacecup already knows the answer to his question from personal use of levers. Yes it is possible to increase the volume within the proper time and a large enough dose. Is it easy? No, not at first! Given experience and time to learn the machines ins and outs doubles become second nature.

I have done something similar to what John did with his two cups, but my outcomes have usually been a bit harder to tell. Possible, but harder. Again this is something that will come with time and practice, like so much in espresso.

timo888 wrote:This is not a feature peculiar to the lever machine. If you tamp very lightly, the upstroke on the second pull does not fracture the puck and create great rifts for the water to flow through, yielding "dishwater". You only get a fracture on the upstroke when you have tamped so hard that you truly have a "puck" rather than a deformable medium.

I include this because it seems that every time timo has mentioned this, he has been ignored on this point. I fully agree with him that to be able to get a good extraction for a double one must tamp LIGHTLY. From the extractions and the pre extraction pucks that were posted it seems that a light tamp has NOT been tried or perhaps just not posted by the reviewers.

The light tamp that timo is refering to is so light that many would not even consider it a tamp. It is simply using the tamper to flatten the puck enough to lock it in. Give it a try especially with the spring levers and it may open up the realm of good doubles. I also find it to help with manuals though, when grind is quite fine.

I have never bothered to do this test because I have been pretty confident that the second pull with the Ponte Vecchio double basket DOES NOT terribly degrade the espresso. But since John gave it a try with the Pavoni, I thought I'd have a go. Here is my first attempt, done between changing and burping a one-month old, and calming the temper of a four-year old. It was ground slightly too coarsely, and I was too distracted for a Fellini pull. Still the results don't quite agree with John's:



I won't insult your intelligence by asking which is the first pull. But both were good, and had different profiles. The first pull was a cooler temperature, had less volume (perhaps because no Fellini), and had more texture. The second was more flavorful, with that "clarity".

Dan wrote:I would pose the question more pragmatically: Will a small volume displacement lever machine like the Ponte Vecchio Lusso and Export produce a better single espresso in one pull or a better double espresso in more than one pull? My guess is that the single espressos will be better because the extraction isn't disrupted by a "brew pressure valley."

May people seem to prefer singles regardless. The case with the PV is that you get ~15 ml per pull. With the single basket and 7.5g, you can get a great 50% brew ratio single. With the double basket you can get a 50% "double" if you put ~10g in the double basket, because you'll get ~20ml because of the increased volume due to more headspace. Of course you can go for greater brew ratios with the double basket, and these can be very tasty.

If we confine ourselves to discussing the quality of the espresso at a 50% brew ratio, one MUST take more than one pull on the PV if one wants to dose more than ~10g. I've been doing this 3-4 times a day for two years, so I will humbly claim to have a little more experience with this than any of the reviewers. I maintain that one can get good (great) 50% shots using a 15g dose and multiple pulls. I personally did not find it difficult to develop my technique.

If one prefers to limit their espresso from the PV to either small shots or higher brew ratios than a single pull is all that is needed. I believe this will limit the user to what amounts to the first half of an espresso (if one doses >~10g). I do not think that a mulptiple-pull shot will necessarily be overextracted. I'm not convinced that a "pressure valley" is a bad thing - some say that the variable pressure of a lever partly explains the "je ne sais quois' about them. Who is to say a second "valley" won't make it just that much better?

PC

timo888 wrote:If you tamp very lightly, the upstroke on the second pull does not fracture the puck and create great rifts for the water to flow through, yielding "dishwater". You only get a fracture on the upstroke when you have tamped so hard that you truly have a "puck" rather than a deformable medium.

It would be nice to see some evidence supporting this claim. Quite frankly, I don't buy it. I think several other factors come into play, including dose, preinfusion, and machine-specific flow characteristics.

peacecup wrote:Johns photos of the two demitasses are a nice attempt, but they clearly over-emphaize his point. The first one in each case was a full extraction, the second was just the remants. Were both pulls completed within a reasonable time frame? Was there enough of a dose to give a 50% brew ratio to that much water? If you run a pump shot for 60 sec., 30 into each glass, without enough coffee, the results would look similar.

The pertinent question relating to two pulls on a lever machine is whether one can increase the volume of liquid within the confines of a proper extraction, i.e. within an acceptable amount of time, and with a great enough dose to prevent overextration.

Sigh. I suppose I should have weighed the coffee dose and pull volumes, and computed the brew ratios. But I can make some educated guesses. In the first pix, the first pull had a slightly higher brew ratio than 50%, because I used a short preinfusion, and segued directly from the first pull into the second, stopping only to swap cups. In the second pix, the first pull was in the ristretto range (brew ratio over 60%). In both cases, the first pull tasted good but second pull was purely a sink shot.

