Psyd wrote:To Ike's credit, this was never going to be a successful test. He suggested that if you grind finer, a tamp could be omitted from your regime. Tamping compresses a coarser grind to provide a firmer resistance to water flow. Not tamping would, well, not restrict that flow, and something else would have to replace it.
For your experiment to tell you anything at all, try grinding finer until a simple 'get these grounds below the dispersion block' tamp (as if you were simply giving it a bit of a mash on the plasti-crap tamp attached to the doser of the grinder) provides you with a 25 to 30 second 1.5 to 2 oz.
Then tell us what you think! ; >

Indeed. The grind wasn't specified during the original presentation; the finer grind hadn't been brought up until the 2nd page. Just simply missed it.

You're suggesting using a tamp to get the grinds below the screen which wasn't part of the original experiment and the grinds were noted to be at the rim of the basket as well. The idea was no tamping at all; however, for the sake of science, I'll try a super fine grind and an uber light tamp to see how I like the shot in comparison to what I'm getting now.

I have previously been an advocate here on H-B for a very light tamp on lever machines. Definitely under 5 pounds.

I consider my advocacy anti-proselytizing because the 30# tamp is the one true religion and those who swear by a precise ritual with nutating motions in the direction of the four corners of the world are the real proselytizers.

In my experience, a light tamp (or even no tamp whatsoever) hasn't led to channeling. If the (fresh and properly ground) coffee has been allowed to swell under hydrostatic pressure during a gentle 2-3 bar preinfusion, it will present (uniform) resistance to the water, and that (uniform) resistance from the swelling is the best charm against channeling.

Regards
T

P.S. Adjust your dose and grind to the roast at hand. Caffe DArte Firenze won't be the same as The Boss blend from Barefoot.

Hi everyone,

I would say that it's not that important, definitely at the end of the list of things to worry about when making espresso. I tried not tamping a couple of times and had a couple of nice shots, nothing very different from the stuff I get when tamping (I use a light tamp just to level the coffee in the basket). Still I decided to keep tamping because when not doing so I get a big mess on the shower screen and around the gasket and it's a PITA to clean it everytime.

I'm curious whether wetting during preinfusion on an untamped shot goes deeper than with a tamped puck? There's less resistance on the surface of the puck in the untamped shot as it's already touching the screen when locking the PF in and in my opinion water can go a bit deeper than on an untamped shot. Maybe a picture-compare can be made of tamped and untamped pucks right after the preinfusion phase? The other thing that makes me wonder is whether fines are locked in place a bit better when tamping? I would say that with untamped shots fines should migrate to the bottom of the basket a bit faster (at least the ones sitting in the upper layers of the puck) which would result in a slightly slower midpour. This might not be true however as you still need to grind finer to get a proper shot.

Regards,
dsc.

OK, reporting back on my experiment. Ground finer; 16gram in a ridgeless double; still did wdt and leveled; tamped 5-10lbs (couldn't say for sure, but definitely less than 10). Probably ground too fine as it resulted in a pretty tight ristretto. Just over an oz in 35sec. Visually from the NPF, it looked terrible with several "dead" spots and started out as a donut extraction (albeit very very slight). Still messier than a normal double with my tamping routine, but far less messy than no tamp at all.

Taste: probably one of the better tasting ristrettos I've pulled. Super chocolatey! Seemed to have more crema as well, but can't say with absolute certainty.

I'm going to mess around with some more grind and a light tamp, but I will say I'm a little surprised. What really gets me is how little effect the tamping has on the flow rate.

cafeIKE wrote:Rocky Roaster Organic Espresso 3 days post roast.

I have no idea what's in the blend.

Would be helpful to know what was in it.

The only times I've seen anything close to repeatable quality results with no tamp has been with the combination of a coffee that is very high in natural processed and/or aged coffee, and often has robusta - with a very fine grind plus light dose - and a machine that doesn't have the quick ramp up of pressure of a stock LM Linea (for example).

It's entirely possible that it could work now and then, regardless -- but doing so in a manner that create repeatable flavour and quality is a different matter. And it's then that the above combination seems to be the one that is most common.

Given this - I'd love to know if there are other combinations that also give users the option of getting repeatable results with no tamp.

I think Ian's tamp/no tamp experiment is being taken too literally, as a tamp/no tamp dichotomy. His procedure, in my mind, reveals a more important and interesting question. It is not whether we should tamp at all, but whether or not a precise bathroom-scale-tested tamp is really necessary. Home baristas have, since the very beginning of the home barista trend, debated how hard one should tamp - 30 lbs.? 40 lbs.? - giving only hypothetical justification for whatever number they see fit for their espresso ritual. The matter now, as I understand it, is not quantificational, but rather a question of necessity...

Let's do some math. Let's assume that the diameter of the surface of your espresso puck is 58mm. It probably isn't, but it's close to it in reality. The surface area of that puck, converted to imperial measure, is then 4.1 in., approximately. At 9 bar, ~130 PSI, you have a 533 pound water hammer striking the puck. Even at 4 bar preinfusion, 68 pounds of force strikes the surface of the puck. This is assuming that the pressure applied by the water actually compacts the puck. This is still a matter of debate, but you can very easily observe that cake compaction occurs in an Aeropress, even at pressure just above 1 bar. Essentially, whatever pressure is applied by the tamp is surpassed by the action of the pump and renders it irrelevant.

This doesn't mean that any tamping is irrelevant, but in a way reinforces the importance of a well executed tamp, at whatever pressure, that produces a cake of coffee that is consistent throughout and able to withstand the violence of that 533 lb. water hammer.

