Owner experience with Bezzera Strega - Page 100

May 22nd, 2016, 7:00 am

I decided to use a foil baking form.

#992: Post by **baldheadracing** » May 22nd, 2016, 2:07 pm

ravco wrote:Thanks. That is a very good alternative. Looks easy and cheap. I will give it a try. Probably doesn't catch up all the water, but most of it I expect.

The valve easily comes apart so the silicone cup can form a gasket between the top 'nut' and the rest of the valve - no leaks possible

.

#993: Post by **ravco** » May 26th, 2016, 2:23 pm

I'm working on the right temperature setting after PIDing my grouphead-heaters. There are various reference target temperatures for instance in the "how to cool it"-thread and different graphs with grouphead temperatures, which are a help. The original thermostat (Campini Ty60 T210) has 95 C printed on the side (and "14-14"?). I've been trying to find out what the exact on- off-temperatures are, but haven't had any luck so far. Are 95 C the maximum or the middle of the range? All I could find was "tolerance intervention +/-5K". Don't know if that has anything to do with it. One of Erics' graphs with the grouphead temperature at different points shows a range of 185F to 209F (85 to 98.5C) at point 3 (just in front of the thermostat). That would be a range of 13.5 C and would indicate that 95C is somewhere in the middle of the range.

#994: Post by **another_jim** » May 26th, 2016, 5:24 pm

ravco wrote:I'm working on the right temperature setting after PIDing my grouphead-heaters.

You can get more consistent shots by just setting it to 95C and removing the dead band effect. A more adventurous policy is to adjust the group head and boiler in tandem. The boiler temperature will determine the initial temperature; the group temperature will control the drop off. At the stock settings, shots start around 96C and drop down to 90C - 93C (the variation in the drop down is probably affected by the mechanical thermostat's dead band). IMO, the stock settings work quite well with most coffees.

Let us know what you find.

#995: Post by **Jolly** » June 8th, 2016, 2:50 pm

Today I noticed something odd, while performing a lube-job. The top tray (officially CUPS-HEATER GRID, partno. 5074616LW) appeared stuck trying to lift it off. Well, it appeared to be ... glued: On the right side, both rubber protective caps under the tray may have deteriorated because of heat, and have become sticky.

I do not think temperature conditions have changed over the years, and when I measure the temp of the assembly directly under the tray, it is 70 degrees Celsius. I do not think that is excessive - about the temperature for a cup-heater.

Anyone noticed something similar?

#996: Post by **ravco** » June 8th, 2016, 3:24 pm

When my Strega was brand new the top tray seemed fixed to the top of the machine. It needed a good pull to get it off. Turned out it was just the rubber caps sticking to the metal. Never had the problem again.

#997: Post by **photobillyli** » July 22nd, 2016, 12:53 am

i am thinking of ordering a strega
but i accidentally watched a review video on another spring lever machine and one of its selling points is "true low-pressure pre infusion"
however as far as i know strega has a vibe pump to fill the group head and it pre infuses coffee at high pressure [9 bar, right?].
so here comes my questions:
1. Should coffee be pre infused at high presure or low pressure?
2. normal spring lever doesnt have the vibe pump to fill the group head, so it is normal to have TRUE low-pressure pre infusion in spring lever, so why does the strega incorporate a vibe pump to fill the group head if low pressure pre infusion is better over high pressure?
3. when i check the video of strega, i found the vibe pump is triggered as the lever is at its lowest position. so if i wanna to pre infuse at low pressure, how about if i pull down the lever to a position before it can trigger the vibe pump. Then i should have low pressure pre infusion like normal spring lever, shouldn't i??

thank you so much~

#998: Post by **BartG** » July 22nd, 2016, 3:50 am

photobillyli wrote:i am thinking of ordering a strega
but i accidentally watched a review video on another spring lever machine and one of its selling points is "true low-pressure pre infusion"
however as far as i know strega has a vibe pump to fill the group head and it pre infuses coffee at high pressure [9 bar, right?].
so here comes my questions:
1. Should coffee be pre infused at high presure or low pressure?
2. normal spring lever doesnt have the vibe pump to fill the group head, so it is normal to have TRUE low-pressure pre infusion in spring lever, so why does the strega incorporate a vibe pump to fill the group head if low pressure pre infusion is better over high pressure?
3. when i check the video of strega, i found the vibe pump is triggered as the lever is at its lowest position. so if i wanna to pre infuse at low pressure, how about if i pull down the lever to a position before it can trigger the vibe pump. Then i should have low pressure pre infusion like normal spring lever, shouldn't i??

thank you so much~

Hi, welcome to the forum!

I'll try to answer some of your questions. Simply put, water needs to move around in a coffee machine. This can be done by a pump (10 bar), by the pressure of the water mains (2 to 4 bar) or boiler pressure (1,5 bar or less). There are other methods but those 3 are most commonly used.
When designing a coffee machine different factors come into play: cost, practicality and quality. The Strega is an unusual lever machine because the grouphead has separate heating and the brew water is moved to it by a pump. But the pump is normally not used to pressure the water through the coffee puck (it can be though).
However the design of the Strega is quite successful, everything works well together (heat exchanger, pump filled grouphead, separate heating of grouphead, spring pressure), which makes it a quality machine.

I think - but can be wrong - that when the grouphead is filled by the pump the pressure on the coffee puck is not 10 bars but much lower.

You could do what you describe in question 3. For that you would have to grind coarser (because you shorten preinfusion time). And your coffee will probably be less tasty.

#999: Post by **erik82** » July 22nd, 2016, 8:08 am

Question 3 won't work (I owned a Strega for 4 years). It'll give no water or fill the cylinder through the pump, nothing in between. The pump starts and 0 bar and builds like any E-61 with vibe pump will also do. The cylinder is big enough that you don't have to fill it to the max. Filling it halfway is more then enough.

Filling the cylinder to the will give you about a 0-10 bar pre-infusion and 11-8 bar extraction.
Filling half of the cylinder will give you about 0-7 bar pre-infusion and 8-5 bar extraction.

The Strega is a really nice machine and nothing will beat it for that price. Don't expect the really soft shots of a traditional lever but also don't expect the hard shots of a E-61. It'll be somewhere in between but more towards a traditional lever.

#1000: Post by **another_jim** » July 22nd, 2016, 1:50 pm

erik82 wrote: Filling the cylinder to the will give you about a 0-10 bar pre-infusion and 11-8 bar extraction.
Filling half of the cylinder will give you about 0-7 bar pre-infusion and 8-5 bar extraction.

That's it exactly.

If you are inclined to believe in things like a (ta da) T-R-U-E (ta-da) preinfusion pressure, you can set the Strega up to get fairly close to it. On the other hand, I don't think Bezzera is willing to issue a certificate that you are now making (ta-da) T-R-U-E (ta-da) espresso. If you want such a certificate, you'll have to go elsewhere.