I'm looking for some objective evidence regarding burr size in relation to taste / body of an espresso shot. I've found subjective evidence, but I'm more looking for some blind taste tests or an explanation involving math.

So far I've found two theoretical advantages of a larger burr set: 1) larger burrs produce less heat and 2) larger burrs take less time to grind and therefore the coffee is less stale. I believe both could be mitigated / would not really make a huge difference in the end.

So, is there anything else to a larger set of burrs?

Thanks.

Check this out. Titan Grinder Project. Lots of objective information there. Also, lots of reading.

Thanks! I'll give it a read tonight.

This thread will give you some more clues.

Small flat vs. large flat vs. conical burrs: Taste differences?

Cool, thanks!

After going through all the posts and articles and scientifical evidence I've come to the following conclusions:

1) Blade geometry makes a difference, i.e. conical vs. flat burrs. This was demonstrated by the microscopic analysis of grounds. It appears grounds from conical burrs produce a (generally) different shape than flat burrs.

2) Different grinders will grind differently, regardless of burr size, and therefore taste differently. Not necessarily better or worse, but different. This could be slight or readily noticeable depending on the grinders. Again, this was demonstrated by the microscopic analysis of grounds.

3) Construction / burr alignment is more important than burr size. A poorly constructed grinder with big burrs will produce less favorable and less consistent espresso than a solidly built grinder with smaller burrs.

1) and 2) appear to have been validated by testing, both blind and sighted.


My original question seems, for the most part, to go unanswered at the moment. One main reason is that most of the tests focused on larger, high quality "titan" grinders. Additionally, blind taste testing is a bit tricky for several reasons. This leaves the individual end user little choice but to buy various equipment and test it themselves.

So, because there is a lack of any solid evidence to suggest otherwise, I'm going to assume smaller burr sets are not necessarily inferior to larger burr sets, as long as the burrs were housed in a well made grinder.

There is certainly a relation between conical burr size and taste, but it isn't necessarily linear.

For some evidence of this, check out the lido2 beta testing thread, where the consensus was that, although that grinder is very precisely made and sturdy in use, its 40mm conical burr set does not match the clarity and flavor separation of a Titan conical when grinding for espresso. I have done some blind testing to confirm similar results between a few very well aligned and maintained vintage hand grinders and my HG-one. Contrast those observations with the HG-one user experience thread, in which users could detect no difference in taste between units equipped with 71 vs. 83mm burrs. I don't know how much of this testing was blind, but if there is strong interest in blind testing users of this site have obliged in the past. You just need to specify which specific grinders you would like compared, and then find out if someone with access to both has the time and energy to do the comparisons for you.

Of course, the caveat to all this is that not all palettes are alike. A difference detectable to one person might not be detectable by another. Likewise, even where there is consensus on a difference, there is still room to disagree about what tastes best. Since the ultimate goal is satisfying your own preferences, the best approach is to try as many grinders for yourself as you can, and then choose the one that suits you best.

Hey CN!

I think the HG One example highlights a better controlled comparison, i.e. the same grinder with difference burr sets. If there were also HG one's with 60 / 50 / 40mm burrs would the results be the same?

I think the best example of a quality espresso grinder with smaller burrs (and one I'm interested in) would probably be the portaspresso rosco grinder. I have see some comparisons between that and the Pharos, with varying opinions.

It's an interesting discussion...and a great excuse to buy more stuff

I haven't played with a Rosco grinder, so I can't make the comparison myself. I'd be surprised if it was more sturdily built or better aligned than my Lido2, which produces some of the most uniform grind output I have ever seen.

Here's a post by someone who did a side-by-side comparison of the Rosco with a Pharos (as well as a Lido1), and thought the Pharos did a better job for espresso: Hand Grinder Showdown! Pharos - LIDO - Rosco

As to subjective/objective & blind testing: Subjective experience is the goal we are trying to maximize when making espresso, so reliable subjective reports are ultimately more informative than objective measurements in this arena. Yes, blind tests screen out some potential bias, and thus are the gold standard, but non-blinded tests are still evidence, just slightly weaker evidence. Some differences between grinders are so clear that blinding makes no difference; it is most important for close cases.

I doubt you'll get very far with "explanations involving math," but this site is full of smart folks with eclectic skill sets, so maybe someone will show up and surprise us.

I also saw this one: Hand Grinder Roadshow with the pharos vs lido vs porlex. There are some posts I've come across on other sites with the Pharos vs. Rosco with it going either way, coming down to personal preference.

Because of my general curiosity I'm just wondering how/why a larger burr set would make a difference, all other aspects of the grinder being equal. The problem is all other aspects of the grinders are not equal and not all other variables involved in making the shot are equal, which makes comparisons tricky. It seems like it would be minimal or even preferential, at least given what I've been looking at, instead of big burrs being better just because they're bigger. It appears larger burrs might make a grinder more consistent which would make it inherently better.

As far as testing goes, a larger sample of microscopic analysis would be interesting. Although that seems to be prohibitively expensive. Or a large sample size blind taste testing prepared by single professional barista using various grinder could also be fun and useful. But, blind tasting multiple shots is also tricky as noted previously.

Unfortunately I keep coming to the same conclusion, buying more stuff and trying for myself!