Bitter coffee and low temperature.

[sched7]

Im constantly getting bitter shots on my Gaggia Classic. Correct me if Im wrong, but a major contribution to bitterness is too high a brewing temperature. Ive done the styrofoam cup test to check my brewing temperature and Im getting an average reading of 70C (160F) which I believe is way below the recommended 185 - 200F. Surely this low temp. would give me a more sour taste? Ive tried various varieties of freshly roasted beans and fiddled around with various grind settings on my Compak K3 to make sure Im not over-extracting (another cause of bitterness). Are there any other factors I should be considering? The low brewing temperature is cause for concern however, so Ive ordered a new thermostat to see if this improves my shots.

Any advice would be gratefully received.

Cheers
Colin

[every1luvsu]

Re: Bitter coffee and low temperature.

It is a lot easier to diagnose a potential problem if we can see the process you go through each time you make a coffee.

Ive never used a Gaggia so I cant comment specifically on that but instead of just thinking temperature of the water, think about the time that the coffee is in contact with the water.

For example if you grind your coffee, tamp, and lock the group head in, and then leave it in while youre texturing your milk, the coffee is sitting in the group heating up. If your shot runs very slowly and youre getting over extraction this could be another problem which you have mentioned.

Of course you may already know this, which is why if we see a video of your general routine, we might be able to pick out some problems which may be causing the bitterness.

[sched7]

Re: Bitter coffee and low temperature.

Sorry I dont have a video however this is my routine:

I tend to follow the routine as suggested by many Gaggia owners which is; switch the machine on, prime the pump, and then let it heat up for no less than 20min. with the empty portafilter attached. After 20+ min. I grind fresh beans (roughly 19g for a double shot) directly into my warmed-up, dry portafilter, use the WDT to remove any clumping and then tamp. I then pull fresh water through the group, before pulling my shot. I manage to pull most of my double shots anywhere between 25 - 30sec however I do usually get a bit of blonding in the last few seconds, which may be contributing to the bitterness. I have stopped shots before blonding occurs, which has improved the bitterness slightly.

I always pull my shot before steaming my milk, so this is not an issue.

Feel free to point out any improvements I can make to my routine, however Im still leaning towards the fact that I have a faulty thermostat which I hope will improve things.

[GregWormald]

Re: Bitter coffee and low temperature.

How many mls in a double shot?

If a bit shorter helps, try **quite a bit** shorter.

My standard is about 25-35 mls of coffee in a double. Caffeine is bitter and is less water soluble than the flavours and hence comes on much more strongly in the last half of an extraction. Also try a new cup about half-way through an extraction and taste each half separately.

Greg

[sched7]

Re: Bitter coffee and low temperature.

How many mls in a double shot?

If a bit shorter helps, try **quite a bit** shorter.

My standard is about 25-35 mls of coffee in a double. Caffeine is bitter and is less water soluble than the flavours and hence comes on much more strongly in the last half of an extraction. Also try a new cup about half-way through an extraction and taste each half separately.

Greg

I tend to measure my doubles as 60ml. Will try and shorten my shots and see what happens. Have also read somewhere about tasting the shot at different phases, so Ill give that a go too.

Cheers

[askthecoffeeguy]

Re: Bitter coffee and low temperature.

The longer you run the shot the more bitter it will be try running it shorter with a finer grind: I aim for 30mls from 30 secs from both my Gaggia Deluxe and Baby Gaggia spare machines at home - and I get a very good extraction from both

Also do you insert the empty handle into the machine and run water through it whilst giggling it back and forth after each shot? As there is a considerable coffee grind build up in the group head after each extraction which translates to bitter coffee in the cup if its not cleaned out immediately after each use

Likewise try taking the shower screen off and giving it a good clean

Hope this helps

Cheers,

Pat