What Is The RDT Coffee Technique? And Who Is Ross?

RDT coffee

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The RDT coffee technique is a quick and easy hack if you often find that grinding your coffee beans using an electric grinder always ends up being a messy hassle.

In this article, I will delve into the ins and outs of the RDT coffee method, the benefits, and why it might be the next best thing to incorporate into your coffee-making routine. 

✔ Quick Answer

The RDT (aka the Ross Droplet Technique) in coffee grinding is a method where a small amount of water is sprayed or sprinkled onto coffee beans before grinding to reduce static electricity. This technique helps minimize the static cling of coffee grounds, leading to a more consistent grind and less mess.

It’s time to elevate your daily brew through the wonderful world of RDT! Let’s dive in.

What Is RDT In Coffee?

What does RDT mean? A bit of background. 

RDT in coffee is an abbreviation of the “Ross Droplet Technique.” It’s named after David Ross, who came up with the idea back in 2005. 

However, it was only recently that this practice really took off when a member called Chris over at the home-barista.com forums resurfaced the idea.

This led to a large forum thread full of excited coffee enthusiasts comparing their grinder static issues to their results when they used the RTD method.

So what exactly is RDT?

Simply put. This process involves adding one or two water droplets or lightly spraying water mist over your coffee beans before you grind them.

You can use a teaspoon to add water droplets or even use your damp finger to combine and mix moisture onto the beans. 

But using a fine mist spray bottle is probably going to be your best option as it ensures that each of your coffee beans are evenly coated with a fine layer of moisture. 

Trust me, there is a method to this madness, and it’s all to do with reducing static.

Sounds strange, I know, but bear with me. 

What Problem Does The RDT Technique Solve? 

Have you noticed that when you use your electric grinder, the freshly ground coffee that exits the grinder clings to almost anything, making a mess of your grinder and countertop before you’ve even started brewing? 

Well, the RDT method solves this problem, and it’s all to do with science. 

Static is to blame for your ground coffee jumping and clinging to anything it touches. As your coffee beans pass through your grinder and make contact with the burrs, you get some friction. 

When the friction builds up, electrons are transferred from one object to another, creating a charge imbalance that causes static. 

These static charges cause the grinder and coffee particles to act like two magnets with their north poles facing each other they repel.

The RDT approach solves this problem. 

Adding a minimal amount of water to your whole coffee beans before grinding makes the environment within the grinder more conductive, which allows the static charges to dissipate. 

Lots of static with no RDT
Lots of static with no RDT
Results from doing RDT to the coffee
Results from doing RDT to the coffee

This reduces the static-loaded coffee grinds, and the problem disappears. 

Can Ross Droplet Technique (RDT) Damage Your Grinder?

Your right to be concerned about adding water to your coffee grinder; you’ve probably forked out a small fortune on one of the best coffee grinders in the market. The last thing you want is to f**k it up. 

But in truth, all coffee grinders are dealing with small amounts of water all the time, whether it’s from low humidity or a small amount of moisture in the coffee beans.

In a way, by introducing a few drops of water, you are really just simulating higher humidity for your grinder. 

Also, tests by some of the industry’s leading veterans have shown that using the Ross Droplet Technique for many years causes no additional damage or rust to your grinder. 

You don’t have to worry if you’re using only a few drops. 

But Keep In Mind

Don’t go overboard with the water. While coffee grinders are fine with small amounts of moisture, they don’t play nice with lots of the stuff! 

So always edge on the side of caution and use the smallest amount of water you can. I recommend using a small spray bottle to spritz the coffee with a very fine mist – but you’ll still want to stir the beans afterward to ensure each bean is coated.

Also, don’t run off and “pre RDT’ing” your coffee beans, and definitely don’t add cups of water to your bean hopper.

The water should only be added when single dosing (weighing out each dose of beans as you need them), and the water should always be added immediately before grinding. 

Leaving your whole coffee beans sitting in a wet moist environment overnight or for an extended time will deteriorate the flavor compounds.

They won’t taste as good when you go to brew with them.

What Is The Difference Between RDT And WDT?

Acronyms in the coffee world can be confusing, especially for anyone just starting out on their journey.

RDT is what this article is about, and if you’ve got this far, you will know precisely what it means. 

WDT, on the other hand, is entirely different. 

WDT stands for The Weiss Distribution Technique and essentially involves using a small needle or collection of needles to break up clumped-together coffee grounds inside an espresso portafilter basket prior to tamping. 

I have written an entire article on WDT in coffee which you can find here.

RDT is done before you grind your coffee, and WDT is done when your coffee is ground and sitting in your espresso basket. 

Honestly, If you pre-moisten your coffee beans, you will find that you will have less work distributing your coffee grounds – it helps to prevent “clumping.” 

RDT Coffee Conclusion 

So there you have it. The Ross Droplet Technique, or RDT in espresso or coffee, is a quick and easy hack that eliminates static buildup from inside your grinder. 

It might sound crazy, but it works.

Give it a go and see the results for yourself. But remember, don’t go overboard with the water.

Just a slight mist and a shake or a few tiny drops moved around with your finger is all that’s needed. 

Need a small spray bottle? This is one that I use

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