Bitter tasting shots

[SWD76S]

HI,
I have recently purchased a Rancilio Silvia and it seems to be pouring a nice creamy shot as I like however more than 50% of the time the shot is quite bitter. Does anyone have any advice on what may be causing the problem? I am using a local Euroblend bean from my local Coffee shop. Also when i do get it though right the shot is superb.
Cheers
Scott

[sanch]

Re: Bitter tasting shots

Hey Scott,

It might be the water temperature that is causing the shot variability/unpredictability (if youre dosing, tamping etc consistently). There is quite a degree of temperature variation depending on when in the heating cycle you are pulling the shot. Have you heard of temperature surfing? Check out this link:
http://www.coffeekid.com/archived/rancilio/cheatsilvia

Cheers
-S

[sanch]

Re: Bitter tasting shots

OK i just realised that that link doesnt actually explain why they are doing what they are doing.

Im sure im going to get this wrong but basically temperature surfing is working out what time between when the boiler light goes on (i.e. water is at lowest temperature and thermostat kicks in) and when it goes off (i.e. water is fully heated and thermostat cuts out) that the optimum coffee brewing temperature occurs. Does that make sense? Alot of people have experimented with temperature probes and stop watches to work out that x minutes after the light goes on, the water is at y temperature. Ive got the flu and my head is fuzzy so i hope i havent confused you!

I temperature surfed with my silvia for about 5 months and then got a "PID controller" installed to controll the water temperature.

[GregWormald]

Re: Bitter tasting shots

It could also depend on how much you are expressing in each shot. Assuming you have exactly the same amount of grounds in the portafilter, a teaspoon extra expressed beyond blonding can really add to the bitterness.
Greg

[scottishslayer]

Re: Bitter tasting shots

yeh im going with greg, i just purchased a silvia about 2 months ago and had basically no coffee making experience. before i knew what was goin on i would let it pour until the 30/60ml was reached. usually this would lead to about 1/3 - 1/4 of the shot being really blonde, which ulitmately lead to a bitter shot.

now im dosing about about 20g of freshly ground (within 2-3 days of roast) into a synesso ridgeless, but have had great results with a ridged LM and the stock double as well. As soon as the colour changes to that pale blonde i switch it off. the bonus is that if ur trying for a 60ml and it blondes at 30ml, then just switch it off and tell people you were going for a ristetto so you look like you know whats going on

how fresh are the beans that ur using, and what tamper as well?

anyways good luck in making that "god shot"!


cheers
craig

[redzone121]

Re: Bitter tasting shots

Tricky animal but worth it in the end. Had a Silvia for 6 months and loved it.
I agree, bitter in my experience with Silvia was normally if I went into blonding. Some beans also prefer different temps, so you could try slight adjustments to pid.

CB.

[SWD76S]

Re: Bitter tasting shots

Thanks everyone, its no doubt going to take a little more practice with this machine before I can get exactly what i am after. I also found this vid on youtube about temperature surfing and funnily enough its with a Rancilio. Hope this helps some others out too.
http://www.youtube.com/watch?v=QhxvDusY3jk
Cheers
Scott