Science Discovers What We All Missed: More Than An Anti-Static Hack

Summary

This video script explores the science behind the Ross Droplet Technique (RDT), a popular method of spraying coffee beans with water before grinding to reduce static electricity. The discussion delves into a new scientific paper that reveals unexpected effects of this technique on espresso brewing, including changes in flow rate and extraction. The paper's author, chemistry professor Chris Hendon, shares insights on the role of water in mitigating static and the potential for 'electroclumps' to impact coffee quality. The script invites viewers to participate in an experiment to further investigate these findings across different grinders and brewing methods.

Takeaways

• 😲 The Ross Droplet Technique (RDT), which involves spraying coffee beans with water before grinding, has been found to reduce static electricity and make the grinding process less messy.
• 🔬 A new scientific paper delves into the effects of adding water to coffee beans, revealing that it may have a significant impact on coffee brewing, particularly with espresso.
• 👨‍🏫 Christopher Hendon, a professor of chemistry, contributed to the paper and discusses the chemistry behind the static electricity generated during coffee grinding.
• ⚡️ Two main processes generate static electricity when grinding coffee: triboelectrification and fractoelectrification, involving friction and heat, respectively.
• 🌐 The paper found that coffee beans can carry both positive and negative charges after grinding, and this charge can vary widely, making it hard to predict.
• 💧 Water is an effective dielectric medium that helps mitigate static charge by interacting with charged particles and dissipating heat.
• 🤔 The paper raises questions about the necessity of scientific research into everyday coffee practices, such as adding water to beans, and whether it's worth the effort.
• ☕️ Experiments in the paper showed that adding water to beans before grinding changed espresso brewing dynamics, with a decrease in flow rate and an increase in extraction.
• 💦 The recommended amount of water to add is 20 microliters per gram of coffee, which is more than many people typically use.
• 🔄 The presence of 'electroclumps'—aggregates of coffee particles held together by static charge—can affect the evenness of espresso extraction.
• 🧐 The video script calls for further experimentation to understand the full impact of water addition on different types of coffee grinders and brewing methods.

Q & A

What is the RDT or Ross Droplet Technique mentioned in the script?

The RDT, or Ross Droplet Technique, is a method of spraying coffee beans with a little water before grinding to reduce static electricity and make the grinding process less messy.

Who is Chris Hendon and what is his contribution to coffee science?

Chris Hendon is a professor of chemistry at the University of Oregon. He has contributed to coffee science by publishing papers on coffee, including the phenomenon known as turbo shots and the recent findings on the effects of water on coffee grinding and brewing.

What are the two main ways static electricity is generated when grinding coffee?

Static electricity is generated through two main processes: triboelectrification, which involves friction during grinding, and fractoelectrification, which is related to the heat and breakage of the coffee beans during grinding.

Why is water effective in reducing static charge in coffee grinding?

Water is effective because it is a polar dielectric medium, meaning it can interact with charged particles and neutralize them. Additionally, water dissipates heat, which can affect the amount of charge generated.

What is an 'electroclump' as described in the script?

An 'electroclump' refers to a cluster of coffee particles, both large and small, that have come together due to opposite charges attracted to each other during the grinding process, forming an aggregate that can affect the flow and extraction in brewing.

What was the surprising finding from the scientific paper regarding espresso brewing?

The surprising finding was that adding water to coffee beans before grinding resulted in a dramatic decrease in flow rate and an increase in extraction when brewing espresso, suggesting that water might have a significant impact on the brewing process.

What is the recommended amount of water to add per gram of coffee according to the paper?

The paper recommends adding 20 microliters of water per gram of coffee, which translates to approximately 0.36 grams of water for an 18-gram dose.

Why might the addition of water to coffee beans have different effects on different grinders?

The effects may vary due to differences in grinder materials, burr types, and whether the grinder has a bottleneck that could affect the grinding process and the generation of static charge.

What is the role of an ionizer in a coffee grinder?

An ionizer neutralizes the static charge on coffee particles by emitting ions that counteract the charge on the particles. However, it may not prevent the formation of electroclumps if the de-electrification occurs after the particles have already aggregated.

How can readers participate in the ongoing experiment regarding the effects of water on coffee grinding?

Readers can participate by conducting their own experiments with their espresso grinders, comparing brew times with dry beans versus beans that have been sprayed with water, and then reporting their findings through a provided Google Form.

