Coffee Grinder for Espresso Machine?

[TooManyGuitars]

Well my cheapish Breville grinder - which i got for free in my Buy Nothing group ($80 new) - seems to have died over the weekend.  I used it to fine grind beans for my Breville espresso machine which I purchased 2nd hand for $60 ($200 new). 

Now, I can't get my beans ground up fine enough to make a decent latte and I am torn about what to do.  Articles I am reading - written by coffee snobs who are way snobbier than me - suggest that spending $400 or more on a grinder is a reasonable thing fo a home coffee drinker to do.  I don't want to spend anything like that, but I've now been through 2 sub$100 grinders in the last year though - they just don't seem to last. 

Recommendations???

[Larabeth]

http://www.amazon.com/gp/product/B004T6EJS0?psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s01

This is the one we have and I love it.  We bought it new, but it quickly paid for itself.  Check the one star ratings, you may not think it is worth your time... but the overall ratings are positive.

We've had it nearly a year, use it every day for espresso drinks, french press, and drip coffee... maybe we are lucky but it seems like more often than not people have a good experience with this grinder.

[Tetsuya Hondo]

http://www.oehandgrinders.com/OE-Manual-Coffee-Grinders_c_1.html

[cbr shadow]

I second Orphan Espresso grinders if you don't mind grinding by hand and want a very high quality cup of coffee.  I have the Pharos (which I'm going to be selling soon :) ) and absolutely love it.  Definitely don't cheap out too much on the grinder though, as it's more important than the espresso machine.
In the end if you don't really taste a difference between a drink from a cheap grinder and a drink from a high-end grinder then that's great - just get the cheaper one! 
I put a lot of value into being able to make a really nice latte at home, but I understand plenty of people would think it's a waste.

[horsepoor]

I've had the Baratza Virtuoso with the upgraded burr for about 3 years now and have been really happy with it.  I just do drip, not espresso, but it seems like the grind is very consistent and adjustable.  I bought it new on eBay for around $190, IIRC.

[CATman]

http://www.amazon.com/gp/product/B004T6EJS0?psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s01

This is the one we have and I love it.  We bought it new, but it quickly paid for itself.  Check the one star ratings, you may not think it is worth your time... but the overall ratings are positive.

We've had it nearly a year, use it every day for espresso drinks, french press, and drip coffee... maybe we are lucky but it seems like more often than not people have a good experience with this grinder.

I can second this. My SO have this same grinder and she uses it daily. It works great in the french press and keurig (the very mustachian refillable pods ;)). The grind is very consistent so I think it would works great for an espresso machine.

[TooManyGuitars]

Since posting, I have discussed this with a couple of Mustachians here at work...their recommendation was buy pre-ground beans.  I know the true coffee snobs scoff at such a suggestion...what does the MMM community think?

[Larabeth]

Since posting, I have discussed this with a couple of Mustachians here at work...their recommendation was buy pre-ground beans.  I know the true coffee snobs scoff at such a suggestion...what does the MMM community think?

That definitely is an option, especially if you go through a large amount of beans/add a lot of cream or sugar and won't notice if the coffee is somewhat stale.

It saves you from having to buy a grinder, so technically it could be a better choice for you.  I like my fancy coffee and I like to be able to grind it to whatever specifications I need for whatever I'm making (like I said, we use several different ways of brewing), so for me I would rather pay for a grinder.

[Telecaster]

Well my cheapish Breville grinder - which i got for free in my Buy Nothing group ($80 new) - seems to have died over the weekend.  I used it to fine grind beans for my Breville espresso machine which I purchased 2nd hand for $60 ($200 new). 

Now, I can't get my beans ground up fine enough to make a decent latte and I am torn about what to do.  Articles I am reading - written by coffee snobs who are way snobbier than me - suggest that spending $400 or more on a grinder is a reasonable thing fo a home coffee drinker to do.  I don't want to spend anything like that, but I've now been through 2 sub$100 grinders in the last year though - they just don't seem to last. 

Recommendations???

I have one of these sub-$100 grinders, which I've used daily, sometimes twice daily for a few years:

http://www.amazon.com/Capresso-560-01-Infinity-Grinder-Black/dp/B0000AR7SY/ref=sr_1_1?ie=UTF8&qid=1454480262&sr=8-1&keywords=capresso+infinity+burr+grinder

Works great, no complaints.

