My machine pulls a shot at 9.5 bar(the setting it came with)
I'm a bit shakey to open my machine & start messing with pressure settings.
My Latte's do have a strong flavor to them, but I always thought that was because of my coffee/milk ratio.
Recently I've been to some reputable coffee shops & their Latte's were not as strong as mine, but had a sweeter, mellow flavor which I prefer.

If I lowered my pressure to 8.5 bar, will that make the difference to achieve the flavor that I prefer or should I keep my setting & just use less coffee or add more milk to my Latte's?

I did notice in these Cafe's I visited that they use a much larger cup than I use.
Their's is about 12-16 oz & mine at home is about 6-8 oz.

I guess that almost answer's my own question.
Even though they don't fill to the very top of their much larger cup their obviously using alot more milk than I am & we use about the same amount of espresso.
Hence the mellow flavor as opposed to my strong flavor.

But I'd still like to know if lowering the machine 1 bar down would make a noticable change in taste?

For me 1 bar made a huge difference. I went from the factory setting of 10 down to 9 and things got great. Still a little harsh and intense so out of curiosity I went down to 8.5 bar and the shots got even better (to me). What was an intense bittersweet chocolate and dark fruit became a soft cocoa and medium berry shot. I really like the lower pressure.

I noticed a sizeable change just going .5 bar, some can detect a smaller change, but I've read that most anybody can detect a .5 bar change. I'd suggest trying the adjustment, you may be pleasantly surprised.

Doggone you Tim...now I have to take the case off my machine...again!

Seriously, thanks for the observations.

i am dying to hear more opinions on how pressure affects taste.

after reading tim's comments this weekend on how much he loved the lowered pressure, i took my anita from about 10.5bar (where it came stock) down to 9bar. while i agree that it softens the taste, i found it less appetitizing - definitely softer, but also a little sour. i think (not sure yet) that i liked the brighter flavors that i got at the higher pressure. and this is while pulling ristrettos (where it seems everyone recommends lower pressure).

am i correctly identifying the change in taste as being brighter at higher a pressure? are my tatesbuds less refined if i like the brighter (higher pressure) ristretto?

this is still a work-in-process for me...

scottyg514 wrote:But I'd still like to know if lowering the machine 1 bar down would make a noticable change in taste?

Yes, but what that change is depends on the beans. Decreasing the pressure should mellow a coffee in most regards, but not all. What beans are you and the cafe using?

What gauge are you using, btw? I'm still looking to learn from people here just how accurate many of these gauges are.

SL28ave wrote:Yes, but what that change is depends on the beans. Decreasing the pressure should mellow a coffee in most regards, but not all. What beans are you and the cafe using?

What gauge are you using, btw? I'm still looking to learn from people here just how accurate many of these gauges are.

I have a PF pressure testing gauge thats checked fairly regularly and it's not unusual to find the gauges on machines are out by 1 or even 2.5 bar. I did some research once and most gauges on domestic machines (I don't know about commercials), seem to be made by a few chinese companies and literally cost a dollar or two each. Not that it matters too much, as within a few bars either way of what they are reading, the delta in any pressure adjustment is probably shown reasonably accurately. it's just the absolute pressure that is sometimes wrong.

My suspicion is that the effect on taste is not so much a function of the (relatively small) change in pressure, but the change it forces on grind, to obtain the same pour. It probably also explains why I prefer the E61 single basket over the double and possibly why the la Spaz basket being deeper/smaller diameter than a standard E61 58mm, is said to give a better shot. I would think (based on the physical measurements and area of holes) the ER61 single and the La Spaz double baskets require an almost identical grind, whereas the E61 double requires a finer grind than the single.

hgs wrote:i am dying to hear more opinions on how pressure affects taste.

after reading tim's comments this weekend on how much he loved the lowered pressure, i took my anita from about 10.5bar (where it came stock) down to 9bar. while i agree that it softens the taste, i found it less appetitizing - definitely softer, but also a little sour. i think (not sure yet) that i liked the brighter flavors that i got at the higher pressure. and this is while pulling ristrettos (where it seems everyone recommends lower pressure).

am i correctly identifying the change in taste as being brighter at higher a pressure? are my tatesbuds less refined if i like the brighter (higher pressure) ristretto?

this is still a work-in-process for me...

