Achieving good coffee crema

I’ve been experimenting lately with improving the espresso drinks I make at home. I now feel I’m getting reasonably good results, and certainly the best I’ve obtained so far.

Crema is the cream-like layer of bubbles produced by a good espresso machine. It’s something of a holy grail among coffee brewers. I use a Saeco Aroma (Saeco make the machines for Starbucks). The Aroma sells on Amazon for about $250, although I bought mine (new) on EBay a couple of years ago for about 60% of market price at the time.

Coffee advice websites will tell you to find the right balance between:

  • the grind
  • the quantity of coffee
  • the tamper pressure
  • the espresso machine

These can all be combined in various ways however. I’ve read many many sites and even more comments and it seems no single site has all the info in one place. So in the interests of empirical research here’s the particular combo I’m currently using.

Grind: as fine as you can. I use a simple $50 Cuisinart grinder set on fine. Get one that is adjustable (you might want to make a cafetiere one day rather than  espresso, and this needs a coarser grind).

You can spend hundreds on burr grinders but this is a perfectly fine model, at least for the everyday coffee results I’m interested in. That is, a superior cup, without it becoming a hobby. It also has auto shut-off controlled by the sliding switch so you don’t have to monitor it and can be preparing your cup. The idea here is a uniform grind.

Quantity of coffee: Fill the portafilter insert to the top with unground beans, but not too much (a level, not rounded fill)! I’ve come to believe I was putting too much coffee in. The portafilter is the “handle” that holds the insert and slots into the dispensing area of the espresso machine.

 The portafilter insert.

Inserts can be either pressurized or unpressurized. I use a pressurized one (that came with the machine). This means it has a very fine grillwork that you see in the picture and then below that the holder just has a tiny gap for the coffee to go through. Other people swear by unpressurized (when you really do need a tamper) because they say pressurized methods yield an “aerated” rather than “proper” crema. I have not had a chance to test this yet, as a new unpressurized insert is $60.

The tamper:

Use a good tamper to press down on the ground coffee in in the insert. I use a Rattleware round-handed one, at 53mm, which is 2mm smaller than the insert for the Saeco Aroma. It fits perfectly and feels hefty in your hand. I almost bought the 55mm because I’d measured my insert larger than it really is, but reading the comments at the website switched it to the 53 and I’m glad I did. So thanks for those comments! It’s about $25.

Most sites recommend 30lbs of pressure (which is less than you think). I was pressing too hard (nearly full might) and I think reduced the crema. Here’s a clever way to judge 30lbs: put the insert with ground coffee on your bathroom scales and get a feel for tamping it down.

The espresso machine: Saeco Aroma. List price $300 but you can beat that at Amazon.

I make Americanos. To do this I use the steaming wand at the side there to and press both buttons (hot water and steam). After a little water is in the cup, I turn off the water button and let it steam the water hotter as I grind the beans or do the dishes or whatever. Then I spoon in the coffee, tamp it, and slot the portafilter in (all the way usually, though I don’t know if this makes any difference–the manual says it doesn’t have to go all the way over).

The goal is not just good crema, but lasting crema–should be there as you continue to drink unless you slurp it all up!

Just made.

Almost finished, still there.

This works for me, even with decaf coffee which was giving me a bit of a problem for a while.

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