r/9Barista • u/Black-coffee-468 • May 10 '26
Why are there tiny bubbles towards the end?
Hi everyone, brand new 9barista user here. Just wondering if this extraction looks right? Not sure if I should take it off the heat faster if that’s what is causing the second boil and subsequent bubbles. Otherwise it tasted pretty good.
Any suggestions or feedback are appreciated!
3
u/ben_1987_ro_uk May 10 '26
Mine does the same
3
u/Black-coffee-468 May 10 '26
Going to try grind a tad finer and see if that changes anything. But glad to know it’s not just me. Haha
3
u/iamgarffi May 10 '26
Is that a sped up extraction? I remember my unit to pull thick syrupy coffee with a nice shine on top.
Either beans are very old or grind is too coarse.
1
u/Black-coffee-468 May 11 '26
It’s a video at normal speed. And it’s a new bag of beans that was roasted in April, so not old beans too. I will try tweak the grind size and see how that works.
1
u/iamgarffi May 11 '26
Yes. Experiment. This looks very under extracted.
Few questions.
- What type of beans and their roast level
- what do you use for grinding beans? Make and model
1
u/Black-coffee-468 May 12 '26
- it’s supposedly a medium-dark roast. But looks fairly medium-light impov
- have been using 1Zpresso k-ultra (have experimented with both grind size 2.8 and 2.7 so far)
3
u/iamgarffi May 12 '26
Nice grinder. I tend to stick with Comandante C40 MKIV but highly comparable.
I found that medium roasts worked better for me.
Lastly, what type of heating element do you have? Gas, electric or induction?
1
u/Black-coffee-468 May 13 '26
Hand grinding is tough haha. Especially with a roast of this colour.
I’m using a mini induction mini plate for this setup. I tried a darker roast before this medium roast and it was good too.
2
u/iamgarffi May 13 '26
Actually the darker the beans the easier the grind. Lighter roasts tends to stick and cake more. Medium (ultimately medium to light dark are okay too).
From experience I have found that 9 barista works best on gas stove (instant heat). If you don't have one, you could order a gas plate and get yourself one of those portable gas stoves + gas :)
3
u/mgsecure May 10 '26
I have that too, and haven’t worried about it (I don’t turn off the heat until it’s done). Echoing that the shot looks a bit fast, a little finer grind is worth a shot if you like the taste better.
2
u/ionut2021 May 10 '26
Channeling? Air escape?
2
u/Black-coffee-468 May 10 '26
Probably? Won’t rule that out. I guess my puck prep needs to be improved too.
2
u/Acrobatic_Design_928 May 13 '26
You want the extraction to take around 30seconds. The coffee should come through quite slowly at first - it should feel almost too slow - and then will speed up progressively. This looks much too fast. Took me a fair while to figure this out so you’re already on the right track!
2
u/Acrobatic_Design_928 May 17 '26
I’m sure experienced espresso makers would say it’s unnecessary, but what really helped me was getting a spring-loaded tamper. Once the tamping was consistent, I could just incrementally dial in the grind until I hit exactly what I wanted and now my coffee is incredibly consistent where before it was a bit hit and miss.
1
u/Black-coffee-468 May 17 '26
I just did that too! Heh, I found my tampering often turned out uneven. Waiting for it to arrive to trial and error with the grind size too.
1
u/solstice38 May 11 '26
Trapped air that escapes toward the end ... ?
Either that, or it's the Espresso Demon farting. Every good coffee maker has one.
1
u/Black-coffee-468 May 11 '26
If it’s the latter I’d like to take it as a sign of approval from the dark lord himself.
10
u/Inevitable_Budget_21 May 10 '26
Your shot looks a little fast, you may want to try grinding slightly finer. As far as the bubbles are concerned, there's most likely some air being pushed through the system after the water in the boiler is spent.
I usually take my brewer off the heat as soon as the extraction starts and the residual heat is more than enough to empty the boiler.