Did you have to adjust the grind at all? I've found that changing pressures I had to tweak my grind a little. Plus I should note that I prefer the softer flavors of lower pressures.

You could also attempt a slightly warmer pull.

I've found that once I get the other variables realigned around the pressure adjustment I can get the flavor profile I'm looking for (or one that I really enjoy). I agree this is definitely a work-in-progress for me as well.

TimEggers wrote:Did you have to adjust the grind at all? I've found that changing pressures I had to tweak my grind a little. Plus I should note that I prefer the softer flavors of lower pressures.

You could also attempt a slightly warmer pull.

I've found that once I get the other variables realigned around the pressure adjustment I can get the flavor profile I'm looking for (or one that I really enjoy). I agree this is definitely a work-in-progress for me as well.

tough to answer that... i changed my beans at the same time (i know, i know - one thing at a time). but i was waiting for the beans to age a little (they were too fresh), so i took the anita's down-time to lower the pressure. it could be the difference in the beans. recently, i've gone from gorilla's espresso-a-go-go (10.5bar - my favorite), to intelly BC (10.5bar - good, not great), and now using cafefresco ambrosia blend (9bar - good - getting used to it... want to up the pressure and compare again). so the grind is set very tight... so tight that i think it's not blonding fast enough. i get the first sign of extraction at about 11secs. i get about 1.2 oz from a double in about 33secs.

DaveC wrote:I have a PF pressure testing gauge thats checked fairly regularly and it's not unusual to find the gauges on machines are out by 1 or even 2.5 bar. I did some research once and most gauges on domestic machines (I don't know about commercials), seem to be made by a few chinese companies and literally cost a dollar or two each. Not that it matters too much, as within a few bars either way of what they are reading, the delta in any pressure adjustment is probably shown reasonably accurately. it's just the absolute pressure that is sometimes wrong.

My suspicion is that the effect on taste is not so much a function of the (relatively small) change in pressure, but the change it forces on grind, to obtain the same pour. It probably also explains why I prefer the E61 single basket over the double and possibly why the la Spaz basket being deeper/smaller diameter than a standard E61 58mm, is said to give a better shot. I would think (based on the physical measurements and area of holes) the ER61 single and the La Spaz double baskets require an almost identical grind, whereas the E61 double requires a finer grind than the single.

The cafe's I went to were using bean's from Counter Culture based in Virginia (great beans by the way)

I roast my own with my Iroast 2

Does .5 bar make a difference, I think it does. Some believe that there is a noticeable change at much lower pressure changes. Some coffees work better at lower pressures and some work better at higher pressures. In a cafe that uses the same blend you can temperature and pressure profile the blend to get the best it offers. I rarely use the same blend back to back so I have to settle on a median pressure.

As to the pressure gauge tolerances on some machines, they are there as a guide, not an absolute reference. Let your taste be your guide and the gauge a reference point. All three of my machines had relatively accurate pressure gauges but two of them I added aftermarket. If the gauge reads 7.5 bar and I like the taste, that is where it stays. My Isomac with a vibe pump runs at 8.7 bar, my Faema rotary is set at around 8.9 and my Elektra is 9.1.

Once you change the pressure, you now have to experiment with grind and dose changes to see how it performs. Your technique needs to be developed so your shots are consistent otherwise you wont know if the change was due to a pressure adjustment, dose adjustment, grind adjustment, distribution adjustment, tamp adjustment or just shot to shot variances from technique.

If you want a more detailed explanation and examples of changes in the cup with changes in pressure read Greg's Experiments in programmable, variable brew pressure profiling, Brew pressure profiling update 2, Pressure Profiling Update 3