What are some of the unanswered questions that the script suggests for further exploration?

Some unanswered questions include whether adding water impacts the taste of the coffee, whether it affects filter coffee brewing, and whether the slower flow rate and higher extraction from adding water can be achieved through grind adjustments alone.

Outlines

00:00

😲 The RDT and Coffee Static Electricity

The script introduces the Ross Droplet Technique (RDT), a popular hack for reducing static electricity when grinding coffee beans by spraying them with water. It mentions a new scientific paper that delves into the effects of this technique, revealing surprising findings. The author discusses a meeting with Chris Hendon, a chemistry professor and co-author of the paper, to explore the science behind the RDT. The conversation covers the causes of static electricity during coffee grinding, namely triboelectrification and fractoelectrification, and how water acts as a dielectric medium to mitigate charging and dissipate heat, potentially altering the coffee's surface chemistry and the grinding process.

05:00

🤔 The Science Behind Adding Water to Coffee Beans

This section questions the necessity of a scientific paper on the RDT, given the apparent benefits of simply adding water to reduce static. However, the discussion shifts to the impact of water on espresso brewing, where the paper's tests showed significant changes in flow rate and extraction when water was added to the beans. The author recounts his own experiments with different grinders, revealing inconsistencies in the effects of water addition on brew time and extraction, and introduces the concept of 'electroclumps' formed by charged particles, which could affect espresso flow and extraction. The potential risks and benefits of adding water to grinders are also considered, along with the role of grinder design in the formation of electroclumps.

10:01

🔬 Experimenting with Grinders and the RDT

The author shares his experiments with various coffee grinders, attempting to replicate the findings of the scientific paper. He discusses the unexpected results from using different grinders, some of which showed dramatic changes in espresso brewing times when water was added, while others did not. The role of grinder design, particularly the presence or absence of a bottleneck in the grinding mechanism, is hypothesized to affect the generation of static electricity and the subsequent benefits of the RDT. The author calls for a wider audience to participate in further experimentation to gather more data and insights into the effects of the RDT on coffee brewing.

15:02

📊 Inviting the Community to Explore the RDT's Impact

In the final paragraph, the author invites the coffee community to participate in an experiment to measure the impact of the RDT on their espresso brewing. He provides a detailed method for conducting the experiment, including the use of a Google Form to collect data on grinder models, grind times, and brew times with and without the addition of water. The author acknowledges the potential risks and the need for informed consent when experimenting with adding water to the grinder. He also raises further questions about the RDT's impact on taste, filter coffee brewing, and the possibility of using water addition as an alternative to grinding finer for higher extraction. The author expresses gratitude to Chris Hendon and his team for their contributions to the coffee science community and encourages viewers to share their thoughts and experimental results.

Keywords

💡RDT (Ross Droplet Technique)

The Ross Droplet Technique (RDT) is a method of spraying coffee beans with a fine mist of water before grinding, which is believed to reduce static electricity and make the grinding process less messy. In the video, the RDT is discussed as a common hack in the coffee community, and the presenter mentions that a new scientific paper delves into its effects, revealing surprising findings about its impact on coffee brewing.

💡Static Electricity

Static electricity is a type of electric charge that builds up due to an imbalance of positive and negative charges. In the context of the video, it is generated during the coffee grinding process, causing small particles to become charged and create a mess. The script mentions that the RDT helps mitigate this issue, and the scientific paper explores the underlying mechanisms.

💡Triboelectrification

Triboelectrification is a process where static electricity is generated through friction between two different materials. The video script explains that this is one of the main ways static electricity is produced when coffee beans are ground, contributing to the messiness of the process.

💡Fractoelectrification

Fractoelectrification refers to the generation of static electricity through the mechanical breakage of materials. The script describes this as another way static electricity is created during coffee grinding, where interfacial heat from the breakage leads to charging.

💡Coffee Grinder

A coffee grinder is a kitchen appliance used to reduce coffee beans into smaller particles, which is a necessary step before brewing coffee. The video discusses various types of coffee grinders and how the addition of water to beans can affect their performance and the quality of the brewed coffee.

💡Dielectric Medium

A dielectric medium is a substance that can insulate or reduce the movement of electric charges. In the video, water is described as a good dielectric medium that can help mitigate the charging of coffee particles during grinding by interacting with opposite charges.

