Again in February, Lance Hedrick confirmed the world that shaking your grounds earlier than making an espresso might each enhance the extraction and scale back the shot time of your espresso. The impact on extraction was placing, nevertheless it was the truth that it additionally decreased shot time that actually fascinated us. That discovering implied that shaking might allow you to grind finer with out inflicting clogging, doubtlessly permitting increased extractions with out unfavorable flavours creeping in.
Just some months later, shaking appeared on the World Barista Championship, when Dominika Piotrowska, representing Austria, used shaking on stage for her routine. Domenika defined to us this week one very tangible profit from shaking grinds:
“One vital discovering was the outstanding consistency I achieved in extraction time. The distinction between pictures was solely 0.1 seconds every time (e.g., 20.0/20.1, 20.0/20.1). This degree of consistency was unprecedented for me.”
Dominika Piotrowksa dosing into blind shakers on the 2024 World Barista Championship.
Our personal testing, alternatively, gave contradictory outcomes. Shaking appeared to work in some conditions and never others, and we by no means noticed the mix of elevated extraction and decreased shot time that made shaking so thrilling. In some sense, that is what we anticipated: in our first submit on the subject, we explored the potential causes that shaking would possibly work, and concluded that “the ‘finest’ distribution technique total will rely on the grinder, the roast, even the ambient situations.”
This matter has opened many new doorways for espresso making, however weirdly — nobody can fairly work out why it really works … and typically doesn’t work in the best way you’d count on. Sure, we anticipated shaking to work higher in some conditions than others, however we needed to know why it labored for Lance, and never so nicely for us. Does it rely on the espresso, or the grinder? Or one thing else solely?
In our earlier posts, we explored ‘densification’ — the concept fines would mix with bigger particles to create extra spherical aggregates. Whereas we nonetheless don’t have a whole reply, after some new testing this week, what we now have seen means that this isn’t taking place. In truth, we see the other:
The Shaking within the Basket Check
On our travels, we’ve seen fairly a couple of baristas beginning to shake instantly within the filter basket, while holding a dosing cup on the highest like a lid. So we needed to check the efficacy of that method in comparison with utilizing a function constructed shaker. We had a principle that probably lots of fines might be sieved by way of the holes within the backside of the basket while shaking and we needed to search out out if that was an issue, or if it could have an effect on extraction yields. However within the technique of testing this, we appear to have come across one thing fairly much more fascinating.
This week our Dean of Research, Jem Challender teamed up with Lloyd Meadows from Tortoise Espresso to check shaking utilizing a Mythos grinder and a Synesso and located that shaking made little or no distinction in extraction or shot time with one espresso, and barely elevated each extraction and shot time with one other. None of those outcomes confirmed a statistically vital impact, however they’re a minimum of per the concept which espresso you employ might have an effect on how nicely shaking works.
We then repeated the exams with the identical espresso used within the second check, however utilizing an EK43 as an alternative. This time, shaking appeared to extend extraction, though the distinction was not statistically vital (p ~ 0.1). It did nevertheless lower the shot time by a few seconds, and that distinction was vital (p < 0.05).
| No shake | Shake | |
| Mythos check 1 | ||
| Extraction (%) | 20.1 | 20 |
| Shot time (s) | 21.6 | 20.6 |
| Mythos check 2 | ||
| Extraction (%) | 20.5 | 21.3 |
| Shot time (s) | 28 | 30.3 |
| EK43 | ||
| Extraction (%) | 21.4 | 22.4 |
| Shot time (s) | 21.8 | 20 |
Extraction yields and shot time averages for shaking vs not shaking. Outcomes are a median of 5 pictures per check. In every check, we distributed the espresso utilizing the AutoComb. The espresso we used was a Colombian, Reinaldo Parra ‘Las Pinas’ Washed Espresso.
These outcomes counsel that the selection of grinder can also be a part of the rationale that shaking works higher in some exams than others. In our final submit we noticed that the grinders that Lance used for his exams (the EG-1 and DF64) each produce much less fines than different single-dosing grinders, which might clarify why his outcomes have been so totally different to ours.
If it’s the behaviour of fines that decide how shaking works, then it’s no shock that the impact is totally different with totally different coffees and grinders, and even in several places. The quantity of fines you get whereas grinding will depend on the espresso and the grinder — in addition to many different elements, together with temperature, the moisture content material of the beans, the situation and alignment of your burrs. This alone can clarify why we get totally different outcomes than Lance, and even totally different outcomes from one check to the following.
Free Your Fines
However what’s it that fines are doing after we shake the grounds? You keep in mind early on within the shaking dialogue, espresso researcher and roaster Dr Mark Al-Shemmeri, theorised that shaking might have an impact much like ‘densification’; a course of utilized in industrial roasteries when packing pre-ground espresso. A densifier is actually a big mixer, and the blending course of smooths out the jagged edges of bigger espresso particles, and forces fines to lodge inside their pores. This produces aggregates that act like denser, extra spherical espresso particles and scale back the variety of free fines within the grounds.
