What are the causes of bitter espresso shots?

[Startup]

I've had my rancilio silvia for awhile now with a capresso infinity. My espresso was OK but never great, so I figured it was a combination of the grinder and the coffee I was using. Since then, I've upgraded to a Mazzer Super Jolly, as well as getting a better espresso blend of coffee. My shots are still very bitter, and or sour. I got the grinder used, and i'm thinking that the burrs could be the problem. So my question is, can worn burrs cause bitter espresso? Also, how do I know if the burrs are too worn?

 

[shadow745]

Your description of bitter and/or sour even though you've changed to a much better grinder and different coffee leads me to believe the machine is the main problem. Based on ALOT of complaints/reviews the Silvia seems plagued with temperature issues and it can be difficult to find a sweet spot consistently.


If the burrs have seen heavy use they will grind slower as well as needing to be closer together (finer grind setting) to achieve a proper grind. SJ burrs should easily be good for 500 lbs. if not more.

 

[Startup]

I practice temperature surfing with my machine, so temperature should not be an issue. Should it? Also, I let my machine heat up for around 20-30 minutes before I pull my shot. Could the pressure be an issue with my shot quality? thank your for your help! BTW here is the sellers description of the beans......This blend of four organically grown arabica coffees is designed especially to be brewed in espresso machines. The Brazil provides a traditional base, while Sumatra adds a dark smokiness that cuts through the milk in your latte. Guatemala helps bring out the caramel notes, and Tanzania adds high notes and crema to the shot. It’s teamwork at its best, and enough to get you excited about just about anything you’re facing today.

 

[shadow745]

Have you tried measuring brew temperatures or just surfing between the heating element kicking ON/OFF?

I'd give your machine at least 30 mins. to warm up.

Of course brew pressure can cause issues. No way to know for sure what it's brewing at unless you buy or make a gauge.

Yeah that blend does SOUND good, but fresh matters most. If coffee doesn't have an actual roast date on it I wouldn't suggest buying it. Pretty much any coffee can be great, when it's fresh. Even the best coffees known to man will be crap once stale, especially for espresso as there are no short cuts.

 

[Startup]

Not actually monitoring/measuring temperature...just on and off. Beans have "roasted on" date and pretty new. I'll try the 30 minute warm up. Thank you.

 

[shadow745]

I'd recommend doing simple temperature testing (thick styrofoam cup and digital thermometer) just to see where the sweet spot is. If you're in the 196-202 range that'd be fine for most coffees.

OK so the coffee is fresh, just be sure to store it as to maintain freshness. If coffee is exposed to air for even 1-2 days (sitting in grinder hopper) you can have thin/bitter shots. The window of opportunity for excellent espresso is narrow at best.

 

[roody]

I think that has to be a good Tahoun coffee in order to eat easily. You from grinding your own coffee will be able to control the amount of added everything itThank you

 

[sdelgran]

Have you ever checked your extraction with a naked portafilter? Even with a good grinder like you now have you could be getting some channeling and over-extracting. Depending on how "sensitive" you are on bitterness this could simply be it...

 

[Startup]

So many variables. I'm currently timing and recording temperatures then matching the times to the shots. The naked portafilter may indeed be my next investment. Thanks for all of the continued good tips.

 

[shadow745]

A bottomless portafilter may be OK, but I see them as being more of a wow factor for most than a learning tool. To each his own...

An experienced "eye" will be able to spot signs of channeling, under/over extracting by examining the flow during extraction, integrity of the puck, etc.

 

[Ibrahimzen]

I have the same problem! Mine is RS V3 and I tried to measure the temp after 30 min warm up and temp surfing. I get between 195-200. Though my shots always taste sour... I tried Blackcat and Metropolis redline.It really annoys me could anyone enlighten us please?

 

[f1lupo]

After owning my Rancilio Silvia for a couple of years and not changing anything in my setup at all I started to get very bitter tasting shots. I am religous with cleaning, back flushing, tried changing beans, temp surfing, grinder, changing water type etc etc BUT my espresso shots were still bitter. I finally got rid of the bitter/ burnt taste when I took apart and manually cleaned the 3 way valve. I took pictures for those that are afraid to take apart their Silvia's just to show how straight forward it is AND to prove that back flushing and regular maintenance is not enough to solve this problem.

the site does not allow me to post links yet as I'm a new user but will add it to this thread soon.

 

[CoffeeJunky]

Got it. Thanks. I gave mine to my brother last fall so i will let me brother know what to do when actually it happens.

 

[f1lupo]

here's my blog that details step by step how I solved my probelm, hope it helps other Silvia owners.

http://mancave-ramblings.blogspot.ca/2014/02/bitterburnt-tasting-espresso-after.html