💡Espresso Brewing

Espresso brewing is a method of coffee preparation that involves forcing pressurized hot water through finely ground coffee beans to extract the coffee. The script reveals that the addition of water to coffee beans before grinding can significantly affect espresso brewing, leading to changes in flow rate and extraction.

💡Ionizer

An ionizer is a device that emits ions to neutralize static electricity. Some coffee grinders are equipped with ionizers to reduce the static charge on coffee grounds. The video discusses how ionizers may not fully address the issue of electroclumps formed during grinding.

💡Electroclump

Electroclump is a term coined in the video to describe a clump of coffee particles that stick together due to static electricity. The script suggests that the presence of electroclumps can affect the evenness of coffee bed density and flow in espresso brewing, and that spraying water can prevent their formation.

💡Particle Size Analyzer

A particle size analyzer is a device used to measure the size distribution of particles in a sample. In the video, the presenter mentions using a particle size analyzer to compare coffee grounds with and without the addition of water before grinding, noting that the distribution was largely identical despite changes in brew time.

💡Experimentation

Experimentation in the context of the video refers to the process of testing and observing the effects of adding water to coffee beans before grinding. The script encourages viewers to participate in this experimentation to gather more data on how this technique impacts coffee brewing across different grinders and brewing methods.

Highlights

The Ross Droplet Technique (RDT) is a popular hack for reducing static when grinding coffee beans, making the process less messy.

A new scientific paper delves into the effects of adding water to coffee beans before grinding, revealing surprising findings.

Christopher Hendon, a professor of chemistry, co-authored the paper and discusses the RDT's impact on coffee brewing.

The paper is freely accessible, encouraging readers to explore the detailed scientific findings.

Static electricity is generated during coffee grinding through triboelectrification and fractoelectrification.

Coffee beans can carry both positive and negative charges after grinding, with varying charge uniformity.

The paper demonstrates how to measure and visualize the charge on coffee particles using charged plates.

Adding water to coffee beans mitigates static electricity, possibly through its dielectric and heat-dissipating properties.

The paper suggests that the amount of water needed to neutralize charge might be higher than commonly used in the RDT.

Experiments show a significant change in espresso brewing dynamics when using the RDT with increased water.

The presence of 'electroclumps' may affect the evenness of coffee bed density and flow rate in espresso brewing.

Ionizers in coffee grinders may not prevent electroclumps from forming due to the timing of charge neutralization.

The impact of the RDT on coffee brewing varies across different grinders, with some showing dramatic effects and others none.

A call to action for coffee enthusiasts to experiment with the RDT and share their findings through a Google Form.

The potential impact of the RDT on filter coffee brewing is still unknown and open for further investigation.

The paper raises questions about whether the taste of coffee is affected by the RDT and if it's a preferable method to adjusting grind size.

The use of a particle size analyzer shows inconsistent results across different grinders when adding water to beans.

The scientific community and coffee enthusiasts are encouraged to explore and share more questions and findings related to the RDT.

Transcripts

- If you grind coffee at home,

you've probably come across someone on the internet,

someone like me, telling you

to get a little spray bottle like this

and to spray your coffee beans before you grind them.

Now this little hack has been around for a long time

and it's often referred to online as the RDT

or Ross Droplet Technique.

Doing this reduces the static generated

when you grind coffee

and it makes the whole thing way less messy.

A very good reason to use it, I think.

But today there is a newly released scientific paper

diving into what's going on,

and they found something we all missed.

Something that I think is super surprising

and extremely interesting.

This is the paper.

Very kindly, one of the authors,

Chris Hendon, who you might be familiar with,

because he's published papers on coffee stuff before

that led to the phenomenon we now know as turbo shots.

Well, he shared the paper with me early

and gave me a chance to kind of read and digest it

and then I got really lucky

because he was passing through London

and so I grabbed my most intellectual turtleneck,

grabbed a little studio to borrow,

and we sat down and had a conversation

about this whole thing too.

Please introduce yourself.

- I'm Christopher Hendon.

I'm a professor of chemistry at the University of Oregon.

- Now the paper is free to read in its entirety.

It's not paywalled and it's linked in

the description down below.

So I would encourage you to go and read it,

but we're gonna cover it in three parts.

