No crema

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LaitChaud
Posts: 5
Joined: 1 year ago

#1: Post by LaitChaud »

Machine: Fiorenzato Bricoletta
Grinder: Eureka Mignon Original/classic
Coffee beans: Welsh coffee co. medium roast blend (roast date 01/02/23

When I initially got the machine a month ago I was able to get a good amount of crema using "Kimbo - medium roast extra cream". Suddenly last week I found the crema was non existent, so I put it down to stale beans.

I bought fresh locally roasted beans, ran a descaling cycle, changed grind setting, tamping pressure etc etc. My shots are still showing no crema, they are neither bitter nor sour but don't have the complexity of flavour I have seen others achieve. When using a naked portafilter I can see the extraction start at the outer ring of the basket, but quickly filling to centre. I've lowered the dose to 14g, and I'm getting 28g out in around 28s, still no crema.

It's come to the point I'm speculating if the pressure in the group head isn't sufficient due to an issue with the pump. I understand crema isn't the most significant part of a good espresso, but considering i was able to produce it before & can't now I feel it may be a sign of something else going on. I'm still very early on in my espresso exploration, so I've searched all forums and people seem unsure on the diagnosis.

If anyone can help with any info or thoughts I'd be very grateful. Thanks in advance.

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mrgnomer
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#2: Post by mrgnomer »

So many variables it's hard to say. How old is your grinder? If it's new it may need a few pounds for the burrs to season.

What's the change in ambient temperature and humidity from the day you were getting good crema to the day you weren't? I seem to get the best exractions on cold, dry days. On hot, humid days the grinder can be hard to dial in. I also seem to have to be more careful with distribution, tamping and extraction.

Crema is also greater with dark roasts, especially classic Italian that blend in robusta. I can usually get crema from old store bought Kimbo or Lavazza roasts. Those roasts work on a coarser grind compared to fresh medium or light roasts. Light roasts I grind the finest for 1:2 extractions in 30 or so seconds and expect the least crema. If you can control extraction pressure and temperature, high for both brings out more in really light roasts and progressively lower as the roasts go darker works best for me to balance out bitterness vs sourness.

Experimenting with changing one parameter at a time eventually gets to what works. Grind, dose, distribution, tamp/tamper, preinfusion time, temperature, extraction pressure are parameters I play with along with basket type every now and again. For tamper type, an american curve convex works well for dark roasts and a flat works with light roasts.
Kirk
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erik82
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Joined: 12 years ago

#3: Post by erik82 »

You should test pressure at the grouphead. Your beans aren't stale and the machine and grinder should be able to create enough crema. Or you've got a really bad roast but that's mostly not the case. No crema should mean around only 2-3 bar of pressure. Best to rule that part out first with a manometer portafilter.

LaitChaud (original poster)
Posts: 5
Joined: 1 year ago

#4: Post by LaitChaud (original poster) »

mrgnomer wrote:So many variables it's hard to say. How old is your grinder? If it's new it may need a few pounds for the burrs to season.

What's the change in ambient temperature and humidity from the day you were getting good crema to the day you weren't? I seem to get the best exractions on cold, dry days. On hot, humid days the grinder can be hard to dial in. I also seem to have to be more careful with distribution, tamping and extraction.

Crema is also greater with dark roasts, especially classic Italian that blend in robusta. I can usually get crema from old store bought Kimbo or Lavazza roasts. Those roasts work on a coarser grind compared to fresh medium or light roasts. Light roasts I grind the finest for 1:2 extractions in 30 or so seconds and expect the least crema. If you can control extraction pressure and temperature, high for both brings out more in really light roasts and progressively lower as the roasts go darker works best for me to balance out bitterness vs sourness.

Experimenting with changing one parameter at a time eventually gets to what works. Grind, dose, distribution, tamp/tamper, preinfusion time, temperature, extraction pressure are parameters I play with along with basket type every now and again. For tamper type, an american curve convex works well for dark roasts and a flat works with light roasts.
I purchase my grinder second hand, and it's the original model so I'm guessing atleast 5 years. I've not had a good look at the burrs yet, but from the age they're not under seasoned.

In terms of ambient temp etc. the change happened in a matter of days so I'm assuming it's not to do with that. I can get a thin layer of crema with the kimbo but that's very fine grind to the point it's incredibly bitter.

Regardless of how I grind the initial flow is very slow and dark, then I can hear the pump kick in more and the pressure rises but by that point there's already 10g of espresso in the cup. I'm not getting any results like others I've seen in terms of constant & powerful flow, even when I'm getting 30g in 30s.

