Dose and yield -- how do I go from good to great in espresso tuning?

[aehernandez]

Over the past few months I've been honing my espresso tuning process to get it to specialty cafe levels of great. I'm in a good place, but I want to start getting better.

First, I want to understand some contradictory guidance I've seen around dose. Espresso 101: How to Adjust Dose and Grind Setting by Taste recommends adjusting grind size and dose together to achieve balance while maintaining the same dose. On the other hand, Barista Hustle and James Hoffman both recommend keeping dose a constant through the tuning process. I use an 18g VST basket, and in my small trials I've found that messing with dose really mostly gives me inconsistent results -- I struggle to find the balance of changing dose and grind to get the same flow rate.

Currently my process for tuning espresso to make adjustments on my grinder, going finer if want less acid from my coffee and coarser if I want less astringency / bitterness in the finish and I'm okay with more acid. I may increase my yield if I want a less aggressive coffee, or lower it if I want a fuller body in the cup. Rarely, will I touch temperature (unless I'm working with a super light roast, otherwise I keep it at 200F) and I haven't really understood the effect of changing dose, so I stay away from it. Given that I keep the rest of my process the same (let my machine come to temperature over 30 min, flush regularly, use a distributer and palm tamper for puck prep to promote even extraction, use the ten second infusion that's default on my machine) that leaves me with two variables: grind size and yield. Do I need more than that? Even after three or four shots of messing with those variables I still feel like I'm leaving coffee goodness on the table based on what I was able to get at a cafe.

Here's my equipment:
- Breville Dual Boiler
- Niche Zero (I usually grind in the 14-19 tic range)
- Crema distributer and palm tamper
- I use distilled water and add third wave, espresso profile
- Beans are from a local roaster, my best results have been from medium and medium-darks roasts.

Process-wise:
- Dose is 18g in a VST basket
- I typically target 1:2 yield, so 18g in and 36g out, though I may play and go up to 40g out
- Machine is set to 200F
- Distributer + palm tamper
- I look for a steady, thin stream going out, usually hitting between 9-10 bars of pressure on the gauge
- Extraction time (including the 10 second pre-infusion that's default in the BDB) is typically within 22-40 seconds, though I really shoot for 30 seconds.

Does anything stand out to you as problematic? Is there any way I can improve my current process?

[Jeff]

36 g in 25 seconds

Finer if too sour, coarser if too bitter

Keep your hands on the car's steering wheel at 10 and 2

(I guess it's 9 and 3 now)

All are examples of the general guidance you can give someone to start learning a new skill, that, in everyday practice, are regularly broken.

The thing I found most valuable was keeping notes of what worked for me, my coffees, my grinder, my machine, and my tastes. I'd note coffee origin (or blend) and rough roast level when I changed bags. For every shot, I'd write down dose, grind setting, yield (grams in cup), and time, along with a simple description of overall flavor balance. Nothing fancy, "yuck, really bitter" or "dirty flavors" or "good". Every line had what changed from the previous circled to make it easy to see. After a while, it became sort of a second sense that if it was "really bitter" I probably needed to go two marks coarser (for that specific gear). After a while, you start "breaking the rules" because you've been there before and your experience gives you a good guess as to which changes to make.

One thing that I'd add to your collection of "tricks" is for darker roasts. These might be an occasional medium, some medium-darks as well as many darks (to me, visually "dark" means any sheen or droplets of oil on the beans). If you're getting too much roast bitterness and it goes too acidic if you loosen the grind, you might try cutting the shot before you get to the point of blonding, without changing the grind. It's one of those things you can explore and get a feel about with time. No magic rules, though typically not an approach for medium and lighter roasts.

[aehernandez (original poster)]

Thanks for the reply Jeff! I've also gotten into the practice of keeping a log, mostly to remind myself of where my "good" settings where as I explore the variables.

Do you ever change more than your grind size and yield based on taste? Its unclear to me when I'd change dose over grind size.

[crwper]

Do you ever change more than your grind size and yield based on taste? Its unclear to me when I'd change dose over grind size.

I'm pretty new to all this myself, but a couple of things come to mind with regard to changing dose rather than grind size.

First, at some point, if you're grinding finer to increase extraction, you hit a point where thing become unstable, with channels forming some of the time and inconsistent results. At that point, I think you would be better off increasing dose rather than grinding finer.

Second, thinking about the thickness of the tamped puck, there is always a gradient in extraction level from the top of the puck to the bottom, with particles at the top of the bed more extracted than those at the bottom. So increasing dose, I would expect not just a slower flow and greater extraction, but also a broader extraction profile. However, I'm not sure how much difference this makes in taste, e.g., going from 18 g to 20 g.

[Jeff]

Those are the two that I generally get the most change in flavor from. I tend to stick with one dose. With classic roasts I'd usually dose 18 g or sometimes 20 g, depending on the coffee and my preferences of the month. Some of those just were "too powerful" at 20 g, or "too thin" at 18 g. It would be a decision I'd make after dialing it in at one dose and then maybe trying to see if it was a little better at the other dose.

I'll very, very occasionally change dose by 0.2 or 0.5 gram or so rather than trying to "bump" the grinder a fraction of a mark. It was more often that I did that with the Compak K10 shop grinder, as it didn't adjust as smoothly as a Niche Zero. With the Niche Zero, I can't remember the last time I did that with a standard profile*.

Light-roast espresso is almost a different drink. Many who enjoy it forgo creamy mouthfeel for delicate flavors. With light roasts, I tend to dose around 17 g, with my current machine, baskets, grinders, and water.


* The DE1 has some "unique" profiles that can be very, very sensitive to grind size, as they are constant-flow, rather than constant-pressure.

[cafeIKE]

I make micro changes all the time.
With Land & Water Discovery Espresso

IMS double basket, ≈195°F, 8.5bar

Original:
Niche pos 12.7¹, 16.7g, 30s², ≈32g, cool about 1 minute

Now:
Niche pos 12.8, 16.5g, 25s, ≈30g, no WDT, cool about 1 minute

The shot is more balanced and rounder. When cold³, the original prep was a bit acidic and 'perk coffee'. The new prep when cold is like a Terry's Milk Chocolate Orange without the sugar wrapped in the best Madagascar unsweetened dark chocolate.

The point being: Make Haste Slowly

1. as close as "damn it all" is to swearing. I'd tried a gifted ABUDE and the Niche is not 110% repeatable like a geared unit.
2. from first drop
3. room temp

[Rice Bowl]

I had a lot of success following something like the coffee and espresso compasses from Baristahustle. Again, a rudimentary guide that helps you make ballpark changes in order to dial in your brews/espresso to your preferences. Taste is going to be king as far as judging which direction to go.

[PeetsFan]

You seem to be doing everything perfectly. What are your taste buds telling you? You might want to go to a few of the best cafes you can find and order an espresso or macchiato, and see how they taste. That's what I do, especially when traveling. I think you probably can't improve results without being lead by taste.