Firstly, we're gonna talk about why you need

to add water in the first place.

Secondly, we'll talk about what happens

when you add water to your coffee beans before grinding.

And then the third part will be this weird little byproduct

that it sort of has,

this effect it has on coffee brewing

and how it might be relevant or even essential

depending on you and your setup.

Let's get briefly a little bit technical.

When you grind coffee,

you generate static electricity in two main ways.

One way is referred to as triboelectrification

and the other way is fractoelectrification.

- The mechanism of that is basically you can

think about as interfacial heating.

- Mmhmm

- Coffee is no different to other materials

in the sense that you're going to rub and break it

during the grinding process

and doing that, you're gonna create a fair amount

of interfacial heat and so as a result

you're going to get static electricity generated.

What you're observing then

after it exits the grind chamber

is small particles ranging from, I don't know,

let's say one micron to a thousand micron

that are carrying positive and negative charges.

- It's effectively, when it's being tumbled around in there,

it's like rubbing the balloon

on the jumper on the hair, right?

- It's also an an extra an effect of breaking.

So this idea of fracturing

or fractoelectrification

is sort of an added example

of how you might get interfacial heating

and then charging.

- Now, one of the interesting things from this paper

is that they found that coffee

was not particularly uniform in the way

that it sort of generates a charge

in the overall charge generated by grinding that coffee.

It might charge overall in a negative way,

extremely negative, or maybe a little bit negative

or potentially positive.

There were some broad correlations,

but it was I think, very difficult to predict.

If you just gave someone coffee

and said, when I grind this, how will it charge?

The interesting thing is you can measure it

in a few different ways

and you can also visualize it quite nicely.

One of the things that they did,

and they shared some footage of,

is that they set up two plates

on the exit chute of a grinder.

One will be negatively charged as a plate

and one will be positively charged.

And as the coffee exits the chute,

if it carries a strong charge,

it will be attracted to its opposite.

So negative particles will flow towards

the positive plate and vice versa.

Positive charges will flow towards the negative plate.

For most of us, we've experienced the charged particles

in a different sort of way.

They have made a terrible mess of our grinders.

They've gone and flown out and stuck to things

or gone all over the counter.

They haven't gone where we wanted them to go.

And so getting rid of this static charge has been

something of a quest for coffee grinder manufacturers.

And so people have found a little hack.

They've added water to the beans

and discovered that when you do that

you don't get this big mess around the grinder

because you're kind of getting rid

of the static electricity.

Well, what exactly is going on?

- Water is a a very good dielectric medium

in the sense that it is polar,

so the oxygen in water is negatively charged.

And the hydrogens are positively charged,

meaning that they can interact with things

that are of opposite charges to either of those atoms.

And as a result, water is very good

at mitigating charging of solutions

evidently during grinding as well.

But water also has other properties

that are useful

for mitigating static accumulation.

It's very, very good at dissipating heat.

The amount of charge does depend on

how high a temperature you go.

And so as a result, having water around

probably serves multiple roles:

On one hand, it's probably changing the surface chemistry

of the coffee and also of the burrs,

it's probably also cooling the burrs

and also cooling the coffee.

It's probably acting as a sort of interfacial barrier

between any charge that's forming,

maybe going into the water rather than accumulating

on the coffee and perhaps other effects as well.

- Now at this point, you might be wondering

why do we need a scientific paper about this?

I know that adding water to my beans,

if I give it a little spray,

well that gets rid of the static

and everything is all well and good.

Or maybe you've gotta grinder with an ionizer

and you're like, well, I don't have to worry

about this anyway.

Is it really worth spending the time and energy

and money doing the science here?

And on my first read of the paper,

by the time I was maybe two thirds of the way through,

I kind of maybe felt a little bit the same.

And then I hit a fascinating little section

all about espresso brewing.

You see, they said in their testing

that when they did this technique,

when they added water to the beans,

there was a real change in the way

that the espresso brewed afterwards.

They saw a dramatic decrease in flow rate

and a dramatic increase in extraction.

And I thought, hang on, this doesn't track.

I've been doing this for ages.

I've never seen anything like this in my own experiments.

I've never seen any real change in flow rate.

And then I had to read the paper again,

read it properly,

because this is where it gets interesting.