So there are two reasons why multiple pulls should be viewed with caution: potential for fracturing the puck, and (at least on a high volume displacement lever machine) overextraction.

RapidCoffee wrote:It would be nice to see some evidence supporting this claim. Quite frankly, I don't buy it. I think several other factors come into play, including dose, preinfusion, and machine-specific flow characteristics.

You don't have to buy it, to try it. Other factors always come into play in espresso. Just because you don't believe it will help is not a good reason to avoid trying it. The reviewers are supposed to be experimenting with these machines, correct? Well here is one thing you can try, and perhaps even SEE some supporting evidence first hand. True, it may not work for you, but in the interest of espresso science it should be attempted.

Kaffee Bitte wrote:You don't have to buy it, to try it. Other factors always come into play in espresso. Just because you don't believe it will help is not a good reason to avoid trying it. The reviewers are supposed to be experimenting with these machines, correct? Well here is one thing you can try, and perhaps even SEE some supporting evidence first hand. True, it may not work for you, but in the interest of espresso science it should be atempted.

Oh, I will (try tamping lighter with multiple pulls). But remember, I'm not the one making any claims. What evidence supports the "light tamp => multiple pulls won't fracture the puck" hypothesis? And just to play devil's advocate, why wouldn't a firmer surface (from a harder tamp) resist fracturing to a greater extent on multiple pulls?

Kaffee Bitte wrote:The reviewers are supposed to be experimenting with these machines, correct?

Hi! You must be new to Home-Barista.com, let me introduce myself! My name is Dan, and I've been writing reviews for this site for a few years now. You can read them The Bench. It's our goal that they be both comprehensive and helpful. I tell you, it's not easy to create a readable, helpful, succinct review, but we try!

OK, seriously this time...

It's the weekend, isn't everyone supposed to be relaxing? Please keep the suggestions coming, they will be acted upon in due course.

RapidCoffee wrote:And just to play devil's advocate, why wouldn't a firmer surface (from a harder tamp) resist fracturing to a greater extent on multiple pulls?

It probably would if the piston wasn't creating a vacuum for the second pull. The Gaggia Achille's design avoids this with its double-action pump. The levers in the Smackdown don't have a release, hence the risk of puck damage on the upstroke.

Dan and John, I apologize if my tone seemed rude. It just seemed that timo's suggestion was being drowned out or completely ignored. I realize the reviewers have a great deal of experience doing these reviews, and I have enjoyed reading each and EVERY one of them, including the bench portions. I may be somewhat new to the site from a postings point of view, but had been lurking for a good time before entering the fray and have been active in the business of espresso for almost eleven years.

RapidCoffee wrote:Oh, I will (try tamping lighter with multiple pulls). But remember, I'm not the one making any claims. What evidence supports the "light tamp => multiple pulls won't fracture the puck" hypothesis? And just to play devil's advocate, why wouldn't a firmer surface (from a harder tamp) resist fracturing to a greater extent on multiple pulls?

Thank you John for trying. That is all I wanted, as it very well may not help you, but it also might.

As to the evidence, I have seen it myself on numerous occasions on these machines, but YMMV. I can't really give you a precise reason why this works, but I can tell you about my own personal experiences.

The harder the tamp and the firmer the puck the more likely that air being pulled up into the puck on an upstroke(downstroke for springs) will force its way through in the form of a crack in the puck. This crack WILL become a channel when you start the second pull. My experience with light tamps have been that I rarely if ever see the evidence of this in the puck after the shot is pulled. So do I have evidence, yes. Would it stand up in a court of law? I can't imagine it would. Will it stand up to scrutiny by others? Maybe. I suppose we will see.

HB wrote:It's the weekend, isn't everyone supposed to be relaxing? Please keep the suggestions coming, they will be acted upon in due course.

I am relaxing, which is why I am taking time to post. So in the interest of relaxation let me make one quick point that I think my help put some of us lever users comments into a different perspective.
Posting to these forums only uses words, whereas most of the communication that goes on between people in person is nonverbal. We are all missing out on that here, and tend to read others posts and react out of our own mood at that moment. I know that many of the lever fans posts to this bench thread so far, may seem slightly hostile at times, or aggressive, but remember you are missing out on our facial expressions, which personally have been largely smiles. I am VERY happy and grateful that you guys are doing this review! Too little has been done to help newbie lever users decide on what they will be getting.

So to sum that up, I will hereby try to post my verbiage with the words "DON'T PANIC" written in large friendly letters on the front cover.