# Coffee worse after descale/backflush



## AnOnlyTwin (Mar 28, 2012)

Hi,

***Newbie alert***

So - help! My reconditioned Gaggia Classic was making lovely coffee but had a few leaks so the solenoid and steam valve were replaced - it no longer leaks. While I was at it I thought I'd backflush with Puly Caff and descale with Puly Cleaner. I followed all of the instructions and rinsed thoroughly but the coffee now tastes undrinkably sharp. Naturally, I thought I hadn't rinsed and was tasting cleaner so rinsed again. And again. Then ran the machine without coffee in and tasted the water - hot and tastes fine. Put coffee in - eugh!

Interestingly, single shot pulled in 28 secs, 9g grinds, before the descale/clean became a 15 sec shot with no other changes. So I dialled my grinder in again (a good few twists towards fine on the MC2) and it's a 28 sec shot again, still looks good in the glass (Guinness!) but not nice to drink.

So what's happened? Underextraction/overextraction? Too hot/cold? Too high/low pressure? The coffee was roasted 5 days ago (HasBean Brazillian), I use a 15kg tamp. Interestingly, it tastes marginally better with plain tap water rather than Brita....?! I always aim for 28 sec shot trying to reduce the number of variables.

I've spent the last 3 hours playing with it - 7g, 8g, 9g shots from 15-40 secs and I can't seem to find the sweet spot again....

Help?

Thanks in advance.


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## JamesG (Mar 29, 2012)

If its too sharp its likely to be underextracted. You could try raising the heat in the boiler by turning on the steam switch for 10 seconds or so.

When you altered the dosage did you adjust the grind so the shot time was still the same? If not you could also try a smaller dosage, but this time grind slightly finer so your shot time is still around 28 sec mark.

Hope this helps.


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## chimpsinties (Jun 13, 2011)

Also, you don't mention what you getting out in terms of weight and/or volume. I can assume as it's a single it's about 1fl/oz


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## AnOnlyTwin (Mar 28, 2012)

Thanks for the replies.

Yes, I've read about temp surfing - a 10sec blast before pulling the shot doesn't seem to help.

Good point - I didn't give weights and volumes. Here they are (I wasn't expecting them to have changed - I was looking at it from the perspective of my having altered the machine's behaviour)

1 shot glass = 35mL (28mL liquid plus 7mL crema)

7.65g coffee

28sec

1 shot coffee = 30g

From what I've read, I should aim for about 22% solids, but I don't know whether I'm getting that...?

Thanks again.


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## MikeHag (Mar 13, 2011)

Not sure. Try stopping the shot a little sooner and shorter, as you might be getting into the unpleasant compounds at the end of the extraction.


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## tribs (Feb 21, 2012)

Are you using the same beans as before the changes?

I would agree sharp / sour usually associated with too low temp, bitter / burnt - too hot. Are you able to measure temp of brew water? If not does it flash steam when at full temp?

Also was there much scale removed when descaling. The only thing I can think is if the piping was considerably narrowed as a result of scale buildup which has now been removed altering flow.


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