Gaggia Evolution - Temperature inadequacy and pull time issues

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MeTheGreat
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#1: Post by MeTheGreat »

Having just purchased a refurbished Gaggia Evolution and being less than amazed at the results, I tested the temperature of the extraction water and noted that the water was only at a mere 72°C upon reaching the cup (a Very hot cup). I have found that by engaging the steam function on the machine then turning on the pump 25 seconds after turning on the steam heater the water will reach ~83°C but unfortunately will be forwarded by a rather violent expulsion of steam for about 3 seconds.

Am I measuring temperature in the wrong place or what should the cup temperature be after extracting? If so where should I measure and what should it be?

Also, the shots I have pulled are extraordinarily fast for what I have read, the slowest I have managed even when trying to clog the machine is ~20 seconds, and with that the PF was completely filled with water when I removed it. I have tried many grind settings and tamps from nothing to 40 lbs and cannot get an appropriate extraction time. I have been able to achieve a hard dry puck with an extraction of about 15 seconds although the taste is rather undesirable.

Are there any suggestions for what to do to resolve this timing issue? Is the machine passing too much water too quickly? Any suggestions would help.

Also, because of my need of re-assurance... was this a good purchase? I still have the option of returning it and getting an upgrade without losing any money... I am willing to spend up to around $300 but just don't have the experience in the market to know...

Thanks for any help/advice.

mybs
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#2: Post by mybs »

Don't have much to offer in terms of temperature measurements, but I was able to pull quite adequate shots from an old Gaggia Coffee. What grinder are you using and how fresh are the beans? It sounds like you are not grinding fine enough for espresso. Remember that older coffee beans also tend to need a much finer grind. With a double, the machine should produce about 2 oz in around ~25 seconds. This means that the coffee must generate enough resistance to prevent more water from going through despite the high pressure being exerted. Since the Evolution does not have a 3-way valve, if you remove the portafilter right after brewing, it should be wet.

Are you giving the machine enough warm up time? Usually with Gaggias, you'll want to leave it on for about 15 minutes before pulling the shot that you're planning on drinking.

IMO, Gaggias tend to make great entry-level machines. This is particular true for people that aren't sure whether or not they like to brew espresso at home. They are truly value priced. If you match it with a decent grinder, good shots can be achieved. With only about $300 dollars to spend, the Gaggia is about right. You could get lucky and buy a used Rancilio Silvia if you look hard enough... Some people also advocate the Solis SL70 at around your price range. In either case, a good grinder and fresh beans are significantly more important.

MeTheGreat (original poster)
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#3: Post by MeTheGreat (original poster) »

Thanks for the reply. To be perfectly honest I am using a very bad grinder that usually produces more dust than grind (an old Krups GVX 1 a relative got me as a birthday present) and I also have no idea how fresh the beans are. I bought some from the only place in my area that sells whole beans that aren't sitting on a shelf and they weren't sure about the roasting date.

I am strongly considering a Rocky Doserless purchase in the next few days although I am also considering (hesitantly) going all out and just buying a Mazzer Mini so I won't have to upgrade at a later date (again... recommendations welcome). I also clearly see the need to order from a roastery to have fresh beans (the nearest one is about 95 miles away and any recommendations here would be fantastic).

I will try again with a higher grind although my previous experience has been that it chokes the machine and renders the group head filthy. I definitely have let the machine get up to temperature. I have waited between 10 and 40 minutes with the machine on before pulling a shot and the results are fairly uniform (between 70-76 degrees Celsius).

Thanks again

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HB
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#4: Post by HB »

MeTheGreat wrote:Thanks for the reply. To be perfectly honest I am using a very bad grinder that usually produces more dust than grind (an old Krups GVX 1 a relative got me as a birthday present) and I also have no idea how fresh the beans are.
Game over. Jim cited such a grinder as Exhibit A in The Home Barista's Guide to Espresso:

Image
Fake flat burrs - knobs crush beans
another_jim wrote:Finally there are contraptions falsely called burr grinders that cost around $50. These are not actually burr grinders, but use knobs to crush the beans. Since this produces a large quantity of fines, they will produce an acrid shot with even the most mild mannered all-Brasil blends. They are to be strictly avoided for any coffee use. Whirling blade grinders (that look like tiny blenders or food processors) are also to be avoided, since they too produce excessive dust.
I don't think you'll regret buying the best grinder you can afford. And if I'm wrong, they often sell used upwards of 70% of their retail value. Heck, some eBay buyers pay nearly retail for beatup old cafe grinders. :roll:
Dan Kehn

MeTheGreat (original poster)
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#5: Post by MeTheGreat (original poster) »

I have to say I actually laughed out loud when I looked at that article again... I had read it before and knew I had that exact kind of grinder, but was unaware that the example was in fact my poor grinder exactly. :oops: As a way of helping me decide primarily between the Mazzer Mini and the Rocky Doserless, how much difference are we really talking about for an extra $160? Are we talking about the difference between the University of Texas and Harvard? How much of a difference is there really.

