First shot always slightly bitter

Beginner and pro baristas share tips and tricks.

#1: Post by jjamesee »

Hello guys, any idea why the first shot of the day always tastes a little bitter even when single dosing? Does it happen to you as well?

I use ECM synchronika + zero niche. Before the first shot I always run about 6g of beans through the grinder.

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#2: Post by lrj13 »

Have you tried

Lowering the water temp?
Grinding coarser?
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#3: Post by homeburrero »

If everything is the same, and both shots are from a fully warmed up machine that has been idle for at least a few minutes before the pull, then it may possibly be due to old coffee oils in the machine. See Sink that First Shot
nínádiishʼnahgo gohwééh náshdlį́į́h


#4: Post by jjamesee »

Thanks a lot guys, I haven't tried lowering the temp or grinding coarser, but it could certainly be the old coffee oils, I'll try backflushing before the first and after the last shot of the day and report the results

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#5: Post by Bluenoser »

How long are you letting your machine warm up before first shot? My E61 needs 45 minutes before the group is really warm.. So if you group is cold you might have a low brew water temp and what you are tasting might be sour? (under extracted).. just a thought.. In your second shot, 5-10 minutes later, the group is hotter and so your brew water is higher and you get better extraction. If you are sure the taste is bitter (over-extracted) ignore the above.


#6: Post by Eiern »

I have an ECM as well, a technica profi, and it's not fully warm before an hour. The thermometer I installed in the grouphead tells me this.

Also the machine is not a 'dragon' and I have to be careful to not over flush between shots after the very first one. I need a 10 sec cooling flush before I grind and another short one right before pulling that shot as well or else steam will come out. Are you doing a cooling flush first? There is some youtube videos about that from the guy at this forum with a scace measurng temp.

If the machine has been on long but after that first shot the grouphead is not as hot anymore. I think this might be it as I have never ever thought about first shot being better, I can't believe throwing out the first shot every session, I often only make one shot, and it's often delicious.


#7: Post by Eiern »


#8: Post by Coffcarl »

Consider that it might not be the machine, but your pallette. I have made.the mistake of having my first shot before brushing teeth, or drinking water, and invariably it tastes worse than the second and later shots


#9: Post by jjamesee »

Thanks for the video, it is for a HX ECM though, the synchronika is a dual boiler. I haven't measured myself, but the temperature stability seems consistent. Also it is not a pallette problem, as I drink mostly fruity light roasts and any signs of bitterness are very noticable there, even for someone who doesn't drink coffee much.

Also I forgot to mention, that all shots after the first one are consitently good. I've tried backflushing with water (blind filter) before the first shot and after the last one. I felt like there was some improvement, but will need to test that for longer to get to some conclusion, since the water cannot dissolve the oils properly, I guess it will never be as good as sinking the first shot.

I've also tried running around 12g of beans through the grinder, then sink the first shot and taste just the second one and I was pleased with the result no signs of bitterness at all.

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#10: Post by Jake_G »

Do you perform a "warming flush" before your first shot?

DB E61 machines have a tendency to get a cold nose due to the relatively low temperature offset between the brew boiler and the group as compared to an HX. HX machines have a powerful temperature differential that drives the thermosyphon, and the flush on them is more about dealing with the superheated HX water, whereas the DB machines tend to benefit from a bit of "goosing" to warm the bell a bit.

A quick screen clearing purge is generally sufficient and if this isn't part of your workflow it would explain the difference between the first shot and subsequent shots. Note that a backflush uses deceptively little water and would have less thermal impact on the group than an equivalent purge. A quick sanity check would be to dispense 25ml into a cold demitasse first thing in the morning and see how much it warms the cup. If the cup is relatively cool compared to doing the same thing in the middle of a session, that tells you the first ounce of water through the group gave up some heat on the way out, confirming a cold nose.

If you already do this, then all my rambling was for nothing. :P


- Jake