Coffee Data Science
Staccato Espresso Preparation Tips
A collection of tips that have helped me layer espresso
When staccato espresso came about three years ago, there was no prior knowledge. There wasn’t much to inform how to sift, how to debug, and how to optimize layered shots. I spent the past few years experimenting to gain a deeper understanding. I present these tips in hopes that you are able to better pull a staccato shot.
The aim for staccato is that you should dial in a grind for a regular shot, and then make a staccato shot with that grind.
When to know your coffee is fully sifted
This is absolutely the most important part of sifting. If your coffee isn’t fully or mostly sifted, you will encounter other issues with this technique. Your bottom layer won’t slow the flow enough and your top layer will channel too much.
To know if the coffee is sifted full, sift for 1 minute at a time, and weigh the bottom tray. When the weight stops increasing, it is fully sifted. Typically, for 300um/400um screens in the Kruve sifter, it takes me 5 minutes to fully sift 20g of coffee with an agitator on top of both sieves. Without the agitator, it takes about 8 minutes.
The trick is to pick the right sieves. If you are using mesh interlaced screens, you have to be aware that squares have to be measured by their diagonal otherwise you could be greatly off.
If you use a Kruve sifter, it will give you the more fine control between the screens.
Number of Layers
More layers has potential, but beyond 3 layers is mostly unstudied. I like two or three layers, and here is what I would suggest.
2-layer preparation should use a sieve that cuts the grind in half. Typically, I use a 300um sieve for setting 13 on the Niche. That all depends on what you are dialed in at and your coffee roast.
There is a difference between the sieves in the original kickstarter for Kruve where the 400um of the original is very similar to the 300um of the new sieves in terms of how it functions. So experiment and try different sieves.
3-layer preparation should use 1 screen that gets nearly half (typically 300um or 400um), and then another screen to split the rest in half (typically 400um or 500um). Some times the coarse layer has little in it.
Higher End Grinder: a lot of higher end grinders have a tighter grind distribution. This means that 2-layers might be more practical than 3 or one might use their grinder to make sudo-staccato and not use sifting at all to layer.
I would recommend adding an agitator to a sifter. For >500um, an agitator isn’t necessary. For >200um, an agitator will cut the sift time in half. For 200um, at least for the Kruve sieve, you need a spoon or spatula to push the grounds through.
I have tried a metal disk and paper. Metal disks are loud. Paper has the advantages of not being as loud, but they wear out over time. Paper seems to help the coffee fines separate.
I suggest using a paper agitator by putting a few coins (for weight) inside a folded triangle from a full sheet of paper.
Staccato shots take up less volume because the particle sizes are more homogenous per layer. So I typically have to increase my dosage by 1 or 2 grams to get a similar amount of headspace.
A small headspace is key to a syrupy shot.
Distribution tools haven’t been made for staccato, but that’s okay. Using a flat piece of plastic or metal will work or a toothpick to move everything around to make sure the bed is flat.
Tamping should be done with care. The bottom layer should be tamped very lightly. I usually put the basket on a scale, and I tamp to 300g.
For 3 layers, the middle tamp is only to flatten everything (just touching the grounds).
For the top layer, again, a light tamp should be used. I usually use a auto-leveling tamper.
I already use a longer pre-infusion (PI) for my shots, approaching 30 seconds. This is especially key for staccato. I use two metrics to determine when to end pre-infusion:
Time to Cover the Filter (TCF): This is the time it takes at the beginning of the shot for the filter to be covered with coffee. I’ve previously shown this to be a good predictor of when to end pre-infusion at 3*TCF. So if TCF is 5 seconds, 15 seconds is a good pre-infusion time.
Time to 10ml (T10): Some times, shots run very fast, so 3*TCF is not practical. I also look at my shot glass which has a marking for 10ml. You could also use a scale and look for the time to get to 10g of output. This time is a good time to stop PI.
A good shot will have a TCF around 10 seconds and a T10 of around 25 to 30 seconds.
The main key for infusion is to end the shot when it start blonding. You need to end it earlier than normal because staccato shots extract at a faster rate per volume. Typically, a 1:1 (output to input) staccato will have a similar coffee extraction yield as a 2:1 regular shot. So if you pull a 2:1 staccato shot, you’re risking over-extraction.
Output Yield: I would suggest starting at 1.5:1. So for 20g in, 30g out. Then adjust based on taste and mouthfeel.
Pressure: I would recommend lower pressures like 6 bars or pressure profiling, controlling for constant flow. Ultimately, I pressure pulse because I have a lever machine, but if you can’t do that, try some lower pressures than 9 bars.
I am a fan of letting a shot rest for a few minutes (typically 4) where the beverage cools to around 47C. I find it is easier to taste it.
The staccato shot, in my opinion, is the most advanced shot in terms of taste, extraction, and texture. I have tried my best to pull learnings from sifted, layered shots (staccato) to regular espresso shots, but there is still a gap. I hope these tips help you pull better staccato shots or maybe some of these tips will help with your regular espresso shots too.
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