Now, I really love espresso, but I'm not an ultra-snob.  There might be higher end models that give a more consistent grind or some such, but performance wise I can't tell any difference. 

[Bertram]

Espresso Scientist here. There is two reasons how the grinder affects the taste:
- how fine you can choose different levels.
- how consistent in size the grind is

Next consideration is the longevity of the machine and whether you can spare parts after a few years.

Incidentally there is some correlation between what makes it precise and consistent, and well you can repair it. I bought one in Germany that cost around 120€ which is OK in all regards. The trick is in the bean! There are some espresso beans that are super difficult and will taste horrible when even a little bit is off. There are other beans which are very flexible and always kind of work out.

So unless you are very picky about the the types of espresso beans you want, you will be fine with a medium priced model. Just switch the beans if you run into problems. (Obviously you want locally roasted ones, not store packaged).

[sistastache]

I also purchased this grinder after it was recommended to me by a business that used it for large quantity batches of grinding regularly. Two years strong and still running like a champ for me!

Well my cheapish Breville grinder - which i got for free in my Buy Nothing group ($80 new) - seems to have died over the weekend.  I used it to fine grind beans for my Breville espresso machine which I purchased 2nd hand for $60 ($200 new). 

Now, I can't get my beans ground up fine enough to make a decent latte and I am torn about what to do.  Articles I am reading - written by coffee snobs who are way snobbier than me - suggest that spending $400 or more on a grinder is a reasonable thing fo a home coffee drinker to do.  I don't want to spend anything like that, but I've now been through 2 sub$100 grinders in the last year though - they just don't seem to last. 

Recommendations???

I have one of these sub-$100 grinders, which I've used daily, sometimes twice daily for a few years:

http://www.amazon.com/Capresso-560-01-Infinity-Grinder-Black/dp/B0000AR7SY/ref=sr_1_1?ie=UTF8&qid=1454480262&sr=8-1&keywords=capresso+infinity+burr+grinder

Works great, no complaints.

Now, I really love espresso, but I'm not an ultra-snob.  There might be higher end models that give a more consistent grind or some such, but performance wise I can't tell any difference.

[Tetsuya Hondo]

Since posting, I have discussed this with a couple of Mustachians here at work...their recommendation was buy pre-ground beans.  I know the true coffee snobs scoff at such a suggestion...what does the MMM community think?

If you're a latte drinker (not that there's anything wrong with that), you may not notice much of a difference depending on how much milk you use. If you use any sweeteners or flavorings, then it really doesn't matter that much.

However, if you do any straight espresso or anything with less milk, then you will notice. When pulling a shot, I can tell how old my beans are by the taste and flow and can adjust the grind for those changes. The problem with pre-ground is you can't make adjustments. Another problem of pre-ground is that after a few weeks, beans start to lose their mojo. For example, I'm currently enjoying a shot pulled from beans roasted about six days ago. It's like night and day between the shot I pulled yesterday from the same blend that was roasted three weeks ago. As for the pre-ground, who knows when they were roasted. They're essentially DOA. A better option might be to buy whole beans and just grind them at the store, if you can find a grind that works for your shots.

Now if any of this sounds goofy to you, and you haven't experienced any of this, then by all means get the cheap grinder or give the pre-ground a try. Espresso making is one of those traps that MMM warned you about. Once you start down the road you can't help but look for the next higher high. Next thing you know you'll be strung out on the pure, uncut Ethiopian shit staring bleary eyed at your computer screen in the wee hours of the morning shopping for 40 year old vintage hand pump espresso machines. It's a dark road, my friend.

[Tetsuya Hondo]

I second Orphan Espresso grinders if you don't mind grinding by hand and want a very high quality cup of coffee.  I have the Pharos (which I'm going to be selling soon :) ) and absolutely love it.  Definitely don't cheap out too much on the grinder though, as it's more important than the espresso machine.
In the end if you don't really taste a difference between a drink from a cheap grinder and a drink from a high-end grinder then that's great - just get the cheaper one! 
I put a lot of value into being able to make a really nice latte at home, but I understand plenty of people would think it's a waste.

Why are you selling your Pharos?

I've really been blown away by mine. And I can't believe that I rarely have to adjust it. I don't know what dark magic is involved but once it's dialed in it's like it handles about anything.

[Bertram]

Once you start down the road you can't help but look for the next higher high. Next thing you know you'll be strung out on the pure, uncut Ethiopian shit staring bleary eyed at your computer screen in the wee hours of the morning shopping for 40 year old vintage hand pump espresso machines. It's a dark road, my friend.

