Hi

For a couple of weeks now I've been using a Vario and Expobar Brewtus IV and I've had nothing but bad shots so far. Whatever I do, I always seem to end up with a bitter shot..

- Beans were roasted 5 days ago, tried 3 different beans
- Temperature initially set at 92c, and I lowered it to 90 hoping this would help, no difference
- OPV set to 10 with blind disk
- Using standard double basket with naked portafilter
- WDT for each shot
- 0.01 scale to weigh dose + shot
- Started with a 16g dose, adjusting the grinder to get 30-40g of espresso in +-25s. All bitter shots so I tried lowering the dose. Eventually reached 14g and still too bitter. Decided to try higher doses (don't even know what the reasoning would be, just a desperate attempt I guess), same result. So I tried a LOT of different doses ranging from 14g to 18g, while each time adjusting the grinder to maintain the flow rate.

Used about 750g of beans and got zero decent shots..
Is there anything else I can do? Am I missing something?

Sorry you are having problems, I know how frustrating that is.

Did you consider it might be you? Did you start taking new medicine or do you have cold? I recommend stopping by good espresso shop and trying their coffee with a friend and see whether that's bitter too...

How do the shots look? Are there clear signs of channeling? Maybe try distributing into the pf corners straight out of the vario without WDT'ing. Have you checked your pump pressure?

ds wrote:Sorry you are having problems, I know how frustrating that is.

Did you consider it might be you? Did you start taking new medicine or do you have cold? I recommend stopping by good espresso shop and trying their coffee with a friend and see whether that's bitter too...

No medicines, no cold
I am, I'm visiting shops regularly and tasting good shots (or what I consider good). My girlfriend doesn't like espresso but I let (or rather, make) her taste anyway and she also acknowledges the more bitter taste in my shots at home. Could be psychological I guess, I don't think it is but I'd need a neutral/unbiased person to test

bostonbuzz wrote:How do the shots look? Are there clear signs of channeling? Maybe try distributing into the pf corners straight out of the vario without WDT'ing. Have you checked your pump pressure?

Pressure is set at 10 bar. They look okay-ish to me, but as I'm just starting out it's difficult to be a good judge. I'll try distributing without WDT, and maybe record a video of a shot.

10 bar is likely to give you bitter shots. It should be no more than 9 and perhaps less.

Okay I'll try and set it to 8-9 bar and come back with the results
May I ask what the reasoning behind this is? I thought higher pressure would more likely result in sour underextracted shots due to the water passing through the coffee too quickly, but that's not how it works?

If you are already adjusting your grind so the flow rate is correct and you're at higher pressure, it's equivalent to pulling a shot too hot. Think about a pressure cooker. It cooks faster because the food is under pressure.

Have you brewed these coffees? It might be useful to figure out what they actually would taste like when done right.

Just lowered the pressure to 8-9 bar, and temp to 88, same bitter result
I haven't brewed the coffee yet, I'll give that a go, but for the beans I'm using now I explicitly for asked a sweet as non-bitter as possible coffee when I bought them.
I forgot to keep lowering the temp until I get a sour result so I'll try that next time.