# acidity and pressure issues?



## tee (Jan 24, 2019)

Hi

I'd be grateful for some advice/help with issues I may? be having with acidity in the espresso's Im pulling and the pressures extraction is occurring-Im not really sure.

I have a Isomac tea BIS (the one with the integrated grinder), use fresh rave coffee (usually the signature blend) and filtered water. Machine preheats for around 45mins to an hour, I usually use 18g of coffee (but must confess dont always measure in the morning!).

Whether I follow recipes, ratio's or not (however successfully!) I notice extracting at 9 bar seems to get crema but the espresso is on the watery side and really quite acidic. (and also extracts faster than expected)

9.5-10 bar gets good crema, slower extraction but is still acidic to some degree

10-10.5 bar seems to get the tasting notes advertised with the coffee's but tastes a little flat and has less crema albeit with more tiger striping?

Is my pressure gauge wrong (or is the operator!?)

Ive tried finer and coarser grinds (watery and sour or choking the machine respectively) but kept the dose at 18g.

Any suggestions? Very appreciated if you do


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## The Systemic Kid (Nov 23, 2012)

Go by taste every time. Don't judge by crema. Sadly, the inbuilt grinder is not ideal for espresso extraction throwing up too wide a range of particle size.

Acidic coffee is associated with under-extraction - tightening up the grind is the way to go.


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