Because they were measuring the charge,

they could measure how much water they needed to add

to kind of truly neutralize the charge.

And they were dosing the water

at a much higher level than I had been previously.

They had been recommending 20 microliters

per gram of coffee.

I don't expect you to do the maths right now,

but I'll tell you for a, say, an 18 gram dose.

That's 0.36 grams of water.

Still not very much,

but if you convert it to spritzes

or sprays of water, well that might be three to four

sprays of water for an 18 gram dose.

Way more than I was doing.

I was doing one spray on the beans.

That was enough, little shake, in the grinder, on we went.

This seemed to suggest

that something really interesting was going on here

and water was having this whole other effect

on espresso brewing that needed to be explored.

So the question's gonna be why?

Why would adding water change the flow of espresso?

And talking to Chris, he had a theory.

He suggested that what was happening

is that when you're grinding coffee

and you're generating all these charged particles,

well they're not all charged the same way.

You'll have some positive and some negative.

And if you had say a large positively charged piece,

well it may well attract a bunch of negatively charged fines

that would stick to it to create what he calls an aggregate

and what I'm gonna call an electroclump.

Can I call them electroclumps?

- Electroclumps...

- Well, they're not electric,

they're not electrified anymore.

- Awhh

- So you're basically gonna say when when you grind coffee,

you produce fines and boulders.

- Yeah.

- And if you don't de electrify,

they will exit the grind chamber as an electroclump.

- Yeah, because that's a specific type of clump.

- Sounds good to me. - Okay, fine.

I know it's a stupid word,

but I feel like 'aggregate' is also a serious word.

And this is, well, this is just much more me,

so I'm gonna call it an electroclump.

He argues that the presence of electroclumps

in your portafilter, once you've tamped that coffee down,

reduces the evenness of the flow.

It reduces the evenness of the bed density

and they're bad.

And when you spray water,

you prevent the static forming

and it prevents these kind of electroclumps forming

and the fines are kind of free

to be evenly distributed in the puck

and therefore you have these slow flow rates

and higher contact times

and therefore higher extractions and less channeling, too.

Seemingly a total win-win.

Now before we go any further on this,

we have to ask a slightly different question

because you are probably now thinking

the same thing that I was thinking at that point,

which is four sprays per dose of beans.

That's a lot of water going

into the very nice coffee grinder

you might've bought and spent potentially

a decent amount of money on.

Is there a risk here?

- In our hands, we didn't see a moisture accumulation

in our grinder.

We did see a change in internal humidity

in the grind chamber,

but that returned to equilibrium, which on the day

that we did this, was 40% very rapidly,

you know, in a matter of let's say,

timeframe of a minute rather than waiting a long time.

'cause there's drips of water in there.

We also thought originally that grinding frozen coffee

was going to be a problem for our coffee grinders

and we haven't seen any real problem with that.

This may prove to be the same,

that a small amount of water may dissipate rapidly

and we'll never really see an issue.

- We do need to talk a little bit more,

I think towards the end of this video

about the potential for you and experimenting

with this stuff and how you feel about it

and how I feel about that much water going into a grinder.

'Cause I think it is still an unknown,

but for now I wanna move on to ionizers

because this is interesting.

If you're not familiar with ionizers,

well a number of grinders now have them.

Grinders like the Ode Gen 2 or the DF64 Gen 2

or I think Acacia sells a stand alone ionizer

originally designed for its Orbit grinder.

They are increasingly popular

and I think have come way down in price.

And for many manufacturers

they've been a nice way to improve the kind of experience

and quality of life of the end user.

When a theoretical electroclump forms,

it will neutralize any charge that it has.

The positive has meant the negative.

There is no net charge anymore.

An ionizer will only work on a charged particle.

And so if you have an ionizer on a grinder,

theoretically it shouldn't affect

the presence of electroclumps

- In a coffee environment,

you're gonna point the negative side of the ionizer

at, in principle, positively charging coffee

and you're gonna neutralize that charge

by bombarding it with negative ions.

The problem with that is,

is that the de-electrification step there

has occurred after the particles have

exited the grind chamber

and have flown through the chute

of your grinder or whatever.

And during that time where the coffee is charging

whilst grinding

and then exiting and falling,

the small particles and large particles,

which may have opposite charges, do have time

to finding each other and form an aggregate.