I mean, who doesn't have that Kopi Luwak on his bucket list... ;)

[Tetsuya Hondo]

Once you start down the road you can't help but look for the next higher high. Next thing you know you'll be strung out on the pure, uncut Ethiopian shit staring bleary eyed at your computer screen in the wee hours of the morning shopping for 40 year old vintage hand pump espresso machines. It's a dark road, my friend.

I mean, who doesn't have that Kopi Luwak on his bucket list... ;)

I raise my own civit cats for this purpose. Once you've had freshly shat beans, you won't go, nay, you can't go back.

[YK-Phil]

I raise my own civit cats for this purpose. Once you've had freshly shat beans, you won't go, nay, you can't go back.

I wonder if any cat will do. My wife and I are planning a six-month road trip next winter, and the cat is tagging along, whether I like it or not. As I can't start the day without my espresso, I could at least get some use out of this lazy bastard.

[zephyr911]

I'm a semi-snob about espresso (won't buy it in AL because I make better at home) but I've managed to avoid getting too picky about the grind. I found a passable one for $1.99 at a thrift store to go with my ROK machine and never went back. Would like to get the ROK grinder to match but not till this one dies will I even consider it.

[NESailor]

Surprised nobody mentioned the trusty (and cheap) Hario Skerton?  I got one about 2 months ago and have been using it daily.  I have a decent entry level machine  (Gaggia Classic) and buy whole bean coffee from a few sources.  The Hario does a good enough job that I don't complain - though, I'm not a huge snob and I DO drink mostly whole milk cappuccinos (no sugar).  I'm fairly cost-conscious so I would find it very hard to justify a premium grinder for an increase in quality that I probably wouldn't notice/appreciate.

[Tetsuya Hondo]

I wonder if any cat will do. My wife and I are planning a six-month road trip next winter, and the cat is tagging along, whether I like it or not. As I can't start the day without my espresso, I could at least get some use out of this lazy bastard.

I encourage you to embark on a month long study of the topic. Be sure to post follow up video of yourself carefully extracting the beans from your litter box bombs.

[Tetsuya Hondo]

Surprised nobody mentioned the trusty (and cheap) Hario Skerton?  I got one about 2 months ago and have been using it daily.  I have a decent entry level machine  (Gaggia Classic) and buy whole bean coffee from a few sources.  The Hario does a good enough job that I don't complain - though, I'm not a huge snob and I DO drink mostly whole milk cappuccinos (no sugar).  I'm fairly cost-conscious so I would find it very hard to justify a premium grinder for an increase in quality that I probably wouldn't notice/appreciate.

From an MMM perspective, this is probably the right answer. Inexpensive. Pretty good grind (probably better than the low end burr grinders - in fact you can get more bang for your buck with the hand grinders than electrics, for example, the Pharos has the same burr set as a $1600 Compak K10, one of the finest grinders you can buy). Muscle power over electric.

[NESailor]

From an MMM perspective, this is probably the right answer. Inexpensive. Pretty good grind (probably better than the low end burr grinders - in fact you can get more bang for your buck with the hand grinders than electrics, for example, the Pharos has the same burr set as a $1600 Compak K10, one of the finest grinders you can buy). Muscle power over electric.

I'll wear this as a badge of honor ;)  Also, coffee time is MY TIME.  Extending it by 1 minute while I hand grind my coffee is a bonus, not really "work" for me.

[zephyr911]

My next grinder will almost definitely be hand-powered.

[TooManyGuitars]

Thanks to all for the responses!  Awesome.

So we decided that we would set up a automated search for a second hand $300 new conical burr grinder on gumtree (Aussie Craigslist), and buy pre ground in the meanwhile. Looking to spend $80 or so.  Lo and behold, when I went to set up the daily search, I found a sunbeam em0440 for sale.  Unwanted gift, never used, still sealed up in the box...got it for  $60 AUD.  Works great, big step up from what we had before.  Problem solved!

I have gained some interest in the high end hand grinders though.  Maybe next time...

[golden1]

I can't understand why these grinders are so expensive.  Granted I am not a huge coffee snob, so I just have a the standard Krups grinder that cost $20.  Why are these conical burr grinders hundreds of dollars?  What is it about the grinder that makes it worth spending that kind of money for? 

