Coffee Machine: Breville Barista Pro with grinder Size 12
Bean: ALDI Lazzio Medium Dark.
Just found the coffee taste bitter in last 2 days, did not change any settings.
The espresso looks under-extracted, so I have adjust the grinder size to 13, to make the espresso ratio back around 1:2, but still bitter than before.
Would like to know if this is caused by the grinder or coffee bean?
Thanks for your comment mate, really helps solve my confusion as I just started making coffee 2 weeks.
How often do you clean the grinder and do you store the beans in an airtight container? And are you leaving the beans in the grinder hopper overnight?
A good point,
Haven’t clean the built in grinder yet, as just bought the machine 2 weeks only.
How often would u recommend to clean it?
Few things, never put more beans in the grinder than you are going to use now. Coffee ground will absorb moisture from the air very quickly. You will learn to gauge the amount to put in quickly. I would be cleaning the grinder every few days at the least.
Have you run a coffee machine cleaner in the group head? Like this, https://www.coffeeparts.com.au/cafetto-1kg-espresso-group-he… . If you you can have crap building up in there.
Clean your grinder every few days? I think that's a bit over the top,I only have a poke around every couple months with a brush to check there's no unusual build up.
You can safely put a few days worth of beans in the hopper at a time with the lid on, it's only ALDI beans, but store the rest in a sealed container away from light and look for stuff with a roast date. After a couple months there will be a significant loss in quality so consider buying smaller bags more often for freshness, or you can freeze beans in an airtight container. Just don't keep opening it up. My process is usually half a kilo goes into the hopper and Airscape and the other half goes straight in the freezer. When I'm nearly out I get the rest out and let them come to room temperature before opening so there's no condensation.
Back to the grinder if you aren't single dosing, you can just grind half a second into the bin for the first shot of the day to get rid of any stale grounds that are hung up in the machine, this is more important with cheap grinders that have lots of retention and clumping.
I find Aldi beans (most supermarket beans really) dark/bitter, even more so the older they are from roast date. Try different coffee beans, preferably no older than a month since roasting.
I found the Aldi medium beans were not strong enough in flavour, but the dark beans were too bitter. The Brazil ones were a better compromise but still slightly too bitter. The expiry date on the side of the Aldi bags can give some clue of how recently they were roasted, I usually find they have a mix of bags with some having an expiry date a month later than others.
You should give Aldi's Medium Dark beans a go - think they'll be right in your wheelhouse
Beans will change as they age so it's common to adjust your grind every few days, usually finer, to maintain the same extraction.
You want to aim for about 30sec total shot time at your 1:2 ratio, I notice my shots get faster with old beans so I do a finer grind. Check your grinder dose weight to make sure it hasn't crept lower over time. Bitter can be running too fast but it's hard to tell without seeing or smelling the shot.