Why am I getting NO crema?

[jthiessen8]

I am trying out a new (to me) 1 group commercial espresso machine. Everything works great, but, when I pull a shot, it comes out with absolutely no crema. When I use the same coffee on my little home machine......lots of crema. What is the deal?

[HB]

Not a lot of information to go on, so let's cover the usual suspects:

• Is the coffee fresh? Almost too obvious to ask, but I have to ask.
• Does your little home espresso machine have a pressurized portafilter ("crema enhancer")? They can generate "fake crema" from stale coffee where a commercial unit will fail.
• Difference in grinders? Cafes are renowned for running burrs until they're smooth as a baby's behind. I once spoke to a cafe owner who was unaware that the burrs ever needed replacing.
• Pressure difference? If the commercial unit is maladjusted (too low), no crema.
• Water difference? While unlikely, one could be on water treated by reverse osmosis. RO water is a crema killer.

For what it's worth, I've only managed "no crema" espressos with abysmally stale coffee. Pulling espresso with lots of crema is easy; pulling shots having lots of crema and a great taste profile, that's hard.

[jthiessen8]

That is good info, so I will attempt to answer each...

1. Same coffee is being used between both machines. And I just bought it. So it is relatively fresh (i.e. i did not roast it myself)
2. I dont think my little home machine has a presurized portafilter. Just one like any other home machine.
3. I am using the same conical burr grinder for both the home machine and the commercial machine.
4. Its possible the the brew pressure is too low. It has a gauge that is reading "6" bars (i assume), but as I dont have the manual, I am not totally sure about this.
5. Same water source for both.

[MachoSilvia]

A lot of smaller home machines have crema enhancers, look on the bottom of your basket. if it has one hole as opposed to many, it is pressurized, and has a crema enhancer.

Coffee that is bought from the supermarket is rarely fresh. just because you just bought it doesnt mean it's fresh. hunt down a local roaster, and buy coffee you know the roast date of.

just my two cents...

[jthiessen8]

OH!, I see. Yes, it has one hole in the bottom. Geez, I thought I was just great at producing crema....how humbling

OK, there is a roaster down the block. I am going to try out his stuff. Thanks.

Also, what controls the brew pressure on commercial machines?

[HB]

Also, what controls the brew pressure on commercial machines?

They usually have rotary pumps; brew pressure is adjusted by turning the screw on its bypass valve. The pressure adjusting screw for a Procon rotary pump is shown below:


From Procon exploded view; also see Adjusting espresso machine's rotary pump brew pressure?

[jthiessen8]

Well, you guys could not have been more right. I went down the street here in Portland, OR to Ristretto Roasters http://www.ristrettoroasters.com/ and bought their espresso blend. Roasted on site this last Friday. Should it be more fresh than that? Perhaps they could roast it while I wait.

The result......LOTS OF CREMA. OK, I learned my lesson...no more skimping on the beans.

Thanks.