[zephyr911]

I can't understand why these grinders are so expensive.  Granted I am not a huge coffee snob, so I just have a the standard Krups grinder that cost $20.  Why are these conical burr grinders hundreds of dollars?  What is it about the grinder that makes it worth spending that kind of money for?

The smug satisfaction of knowing you've distinguished yourself from the benighted masses who would never spend that kind of money on a grinder.

Not sure what else.

[Tetsuya Hondo]

I can't understand why these grinders are so expensive.  Granted I am not a huge coffee snob, so I just have a the standard Krups grinder that cost $20.  Why are these conical burr grinders hundreds of dollars?  What is it about the grinder that makes it worth spending that kind of money for?

If you do drip coffee, then the difference is incremental. If you do espresso, it makes a very big difference. A $20 blade grinder essentially hacks the hell out of beans. If you take a close look at the grounds, you'll see that they're all different sizes with lots of bean dust mixed in. The bigger burr grinders make more consistent grounds, which helps you eliminate one more variable in making espresso, which is a finicky bitch-goddess. If I made a shot for you with a blade grinder and then one on big burr grinder, you really would notice the difference.

Now, would I spend $1600 on one? Or, even $600 on one? Hells no. That's why I love the hand grinders. By doing without the the convenience of an electric motor, you can get a similar, if not equal grind (in the case of the Pharos) for a hundreds, if not a thousand, bucks less.

[Larabeth]

I can't understand why these grinders are so expensive.  Granted I am not a huge coffee snob, so I just have a the standard Krups grinder that cost $20.  Why are these conical burr grinders hundreds of dollars?  What is it about the grinder that makes it worth spending that kind of money for?

The smug satisfaction of knowing you've distinguished yourself from the benighted masses who would never spend that kind of money on a grinder.

Not sure what else.

+1

[MaikoTsumi]

I currently use the Baratza Preciso  http://www.amazon.com/Baratza-Preciso-Conical-Coffee-Grinder/dp/B00LW8QH1U/ref=sr_1_1?ie=UTF8&qid=1454600070&sr=8-1&keywords=preciso+grinder. 
Very good quality grind for a lower price than most. $299 brand new.

Listen, for those non-espresso types on here.  There is no cheaping out on a grinder.  Hand grinder's are great for the dabbler, but a real grinder is needed for a true espresso grind.  Although a good grinder will improve flavor and consistency on any type of coffee you drink, it is absolutely essential for espresso.  Other than the bean, there is no other component that affects the quality of the brew than the grinder.  It's often said, if you could afford only a cheap grinder and good quality espresso machine or good quality  grinder and cheap espresso machine, buy the grinder first.
    For you coffee drinkers who are skeptics, I was you at one time.  Every once in a while, I would have an awesome cup of coffee.  It was random and I would savor those fleeting moments and drink substandard coffee most other times.  I just thought that was the way it was, like other things in life.  It wasn't until I learned the process and bought a good quality grinder that I learned different.  I now have that amazing cup of coffee every single day.

[Tetsuya Hondo]

I currently use the Baratza Preciso  http://www.amazon.com/Baratza-Preciso-Conical-Coffee-Grinder/dp/B00LW8QH1U/ref=sr_1_1?ie=UTF8&qid=1454600070&sr=8-1&keywords=preciso+grinder. 
Hand grinder's are great for the dabbler, but a real grinder is needed for a true espresso grind. 

Whoa, whoa, whoa. Have you used some of the hand grinders out there nowadays? The Hario Skelton is actually a respectable grinder, even for espresso. Have you used the Orphan Espresso Lido? The OE Pharos? Ever checked out an HG One (although very spendy)? The latter two hold their own against any super titan electric grinder and will blow the Preciso out of the water. In shootouts conducted by the engineering nerds on home-barista.com (LOL, right? but they're a global collective of crazy obsessive enthusiasts that love to apply experimental designs to comparing equipment, mostly engineers) between the Pharos and Mazzer Roburs, Compak K10s, etc. (these are commercial grade $1500-2000 grinders) and concluded that it matched their grinds, which makes sense as they share similar sized burrs. Hand grinders provide a great way to experience high end grinds for a fraction of the cost.

But, I agree with your overall sentiment. Grinders matter for espresso. Grinders make more of a difference than the machine itself (assuming a reasonable baseline).

