WDT tools: Everything you Need to Know
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WDT tools: Everything you Need to Know

WDT started out as coffee forum advice but eventually became part of standard espresso brewing.

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Asser Christensen

Licensed Q Arabica Grader, M.A. Journalism

If you are new to the world of espresso, or if you have been struggling to get your shots just right, a WDT tool may be the answer to your problems.

WDT stands for Weiss Distribution Technique, and even though it can sound complicated and frightening, it’s a simple concept to understand and implement in your espresso workflow.

This blog post will discuss what a WDT tool is and how it can help you make better espresso. We will also dive into some modern espresso history! So, if you’re ready to learn more about WDT tools, read on.

What is a WDT tool?

Essentially, a WDT tool is a small espresso accessory that helps you evenly distribute the coffee grounds in your espresso basket.

It started as a bit of a coffee forum trend and then became a popular tool among baristas worldwide.

Most people know that tamping is necessary before pulling the shot, but WDT takes place before tamping.

The goal of WDT is mainly to:

  • Break up any clumps that might be present in the portafilter
  • And to spread out the coffee grounds in a more uniform layer.

When WDT was first introduced, most users just relied on a single needle, but today it’s possible to buy highly sophisticated designs.

We’ll talk more about those later.

wdt tool 3dprinted
A popular 3d-printed WDT tool design including a base

Who is Weiss? 🤔

As mentioned before, WDT stands for “Weiss Distribution Technique.”

The overly scientific name is a tongue-in-cheek reference to the inventor, a coffee enthusiast named John Weiss, who first explained the technique on the Home-Barista coffee forum in December 2005. 

As they say; the rest is history!

It’s good fun to read the original posts and see modern espresso history unfold.

John Weiss’ explanation for why people should use the tool is still as relevant today as it was back then:

“In my experience, grind, dose and distribution are critical to excellence in the cup – far more so than tamping,” he explained in the original thread (source). 

He then details how many domestic espresso grinders have problems with excessive clumping:

“Stirring is just another way of overcoming grinder design defects,” he notes before offering a practical solution: 

“So one day I tried stirring the grounds around with a needle to break up clumps and even the distribution. I know it sounds odd, but it makes perfect sense to me. Not only does stirring declump the grounds, but the needle evens the distribution vertically, all the way down to the bottom of the basket. I simply cannot get this effect with my fingers.”

(…)

“Call it a crutch, call it whatever you will, but I have not found anything else that approaches the consistency and flexibility of this approach. With good distribution, I can bang out one espressop**n-worthy shot after another. Granted, this is not recommended for pros in a commercial environment – it’s much too slow, and probably unnecessary. But for the home barista, well, at least give it a try before telling me it’s a boneheaded idea.”

Little did John Weiss know that the world’s most prominent baristas would become massive fans of his technique.

WDT started as coffee forum advice and spread to the rest of the world

How to do WDT: Best practice

Before getting into the technique, I should say that WDT must be done with care!

If you’re using the wrong tool or approach, you might create a worse extraction than otherwise!

wdt tool bad design
This design might do more harm than good to your puck prep! ⚠️ The loop at the end of each pin is creating clumps and channels.

Therefore make sure that you’re using a tool with a proper design. Avoid pins that look too bulky – you need something incredibly thin like a needle.

Weiss Distribution Technique: Step by Step Guide

  1. Use a funnel on top of the portafilter. Alternatively, you can cut the bottom off a yogurt or takeaway coffee cup (Weiss actually proposed this solution).
    This way, you avoid making a mess!
  2. Start at the edge of the portafilter. Move in a circular motion around the basket until you’ve done a 360. The depth should be close to the bottom of the basket.
  3. Finish in the middle by going in small circular motions there.
  4. Your final work should look slightly fluffy yet even
  5. Give the portafilter a little downward knock on the counter to help pack the grounds vertically.
  6. After that, tamp and brew

WDT Tool designs 

The original WDT Tool proposed by Weiss himself was a dissecting needle. The combination of a decent handle and a skinny needle was just right.

However, since then, people have come up with a myriad of designs.

While some coffee lovers still use the single needle, it’s more common to see designs that integrate between 3 and 9 pointy objects being employed nowadays.

Many people have experimented with homemade WDT designs. There are some creative ones out there.

  • Use a cork plug as your base and make holes for three needles spaced evenly apart. This is an excellent option if you want something cheap and easy to make at home.
  • You can also use a single needle if you have one lying around. However, this might not be the most convenient option in terms of ergonomics. 
  • 3D printed WDT tools have also become popular. One design, which uses acupuncture needles very cleverly, has become the gold standard. If you don’t have access to a 3D printer, you can often find people on Etsy or similar platforms who sell this tool readymade
  • Of course, many companies have also jumped on the trend and produced WDT tools of varying degrees of sophistication. At the upper end, you have something like the Duomo the 8, which almost takes it to a new level by integrating spinning into the whole thing.

My experience with Weiss Distribution technique

While there’s no denying that WDT is almost part of the standard puck prep nowadays, I don’t necessarily think everybody has to do it.

If we go back to John Weiss’s original posts and think about the purpose, it was to fix the errors of clump-prone grinders.

Today, you have some domestic models that do a great job creating fluffy, clump-free grinds. The Baratza Sette and Eureka Mignon Specialita are both outstanding in this regard.

If you have a solid puck prep and a sufficiently clump-free grinder, I believe you can get by without WDT.

Personally, I prefer using the combination of a blind shaker, a leveler, AND a good grinder. That trifecta almost guarantees a perfect shot every single time, plus it’s faster and more repeatable.

However, sometimes I have to grind finer than usual, which can lead to clumping. 

In that case, it’s handy to have a WDT tool on the counter.

There’s also something slightly therapeutic about raking a bed of finely ground coffee.

I think every modern espresso geek should at least have one WDT tool at home on their bar since they tend to be so affordable. Then you can always decide, whether or not it should be part of your routine.

Read More: 15 Essential Barista Tools & Accessories

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Asser Christensen

Hello, and welcome! I'm the editor & founder of this site.
I have been a coffee geek since I started home roasting more than a decade ago. Since then, coffee has taken me on countless adventures: From ancient coffee ceremonies in Ethiopia to the volcanos of Sumatra.
My background is in journalism, and today I'm also a licensed Q Grader under the Coffee Quality Institute.