How Important Is It To Use a Leveler Before Tamping Your Espresso?
Anyone who knows me will know, I like coffee. And not just coffee, but the process of making coffee. I’m the nerd who likes to spend five minutes making a shot of espresso because I enjoy the journey as much as the destination. Getting into a flow state where you lose yourself to the process, it’s a form of meditation I find rewarding. But I also value efficiency and economy of motion. I may not mind spending five minutes, but I want every second of that five minutes to be adding something to the quality in the cup. To that end, I’ve tested a lot of toys. Spray bottles, embroidery needles, canning funnels, grounds sifters--they’ve all made cameos. Some stick around for a while, others… not so much. In the latter camp are the coffee levelers, much to my dismay. There’s something just so alluring about rendering a disheveled mess of coffee in the portafilter into a perfectly level, smooth surface with just a few, easy twists. But looks can be deceiving and I found that the smooth surface lulled me into a sense of complacency. I was finding that I was still seeing more inconsistency than I was aiming for, and I just knew that I could do better on the taste of the espresso itself.
In an ideal world, a leveling tamper would work by distributing grounds in the portafilter evenly while then applying a tamping force. It is supposed that the leveler will do a better job of distributing these grounds than would a person since it can achieve a degree of mechanical precision that a human can’t match. Since it uses the rim of the portafilter as a reference point, it would also be exactly the same each and every time. I have some problems with these claims.
Compared to other common distribution techniques baristas will be familiar with (such as John Weiss’ Distribution Technique, Matt Perger’s Holdswirl Technique, or Scott Rao’s Vertical Tapping Technique), a leveler really only affects the very top layer of the puck, leaving the bulk of the coffee in the portafilter to its own devices. And if we can all agree about the importance of puck preparation, does it not also follow that we should try to prepare all of the coffee instead of some small percentage of it? It’s hard to conclusively point fingers at any one part of a complex system, but my gut tells me that this was the source of the inconsistency and channeling I was seeing.
My next point of contention lies with the tamping action itself. Since leveling tampers like the OCD tamp at a prescribed height relative to the top of the portafilter instead of tamping to a consistent pressure as is traditionally advised, any variance in the dose size will result in a difference in tamping pressure exerted on the bed of coffee. Though there is little evidence to show that the specific tamping pressure matters in terms of overall extraction of coffee (This paper by Socratic Coffee suggests that it is responsible for only 3.3% of extraction variability), there is still theoretically a lower limit to what tamping pressure ought to be used. On the reverse side, coffee can only be tamped so hard before it cannot be compacted any further. Practically speaking, this means that you have a window within an upper and lower height setting on a leveling tamper that you have to work within for any given dose setting. Too low and you’re not tamping, too high, and the tamper can’t touch the edges of the portafilter and won’t make an even bed of coffee. In my (admittedly anecdotal) experience, this could be sometimes finicky to set, especially if you often switch between coffees that necessitate a different dose as I do, since it means that you’ll be setting the height on the tamper frequently.
As I’ve stated before, I don’t particularly mind extra effort if there is something to be gained through it. So I can avoid the inadequate distribution of a leveling tamper by making an initial pass of distribution. I can excuse the extra effort required of setting the tamper height whenever I change coffees. All I ask is that I get something in return for it. The only problem is, I wasn’t finding that pay-off. In trying to find out why I found another article by Socratic Coffee which specifically tested a reputable leveling tamper. Their findings indicated that the leveling tamper did not make shots any more or less consistent than a common tamper, but that it did lead to lower extractions. An argument could be made that TDS doesn’t matter since it can only tell you how much of the coffee you’re extracting, not what parts of it. And I agree, to an extent. After all, I’ve had some pretty terrible shots that had high extractions. All the same, a larger chunk of the better shots of espresso that I’ve had in my life have been shots pulled at higher extractions. Even Scott Rao himself attests that “A technique that produces higher extractions for a particular brewing method will usually yield better results than will lower-yielding techniques.”
I’m not going to say that there aren’t any levelers or leveling tampers out there that don’t do a good job, just that none of the ones I’ve tested have improved upon a conventional tamp. And until I, or any of my friends and coworkers here at Chris’ Coffee, find one that we think is good enough for you, the customer, that we don’t intend to sell them for the reasons stated above.
Only the best for you.