[zephyr911]

If you do drip coffee, then the difference is incremental. If you do espresso, it makes a very big difference. A $20 blade grinder essentially hacks the hell out of beans. If you take a close look at the grounds, you'll see that they're all different sizes with lots of bean dust mixed in. The bigger burr grinders make more consistent grounds, which helps you eliminate one more variable in making espresso, which is a finicky bitch-goddess. If I made a shot for you with a blade grinder and then one on big burr grinder, you really would notice the difference.

Fair enough, and I mostly use my grinder for drip so I may not appreciate the difference. Back when I was slinging espresso in Iraq (true story), we had a sweet burr grinder that I pretty much took for granted, but I've mostly been relying on pre-ground for my espresso lately. (Still better than my local cafes, and how sad is that?)

Wasn't 100% serious about the smug satisfaction, but I do think such a thing can be taken too far. ;)

[MaikoTsumi]

I didn't mean to imply that hand grinders do a bad job, it's just a tedious step that I prefer not to do.  I'm already putting a lot of time into the process.
 Espresso, the grind is essential, but a good grinder will improve your regular cup of joe as well.  French press coffee is more forgiving, but a consistent grinder will elevate a French press as well.

Full disclosure, I'm enough of a coffee geek to roast my own beans.

[golden1]

If you do drip coffee, then the difference is incremental. If you do espresso, it makes a very big difference. A $20 blade grinder essentially hacks the hell out of beans. If you take a close look at the grounds, you'll see that they're all different sizes with lots of bean dust mixed in. The bigger burr grinders make more consistent grounds, which helps you eliminate one more variable in making espresso, which is a finicky bitch-goddess. If I made a shot for you with a blade grinder and then one on big burr grinder, you really would notice the difference.

Okay this is the clearest explanation I have read regarding this.  I drink mostly French press coffee.  Is it worth getting a hand grinder for that? 

[zephyr911]

I didn't mean to imply that hand grinders do a bad job, it's just a tedious step that I prefer not to do.  I'm already putting a lot of time into the process.
 Espresso, the grind is essential, but a good grinder will improve your regular cup of joe as well.  French press coffee is more forgiving, but a consistent grinder will elevate a French press as well.

Full disclosure, I'm enough of a coffee geek to roast my own beans.

Now that's dedication. I looked into it and laziness got the better of me.

All the same, I may have to instigate a NORAL MMMeetup just to see what the fuss is all about.

[Tetsuya Hondo]

Wasn't 100% serious about the smug satisfaction, but I do think such a thing can be taken too far. ;)

Whaaaat?

[Steps back from cleaning off the fully plumbed, gold plated LaMarzocco GS3 with ivory and sapphire inlays and sets down his panda skin cleaning cloth. Wonders if things have gone too far. Wonders if such a thing has not been taken far enough.

Realizes he's not wearing pants.]

Okay this is the clearest explanation I have read regarding this.  I drink mostly French press coffee.  Is it worth getting a hand grinder for that? 

I can't say as I'm not a French press drinker, but the coffee nerds say YES! However, keep in mind that the hand grinder isn't for everyone, especially if you want to get out the door in a hurry. I'm attracted to anything old-timey or non-electric. It's also kind of a zen process for me, a morning ritual that I enjoy, as well as a wee bit of arm exercise. And not all hand grinders are equal. There's some that are crap, some pretty good, and some that are pretty awesome. Recommend checking out some of the online coffee dork habitats for better info and guidance. Although, be careful about going down that rabbit hole as some will convince you that you need a Ferrari when a Honda will do.

[zephyr911]

Wasn't 100% serious about the smug satisfaction, but I do think such a thing can be taken too far. ;)

Whaaaat?

[Steps back from cleaning off the fully plumbed, gold plated LaMarzocco GS3 with ivory and sapphire inlays and sets down his panda skin cleaning cloth. Wonders if things have gone too far. Wonders if such a thing has not been taken far enough.

Realizes he's not wearing pants.]

I actually have a brass-plated La Pavoni ($1600 new, last I checked) in my closet, but only because I saw it like new for $600 and figured I could make a few hundred on resale. I'm afraid to even use it.

If you think about it, being able to make espresso without pants on is just one more reason to DIY.

I'm attracted to anything old-timey or non-electric. It's also kind of a zen process for me, a morning ritual that I enjoy, as well as a wee bit of arm exercise.