In an update from my last post I did try a much finer grind (I bit the bullet and bought Illy Extra Fine espresso grind as my grinder clearly can't cut it) and experimented with several tamp strengths but still cannot get past the ~18 second extraction mark. Several shots had rather obvious channeling but still timed the same as those that looked like clean pulls. I had one particular shot that Looked beautiful with a lovely layer of lasting crema but tasted rather watery while another shot (which I tamped harder) was miraculously bitter with a small film of crema that dissipated quickly.

Should I be concerned with the extraction time at all? Any suggestions for my technique that may improve shot quality?

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jrtatl
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#6: Post by jrtatl »

MeTheGreat wrote: Are we talking about the difference between the University of Texas and Harvard? How much of a difference is there really.

Seriously, UT is one of the finest public universities in the country. Please don't disparage it, or imply that it is a Rocky to Harvard's Mazzer.
Jeremy

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HB
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#7: Post by HB »

MeTheGreat wrote:As a way of helping me decide primarily between the Mazzer Mini and the Rocky Doserless, how much difference are we really talking about for an extra $160?
It's not night and day, but several comparisons including my own of the in-cup result concluded the Mini is noticably better, plus there's the finer adjustment. I upgraded from the Rocky Rancilio and don't regret it. Once you accept that the grinder is truly king and start comparing against some seriously pricey grinders (e.g., Mazzer Robur, Versalab M3) do you realize how far from the top of the mountain even the Mighty Mini is. I'm always mulling over another upgrade; the biggest factor holding me back (besides the price!) is the size of monster commercial grinders.
MeTheGreat wrote:Any suggestions for my technique that may improve shot quality?
Diagnosing technique without using fresh whole bean coffee and a good grinder is invariably frustrating. Absolutely perfect technique handicapped by the grinder and coffees you describe (i.e., unknown roast date = optimistically weeks, probably months post-roast; preground Illy is even worse) would struggle to be judged passable.
Dan Kehn

MeTheGreat (original poster)
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#8: Post by MeTheGreat (original poster) »

Sorry to offend jrtatl, I also do indeed love UT (from Texas) and perhaps that was not a good comparison as the comparison I meant to make was from great to better, I was just wondering what the scope of the difference was. No disparaging meant.

More on the grinder, and I guess I should just make a decision and stop agitating about it... Is it really worth the extra for a relative novice to go for the upgrade?

Thanks for the slap about my bean/grinder use Dan. But more to the topic of my post, should I be worried about the pull temperature and time? I really would hate to have my continued experimentation and progress hampered by something like that and would definitely like to resolve it now as I still have a chance to exchange the machine. I would also like to know if I'm being paranoid and should sit down and shut up. In short, how big of a deal is the temperature and what is the best way to check it?

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HB
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#9: Post by HB »

MeTheGreat wrote:But more to the topic of my post, should I be worried about the pull temperature and time?... In short, how big of a deal is the temperature and what is the best way to check it?
It's a really big deal, but evaluating it with any level of precision costs beaucoup bucks (e.g., a thermofilter and Fluke will set you back more than $450). Sticking a thermometer through the side of a foam cup, pressing it tightly against the grouphead, then pulling a blank shot will give you the best low-cost ballpark figure of the brew temperature. Measuring the actual espresso as you noted in your first post yields no meaningful data.

Assuming you square away the fresh coffee and grinder issue, I would focus on the taste. It may seem to demand more time and waste coffee, but in the long run you'll learn more (my mini diatribe on the subject: The problem is on the handle side of the portafilter).

Closing thoughts... You can always spend more on espresso machines. The advice quoted below is spot on:
mybs wrote:IMO, Gaggias tend to make great entry-level machines. This is particular true for people that aren't sure whether or not they like to brew espresso at home. They are truly value priced. If you match it with a decent grinder, good shots can be achieved. With only about $300 dollars to spend, the Gaggia is about right. You could get lucky and buy a used Rancilio Silvia if you look hard enough... Some people also advocate the Solis SL70 at around your price range. In either case, a good grinder and fresh beans are significantly more important.
Dan Kehn

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jrtatl
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#10: Post by jrtatl »

MeTheGreat wrote:Sorry to offend jrtatl,
Actually: my bad. After a few adult beverages last night, I guess I was overly sensitive about my alma mater. But, having spent 5 years at UT, I think your comparison was apt. I'll be the first to admit that UT is no Harvard. (But, it's no slouch, either).
Jeremy

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