I'll certainly try out the convex tamper, seems a really good idea. Thanks for the knoweldge, it's greatly appreciated

LaitChaud (original poster)
Posts: 5
Joined: 1 year ago

#5: Post by LaitChaud (original poster) »

erik82 wrote:You should test pressure at the grouphead. Your beans aren't stale and the machine and grinder should be able to create enough crema. Or you've got a really bad roast but that's mostly not the case. No crema should mean around only 2-3 bar of pressure. Best to rule that part out first with a manometer portafilter.
Honestly very relieved to get this reply. I felt I was the only one who thought it could be the pressure in the group head, and people have been reluctant to question it & focus on the beans and the parameters I control.

Regardless of how I grind or tamp, even with 30g in 30s, the initial flow is dark and slow & after the first 10g the pump picks up and the flow increases. Even then the flow isn't constant, or powerful.

Difficult question to answer, but would it be relatively expensive to fix the pressure issue with the pump/ whatever's causing it? Thanks for the knowledge, it's really appreciated

Milligan
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#6: Post by Milligan »

That is a plumbed in machine correct? Usually they need a certain amount of line pressure to get to full pressure. A lot of time line pressure is already at 2-4bar. Most manufacturers have a minimum line pressure that you need. Perhaps check your supply line to make sure you are getting good flow and pressure? That is the easiest to check right away. Check the supply screen too. It could have calcium build up choking flow enough to reduce pressure at the group head but still flowing enough to reach your extraction times. Calcium build up can occur before your filters (if you use filters.) Oddball case if so.

erik82
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Joined: 12 years ago

#7: Post by erik82 »

You first need to test the pressure using a manometer portafilter or check the line feeding the machine for blockage if it's indeed a plumbed in machine. With my Strietman I'm getting a lot of crema even with 3 bar so you should be at only 1-2 bar max to not have crema.

If it's pressure related then it can be a lot more then only the pump so it's not as simple as swapping out the pump. You do need to do some more testing. And if you did a descaling without knowing when the last one was done then that can also be your problem. If the history of a machine if unknown and descaling hasn't been done in years then you need to descale by taking the whole machine apart. Descaling just the brew part with descaling solution running through the machine can dislodge all kind of scale and block numerous parts. So that can also be a problem.

LaitChaud (original poster)
Posts: 5
Joined: 1 year ago

#8: Post by LaitChaud (original poster) »

Milligan wrote:That is a plumbed in machine correct? Usually they need a certain amount of line pressure to get to full pressure. A lot of time line pressure is already at 2-4bar. Most manufacturers have a minimum line pressure that you need. Perhaps check your supply line to make sure you are getting good flow and pressure? That is the easiest to check right away. Check the supply screen too. It could have calcium build up choking flow enough to reduce pressure at the group head but still flowing enough to reach your extraction times. Calcium build up can occur before your filters (if you use filters.) Oddball case if so.
It's a water tank machine, so luckily no issues with low pressure plumb line. I've done some troubleshooting and found that the pressure takes 30 seconds to build to 14 bar with a backwash puck. Then tested with a shot and the bar pressure was sitting at 1 bar, so I'm assuming it's a pump or flow issue. Thanks for your comment!

LaitChaud (original poster)
Posts: 5
Joined: 1 year ago

#9: Post by LaitChaud (original poster) »

erik82 wrote:You first need to test the pressure using a manometer portafilter or check the line feeding the machine for blockage if it's indeed a plumbed in machine. With my Strietman I'm getting a lot of crema even with 3 bar so you should be at only 1-2 bar max to not have crema.

If it's pressure related then it can be a lot more then only the pump so it's not as simple as swapping out the pump. You do need to do some more testing. And if you did a descaling without knowing when the last one was done then that can also be your problem. If the history of a machine if unknown and descaling hasn't been done in years then you need to descale by taking the whole machine apart. Descaling just the brew part with descaling solution running through the machine can dislodge all kind of scale and block numerous parts. So that can also be a problem.
I've done some troubleshooting and found that the pressure takes 30 seconds to build to 14 bar with a backwash puck. Then tested with a shot and the bar pressure was sitting at 1 bar, so it seems you're absolutely right. It's going into a specialist to diagnose further. Really appreciate your comments, cheers !

vecchi della seattle
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#10: Post by vecchi della seattle »

Are you pouring into a real espresso cup like the Inker 2.7oz? https://idrinkcoffee.com/products/inker ... 11-colours