Bezzera Strega - Second Look - Page 23

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danetrainer
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#221: Post by danetrainer »

*somewhat OT, but I'm glad to see the Strega finally available and shipping...
I get the feeling that Cremina prices (new & used) will come down to a more realistic range again.

subq
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#222: Post by subq replying to danetrainer »

I hear that...I actually wanted a Cremina but I just don't think they are worth $4k. I suppose that's just a personal opinion though. Though to be honest, I'm more excited about getting the Strega. :)
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HB (original poster)
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#223: Post by HB (original poster) »

Since Jim's review is largely complete, I took the liberty of splitting follow-on discussion from recent owners to Owner experience with Bezzera Strega. If members have a question/comment specific to this review, reply here, otherwise reply to the new owner's thread or start another more specific Strega thread. Thanks.
Dan Kehn

subq
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#224: Post by subq replying to HB »

Interesting that thread is in "Espresso Machines" instead of "Lever Espresso Machines" :)
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allon
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#225: Post by allon »

It would be too much coding for it to appear in both groups, being a bit of a hybrid...
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farmroast
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#226: Post by farmroast »

It is very much a lever machine.
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HB (original poster)
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#227: Post by HB (original poster) »

I was thinking of the Strega's broader appeal to those who like levers and pump-driven espresso machines, so I split the thread to the Espresso Machines forum. Nothing more to it than that.
Dan Kehn

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mitch236
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#228: Post by mitch236 »

I have a question but admit to not reading the entire thread so I appologize in advance if this has been covered. Jim, you reduce the pressure as the shot progresses. Does that allow for a higher extraction yield than is possible at 9 bar? I went back and re-read your study of extraction yields where you state that most of the extraction occurs during the first 20 seconds regardless of shot time or weight. Does the diminishing pressure improve extraction yields past that 20 second mark? Have you done any investigation into what yields you are getting with the Strega?

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another_jim
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#229: Post by another_jim »

Hi Mitch,

I haven't done any extraction experiments. It's fairly clear that the extraction on the Strega is even more front-loaded than on other machines, since the preinfusion is long and at high pressure. However, despite the front loading, there is a very clear taste difference between different ways of running the lever later in the shot.

Of all the possible ways one could vary the shot on this style of machine, I only vary one parameter, the flow rate. I let the pump preinfuse until there's flow, then I cut the pump off. The compressed air then creates a flow that is initially strong, but tails off. I let it tail to the rate I want, then I let the lever up and retard to to stay at that rate. In other words, I only do steady flow shots; but some at a steady slower flow, so they take about 20 to 25 seconds to go from pump cut off to end, and some at a steady faster flow that only run 10 to 15 seconds.

If I want a shot that tastes like a dessert wine, i.e, the perfect Peppina/Microcasa shot; I run a slow flow/long time shot. If I want something more creamy and toasty, I do a fast flow/short time shot. These are closer to classic pump shots, but with the lack of bitterness one gets from commercial levers.

I'm pretty sure the difference between these two styles of shot is not in extraction, but in how the fats emulsify and modify the mouthfeel. The longer, lower pressure shots are less creamy, but if you let them cool, they would probably taste the same as the shorter, higher pressure shots.

The big news in terms of extraction is that there is no excuse for ultra-bitter shots from any machine. This super-bitterness comes from cooking and hydrolizing the coffee, so that the long chains molecules break down and get into the cup. This is not the good high extraction that gets the slower dissolving caramels into the cup, but the bad over extraction that breaks down the cellulose chains that should be insoluble and left for the termites.

The bad extraction happens when there's excessive heat, pressure and acidity. Clearly a spring lever is less prone to this, since the pressure diminishes and the temperature of the water stored in the group drops; but it is possible when doing an overly ristretto shot on a pump machine, especially an HX that heats up as the flow slows down. The Strega's immunity to overextraction gives a lot more leeway for doing pressure profiling without screwing the pooch.

I guess that if you added a rotary pump to any commercial multi-group lever/HX machine to get high pressure preinfusion, or added a gear pump to a double boiler machine to get the pressure to ramp up, and then ramp down again, you could achieve roughly the same effects.
Jim Schulman

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orphanespresso
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#230: Post by orphanespresso »

danetrainer wrote:somewhat OT, but I'm glad to see the Strega finally available and shipping...
I get the feeling that Cremina prices (new & used) will come down to a more realistic range again.
subq wrote: I hear that...I actually wanted a Cremina but I just don't think they are worth $4k. I suppose that's just a personal opinion though. Though to be honest, I'm more excited about getting the Strega.
:)



Maybe some of us will be around in 40 years to see how the 2012 Strega stands the test of time. There are a LOT of 40 year old Creminas out there still in service...many under the hand of HBers! We serviced a 1967 model and I don't have enough fingers and toes to figure out the age of that one...keep the lever pins lubed and they last forever.

But on topic....Jim, you are really working the pumps and pulls out to a science...very informative and adaptable to the other non pump levers as well. Since following your dissection of the Strega pulls I have been doing a lot of whoop-de-doos on the commercial Faema lever and enjoying it even more! Once in a while I get some bizarre result, mostly with SOs but still worthy of drinking and thinking about.