With regards to no tamp at all, it's pretty clear how a long and gentle preinfusion time, which is common in Italy, benefits cake compaction.

timo888 wrote: If the (fresh and properly ground) coffee has been allowed to swell under hydrostatic pressure during a gentle 2-3 bar preinfusion, it will present (uniform) resistance to the water, and that (uniform) resistance from the swelling is the best charm against channeling.

All well and good if we all have access to that sort of thing, but some Silvia users are going to have issues generating a gentle 2-3 bar pre-infusion. Heck, it'd be trick on my commercial machine as well!
No one is saying that nutating motions, WDT, facing east, 30 lbs. or even tamping, is necessary, per-se, but possibly a solution for a machine that isn't providing adequate results at the moment*. And 30 lbs. isn't even a magic number, but it is something that has been working reliably, across a number of platforms, is easily and safely reproduced across a lot of different human physical types, and is easily communicated. The suggestion here with the clicker or bathroom scale training is to learn to be consistent. Consistency in all of the preparation techniques will more readily identify where potential failures in equipment or technique will rear their ugly heads.
None of these things are magical or be-all end-all solutions. They are temporary fixes to stave of the inability to upgrade around the problems, quite often, and they are also consistent techniques, that, while not guaranteeing great results, can reliably be depended upon to generate good and dependable results. Which is where you want to be before you start changing variables to chase the elusive (fill in appropriate deity's name here) shots.
Nothing wrong with not tamping, nothing wrong with not nutating, and nothing wrong with not WDT'ing. You know, unless, of course, the problems that went away when you started doing those things suddenly return.
On my truck, to open the door you have to push the door closed with your thumb while lifting the handle, and you have to hold the handle up when you lock it. I'd never suggest that these things should be done on all vehicles. But, I'd still tell the guy that suggests that I don't have to hold the handle up for the door to lock to go away and leave me alone, 'cause I know better. And the guy that came here asking why his door won't lock when he shuts it? I'd probably suggest that he try to hold the handle up. If it works, I'd have a hard time not arguing with the cat that insists that it isn't necessary.

*Of course, after all the usual suspects are eliminated; old coffee, bad grinder, improperly functioning machine, etc.

Psyd wrote:No one is saying...

Beg to differ. The internet espresso fora are littered with prescriptions of "proper 30# tamp", "zero force lift off polish", "gentle NESW, then full pressure", "remove tamper quickly" ad nauseum as remedy without any equipment specificity.

The hand ballet in the typical "Critique My Technique" thread gives ample witness to the prevalent impression of what's "necessary" to pull a decent shot. The no tamp shot and puck are evidence in support of a simpler regimen.

Psyd wrote:On my truck, to open the door you have to push the door closed with your thumb while lifting the handle, and you have to hold the handle up when you lock it.

A learner with exposure only to keyless operation might assume the door procedure is a nervous tick, akin to Nomar's glove fidgeting. It doesn't make him hit any better, but sure annoys the pitcher.

Regarding the truck, the burrs are shot. I'm calling the sheriff.

Been playing around w/ the no/light tamp for a couple more days with 2 different roasts. No tamps and super light tamps (5lbs or less) are messy and don't seem to be consistent. I was hard pressed to tell much difference between a 20lb tamp and a 40lb tamp that I normally do. What I found interesting is that with a 10(ish)lb tamp, I could actually taste a difference in both of the roasts. Roast "a" was noticable sweeter and a little more fuity. Roast "b" there was less difference than in roast "a", but I would have to say sweeter and a more balanced flavor profile. My espresso taste buds still have there training wheels on, but I would definitely say there was a difference and I prefered the lighter tamped shots compared to what I would normally pull even though they weren't night and day differences.

It may not necessarily be the actual tamping pressure, but it could be HOW it's tamped. Going with a far lighter tamp than what I have been doing, I was being extra careful. It could be the finer grind itself and have NOTHING to do with the tamping. Since the no tamps didn't fare well for me, I'd argue that tamping probably makes a difference.

I can't recall who or when (I think it was about 2 or 3 years ago... +/-) someone on alt.coffee (Andy? Greg? Jim? ?) did a test with tamping force. I think that the results showed that anything over about 10 pounds and under about 60 (iirc) resulted in about the same pull. I am not sure about the specific numbers, but the interesting thing was that 35 pounds was right in the middle of the range.

As a new home barista some 8 years ago I followed the advice that was, indeed, all over and came from almost every source concerning tamping force, and gave that same advice to lots of folks as well. I haven't worried about tamping force since I read the results of that test.

IMO, the main benefits of tamping, GENERALLY speaking, are that it keeps the coffee off the shower screen during the pull, compensates for uneven distribution, levels the coffee so there are no think or thin areas, and breaks up clumping. For the last year I have paid a lot more attention to distribution and dose and a lot less to tamping and have enjoyed very fine coffee.

Some advocate a tamp with not much more than the weight of the tamper, and others still use a "handstand tamp" where if your feet are still on the floor you aren't doing it right. I think a tamp is important, but put it low on the list of things to do to make espresso. The quality of the grinder and its output has a LOT more to do with it. A grinder that produces a grind that is clumpless and in a commercial environment a doser that can accurately dose and distribute the coffee evenly is far more important. I assume that is why the cafes in italy just click click and tamp against the tamping-nub on the bottom of the doser and have at it. It's not that the tamping is less important, it is that the grinder is more important and I think that is a point that is lost quite often in this discussion. The two can't be separated. Going from a Rocky to a Kony taught me that in a big way!