When we tried measuring the particle dimension distribution of grounds after shaking, nevertheless, we discovered that the other was taking place. Utilizing Professor Abbott’s Grind Dimension Evaluation app, we noticed a rise within the variety of particles beneath 100µm after shaking.
However right here’s the place it will get fairly weird: Throughout our most up-to-date exams, when pulling pictures with shaken grounds, the portafilters appeared to get soiled extra shortly. Check out these pictures beneath. Every photograph exhibits the residue left behind on the underside of the portafilter after pulling only one shot. The portafilter was spotlessly clear previous to pulling every shot.
Shaking grounds releases fines from the espresso. The within of a portafilter after making one espresso exhibits the distinction that shaking makes. With out shaking (left), the portafilter nonetheless seems clear. After shaking in a dosing cup with the filter basket on prime (center) or with a blind basket (proper) much more fines and residue are seen.
We examined this a number of occasions, and every time the end result was the identical. Once we made a shot with out shaking, as seen on the left, a really small quantity of fines collected on the bottom of the portafilter as you’ll count on. Then we examined the impact after shaking for five seconds with a dosing cup inserted instantly on prime of the filter basket (center) — cocktail bartender fashion. To test that this impact wasn’t merely the results of fines escaping by way of the holes within the basket, we additionally tried shaking in the identical dosing cup however with a blind basket on prime. Shaking seems to extend the quantity of undissolved solids coming by way of the holes within the portafilter — and within the case of shaking within the filter basket the quantity of residue is dramatic. With each strategies the rise within the quantity of stable on the ground of the portafilter is clear, however we’re guessing that is solely a fraction of what’s being washed down into the cup beneath.
If shaking releases extra solids from the espresso mattress, maybe this additionally explains the flavour and tactile results we noticed in our earlier submit. Miruna Tudose and the workforce on the fabulous Origo Espresso in Bucharest reported a “considerably powdery texture, and an absence of readability” of their pictures after shaking the grounds.
Please notice, for the pictures above, we used an HE% basket from Pesado, which has fairly giant holes to permit excessive circulation. With that in thoughts, we additionally checked how a lot espresso escapes by way of the holes within the basket in case you actually go for it with the shaking. After 30 seconds of forceful shaking, we have been in a position to acquire round 0.1 g of espresso — not an enormous quantity, however maybe sufficient to impact how the shot runs.
To Shake or To not Shake?
On the finish of all these exams, our conclusion stays the identical: whether or not or not shaking will increase extraction and reduces shot time appears to range, relying in your espresso, your grinder, and plenty of different elements. It might be that shaking is extra useful if in case you have a high-end grinder, just like the EG-1.
In the event you’re going to shake, then it’s in all probability higher — and undoubtedly cleaner — to not shake instantly within the filter basket. A devoted device just like the Blind Shaker from Weber Workshops is in any case much more ergonomic than attempting to shake a heavy portafilter.
However whether or not you shake the espresso within the portafilter or in a devoted shaker, keep watch over your spouts. You would possibly discover it is advisable rinse the portafilter extra typically than ordinary to maintain the espresso tasting clear and candy over the course of an extended day’s espresso making.
Finally, the one strategy to know if shaking will be just right for you is to strive it out for your self for each espresso that you just serve, checking the impact on flavour in addition to extraction earlier than making a choice. However if in case you have the fitting setup, and the fitting espresso, to learn from shaking, it’s a marvel how efficient it may be.
Methodology
The Equipment We Used
- For these exams we used a Synesso Hydra.
- The preinfusion stress was operating 3 bar and pump stress was set to eight bar.
- We used Pesado HE% Baskets.
- The EK43 has titanium coated burrs.
- We used a Rhinowares chrome steel dosing cup.
- We tamped utilizing a Puqpress and distributed utilizing the AutoComb for all pictures.
- We didn’t faucet the basket vertically.
How We Shake
- For the ‘Shaking in Basket’ technique we dosed the espresso into the basket utilizing the dosing cup; left the dosing cup in place (the wrong way up above the basket) and shook the portafilter and dosing cup like a cocktail shaker for 18 shakes (5 seconds of shaking).
- For the ‘shaking out of basket’ technique, we positioned a blind basket on prime of the dosing cup to cease the espresso falling out and shook that like a cocktail shaker, additionally for 18 shakes. (That’s not a foul shaker hack in case you’re on a finances by the best way.)
- For the ‘No Shake’ technique we did all the pieces the identical because the aforementioned shaking strategies, simply no shake.
- Except for the three pics we’ve already proven you (above) we pulled one other three repetitions of every technique which you’ll see beneath.
Shaken out of basket
Shaken in basket
A Future Experiment
Seeing as there’s a distinction within the quantity of grinds sitting on the ground of the portafilter from these three approaches, there’s very more likely to be a distinction within the quantity of stable within the cup. So methods to check that? One concept we’ve had is to pour an espresso by way of a filter paper; look ahead to it to empty; then pour some extra water by way of the paper to rinse out the dissolved stable. After that, we would be capable to use a modified model of Prof Abbott’s grind evaluation app to depend the particles which might be trapped within the filter paper and measure their diameters.
