Espresso puck screens are the metal discs that cover the espresso puck. They’re becoming a popular espresso preparation aid. They’re also a bit controversial, as some aficionados say puck screens are essential, and others say it’s totally unnecessary.
The puck screen theoretically reduces channeling and maintenance. While that’s generally true, I’ve found that the value of a puck screen is dependent on your setup and espresso experience. It can be a great way to get more consistency from your shots or a crutch that keeps you from becoming a better home barista. I recommend trying a puck screen and asking yourself if the espresso tastes better.
I’ll go into detail on what an espresso puck screen is, how it works, and why you may or may not need it. This should help you decide whether a puck screen is right for your setup.
What is an Espresso Puck Screen?
A puck screen is a small circle of metallic mesh. It’s designed to sit inside a portafilter on top of ground coffee when pulling a shot of espresso. The mesh of a puck screen should lead to a more balanced extraction.
Let’s look at some of the ways it accomplishes this.
The main purpose of a puck screen is to improve water distribution across the coffee bed. The shower screen on an espresso machine technically does this, but it’s not perfect. Sometimes, water trickles through the screen in different volumes on different parts of the coffee puck.
The mesh on the puck screen is tighter than on the shower screen. Water sits on top of the puck screen and spreads evenly across the whole surface before being forced through. This puts the whole puck in contact with water at the same time.
A puck screen prevents an espresso puck from expanding. When water flows through espresso grounds, the puck grows as gas is released from the coffee. This expansion can leave air pockets in the puck, especially if it isn’t tamped evenly.
The air pockets create tunnels or channels that pressurized water runs through. Water will always take the path of least resistance, so it will move toward these tunnels and away from more compact parts of the puck.
This usually results in water and coffee chaotically spraying out of the portafilter. We call this “channeling,” and it’s a great way to get coffee on your shirt and create a sour espresso shot! More troubling, channeling causes an uneven extraction because water will contact some grounds much more than others. Poor extraction means a poor flavor profile.
A pre-infusion is one method to avoid puck expansion and channeling. A puck screen on top of the ground coffee also stops the puck from expanding. This means no channeling, more extraction, and better flavor.
Paper vs. Metal Puck Screens
A paper screen is an alternative to a metal puck screen. Paper filters will do some of the same things as a metal screen, but not quite as effectively.
A paper screen more evenly distributes water than a shower screen alone, but not as much as with a metal screen. A paper screen also won’t prevent the espresso puck from expanding like a metal screen.
Paper filters work best when you use two at the same time: one on top and one under the coffee bed. The filter at the bottom of the portafilter cleans up the texture and flavor of the shot after it’s extracted.
The better use for a paper filter is to improve clarity. There are a lot of oils and fats in coffee that get extracted as part of the brewing process. Sometimes, these oils and fats can muddy the flavor of coffee or create a thick, heavy mouth feel. A paper filter will keep some of the oils and fats out of your espresso shot.
This usually creates a brighter flavor and lighter texture. It’s like the difference between the flavor of a V60 versus a French press. I personally prefer brighter flavors in my coffee. I also tend to drink espresso shots straight or in a cortado or cappuccino, which has only a small amount of milk.
Adding a paper filter underneath the coffee grounds is an easy way to make brighter, sweeter shots. That brighter flavor may work against you if you prefer richer, more full-bodied shots or like making milk-heavy drinks like lattes.
Do Espresso Puck Screens Work?
So, how effective are puck screens in creating better espresso shots? The jury is still out. Some people swear by them, and others prefer not to use them. We polled a group of Home Espresso Aficionados about puck screens and got an almost even split. Out of over 200 respondents, 51% said “No,” and 49% were “Yes.”
The value of puck screens seems to come down to your preferences. I’ve pulled my shots with and without a puck screen and my take is they help, sort of, with some debate across a few areas:
- Brewing Consistency
- Flavor Profile
- Correcting Poor Technique
These thoughts should help you decide if a puck screen makes sense for your setup and your needs.
The puck screen definitely removes inconsistent brewing problems, like uneven water distribution and puck expansion. The puck screen spreads water around the puck and mitigates channeling.
However, you don’t need a puck screen to get consistent shots. You could prevent channeling with a WDT or better tamping. Also, good espresso machines will distribute water evenly enough to produce consistent shots. Veteran baristas or espresso enthusiasts might notice a difference, but the average coffee drinker will be happy with the extraction you get with only the shower screen.
A puck screen is best thought of as an additional tool that makes your other tools better. If you need it to brew consistently, then there are problems elsewhere in your equipment or technique that need fixing.
It’s also worth noting that the extra mesh layer slows espresso shots. You’ll get over extracted shots unless you grind significantly coarser to get the same brew times without a puck screen. This mitigates the initial benefit of the puck screen…
…that’s why a puck screen works best if it’s a permanent part of your brewing process. Taking the screen out requires a grind adjustment between each shot, and that constant adjustment can decrease shot consistency. These offsetting variables are what make puck screens so controversial.
I haven’t noticed a significant improvement in coffee taste when using a metal puck screen. It can help avoid unpleasant flavors that come from poorly extracted shots, but it won’t do anything to radically improve a shot’s taste. To me, a puck screen improves your coffee by streamlining your workflow. The flavors you get from a puck screen should still be attainable without one.
A paper filter is a different story. A filter underneath the puck will keep some oils and fats out of your shots. That brighter, cleaner flavor is noticeable but also isn’t necessarily better. It’s a different flavor, and it’s up to you whether or not you enjoy that difference.
Correcting Poor Technique
A metal puck screen can keep a shot from being ruined by something like bad tamping. I’ve definitely tamped a crooked puck before, and a puck screen can save a shot from a mistake like that.
This is a helpful aid, but no excuse to maintain bad habits. Mistakes are a great teacher. A puck screen might be a barrier to improvement if you’re still learning how to prepare good espresso.
A puck screen separates the coffee grounds from the shower screen. This stops espresso grounds from getting stuck to the shower screen after each shot. It makes cleaning the machine much quicker and easier.
Again, there’s a tradeoff: the puck screen itself can be difficult to clean. The small holes in the mesh trap more coffee grounds than the shower screen, so you’re maintaining another piece of equipment. However, a dirty puck screen won’t need hundreds of dollars worth of repairs if it breaks, as an espresso machine will.
If I had to choose between a cleaner espresso machine or a cleaner portafilter and puck screen, I’d choose the machine.
Puck Screen Recommendations
Here are a few puck screen options if you decide to use one:
The Normcore puck screen is cheaper, but the Bplus screen is about a half-millimeter thicker. That might make it a little sturdier, but I find the Normcore puck screen does the job just as effectively.
An alternative to the watchget paper filters is to make your own with a hole punch and pour-over filters!
Tinker With Your Setup
An espresso puck screen is either a great way to create more evenly extracted espresso or an unnecessary extra step in preparing a shot. Ultimately, it depends on your preferences. Learn more about dialing in espresso for some other troubleshooting tips.