Does anyone else have, or have you used/tried, one of these? (love mine)

[Tetsuya Hondo]

I actually have a brass-plated La Pavoni ($1600 new, last I checked) in my closet, but only because I saw it like new for $600 and figured I could make a few hundred on resale. I'm afraid to even use it.

If you think about it, being able to make espresso without pants on is just one more reason to DIY.

Does anyone else have, or have you used/tried, one of these? (love mine)

Ooooo. Is it a lever La Pavoni? I'm so tempted by them, especially as I may have killed my current machine. And the poor thing is just sitting in your closet?

Although, dammit, I'm trying to be frugal so I've been seriously kicking around the idea of your ROK. You say you've had good experiences with it? I've heard that you can get something that comes close to the lever machines but that it can be a PITA to get everything right. Also, some of the early models were breaking.

Is there anything you don't like about it? How steep was the learning curve when you got it?

[zephyr911]

Ooooo. Is it a lever La Pavoni? I'm so tempted by them, especially as I may have killed my current machine. And the poor thing is just sitting in your closet?

Yeah, it's this model. I was going to use it for fun and resell it but I'm too afraid I'll fuck it up. I started to unwrap it and got nervous, so I packed it up without even trying.

Although, dammit, I'm trying to be frugal so I've been seriously kicking around the idea of your ROK. You say you've had good experiences with it? I've heard that you can get something that comes close to the lever machines but that it can be a PITA to get everything right. Also, some of the early models were breaking.

I actually have the earlier model (Presso). Got it for $99 five years ago and have used it regularly, including some travel. Aside from some rust spots inside the outer shell of the portafilter (not where the coffee actually sits), and some gasket discoloration, it's functionally and aesthetically like new.

Is there anything you don't like about it? How steep was the learning curve when you got it?

I can't think of anything. A couple of times the gasket got folded up and wouldn't maintain pressure, which had me annoyed and concerned until I figured out the problem. It's pretty dummy-proof... heat water, pack espresso, pour water, arms up -> arms down.
Calibrating the resting time and press speed to your taste is a fun process, and I like being able to vary the product from day to day. If you want it one exact way, it'll take a few shots to dial it in.
They recommend running blank shots to heat the body before use, but I've always thought the first one (starting cold) came out perfect. After that one, I have to let it cool a bit to drink.

[Tetsuya Hondo]

Yeah, it's this model. I was going to use it for fun and resell it but I'm too afraid I'll fuck it up. I started to unwrap it and got nervous, so I packed it up without even trying.

I actually have the earlier model (Presso). Got it for $99 five years ago and have used it regularly, including some travel. Aside from some rust spots inside the outer shell of the portafilter (not where the coffee actually sits), and some gasket discoloration, it's functionally and aesthetically like new.

I can't think of anything. A couple of times the gasket got folded up and wouldn't maintain pressure, which had me annoyed and concerned until I figured out the problem. It's pretty dummy-proof... heat water, pack espresso, pour water, arms up -> arms down.
Calibrating the resting time and press speed to your taste is a fun process, and I like being able to vary the product from day to day. If you want it one exact way, it'll take a few shots to dial it in.
They recommend running blank shots to heat the body before use, but I've always thought the first one (starting cold) came out perfect. After that one, I have to let it cool a bit to drink.

That's a beautiful La Pavoni. I've considered the Europiccolo (sic?) model, which is nearly half the coin but very similar internally. Even at its price though, the the little MMM on my shoulder smacks me upside the head.

Appreciate the insights on the ROK/Presso. If my current machine finally blows up, versus just eating parts a steady diet of replacement valves and gaskets, I think I'll give it a try.

[EnjoyIt]

For those that don't understand why a grinder is important:

Picture ground coffee that has grinds that are differently sized.  If you can imagine hot water pushed through those grounds under pressure.  You can now easily see that water will flow through the bigger grounds faster and may barely even traverse the more finely ground beans.  this results in some ground being over expressed and others being under expressed.  Coffee that is under expressed is sour very nasty.  Beans that are over expressed are bitter.  Just imagine drinking a shot of sour bitter blackness.  Not very good is it?  A good burr grinder will ideally have every ground the exact same size allowing the hot water to be pushed through evenly and perfectly making that perfect shot of espresso.

[zephyr911]

Chemically, sour and bitter neutralize each other.
But the ground size does seem relevant for a couple of reasons, especially to a ristretto fan. Someday when I'm rich maybe I'll spring for a hand-cranked burr grinder. ;)