These clumps then are seemingly charged neutral,

or close to that, which means

that your ion beam is not going to break apart those clumps.

It's just going to minimize charge

of other particles that may be charged.

- So when it comes to a scientific paper like this,

one of the first things you're gonna want to do

or I would want to do

is see if I could replicate the findings from it.

And this is where things got interesting.

You see now in their paper they just used one grinder,

they used the Mahlkonig EK43.

It's a commercial grinder.

It's very popular across the coffee industry.

And I guess if you're thinking about the coffee industry,

this is a pretty good grinder

to pick to do that experiment.

Fortunately for me,

I have a bunch of other grinders here

'cause I'm doing a bunch of testing on grinders

and so I wanted to replicate this across different grinders

and this is where things did not go as I expected.

I'll talk you through my experiments

and my results so far.

I'll be honest, I wish I had done more testing,

had time to do more testing and test more things.

I'll share areas where we could collectively

do some testing at the end,

because I think if you help me,

we could learn really fast really quickly

and share that information with everyone.

Let's start with the first grinder that I tested.

I just did a simple test using a grinder called the DF64.

It's the Gen 2, it has an ionizer on it,

it's a flat burr grinder.

And I used it, I dialed in normal beans,

dry beans so to speak,

and I pulled a 28 second shot using 18 grams in

and about 38 grams out.

That's the kind of overall recipe.

I then added four spritzes of water to the beans

and my resulting shot time went up to about 38 seconds,

a dramatic change.

So I thought, okay, this is it.

This is happening.

It just has to be this higher dose of water

and you get the benefit and you get the results.

But then I tried it with a different flat burred grinder.

The Eureka Mignon Oro,

similar burr size,

similar RPMs on the grinder,

but there, I saw no impact on brew time

from adding the additional water - like none.

Did I see a change in extraction?

Maybe, not significant.

Yes, there was a small increase,

but I'm not sure I would claim it statistically significant.

It was much, much smaller as well as an increase

compared to the much slower sort of brew time

that came with the DF64 Gen 2.

This was strange.

What exactly was going on here?

Here comes a little bit of speculation on my part.

As Chris mentioned earlier on,

there's these two ways that charges are formed in grinders.

There's fractoelectrification and triboelectrification.

I would say that the charge from fractoelectrification

is probably similar across many grinders

as long as they're producing broadly similar grind profiles.

But I think there's gonna be big differences

in the triboelectrification piece.

Different materials that would be of grinders

or of burrs will result in different kinds

and quantities of charging from triboelectrification.

But I also think there's something else at play.

If you have a grinder,

you may know that some grinders

will grind the same speed

for say filter coffee at a coarser setting

and espresso at a finer setting,

while other grinders will take much longer

to grind for espresso than they would do for filter.

This I think is a really potentially important difference

in the one that grinds the same times for both.

Well, there's no bottleneck in the system

at finer grinds.

Grounds aren't being stuck in the burrs.

They're probably being fed slowly.

It might be an auger system

or something like that that prevents all the coffee

flowing straight into the burrs,

getting kind of jammed up there a little bit

and kind of slowly getting sort of pushed out

and fed through.

Where you don't see a bottleneck,

I think you just end up generating less charge

through triboelectrification.

The beans aren't being rolled around,

the grounds aren't being rolled around

and tumbled and re-ground potentially.

And so in grinders like the Eureka

where the grind time is identical

for espresso and for filter,

I don't think you saw the same benefits

from this thing here.

Now I've tried this across a few different grinders now.

I've got half a dozen grinders here at the studio.

I don't have enough.

And so while this correlation has broadly shown up

where you know bottle necked grinders really benefit,

while grinders that have no bottleneck

don't really benefit the same way,

I think we need to take this to a wider audience

and that includes you.

So if you're willing to take part in an experiment,

I'd love for you to do this with me.

It should be a relatively simple thing to do.

Dial in your espresso grinder, if you make espresso,

with normal dry beans,

no spraying at all.

When you're dialed in,

measure your brew time for a fixed recipe,

then add the appropriate amount of water to the beans.

It's gonna be about three to four sprays

if you're using around 18 grams of coffee.

Then record the brew time of the spritzed bean shot.

It might be the same, it might be very different.

There's a Google Form linked down below

and it's gonna ask you what make and model

of grinder you have.

It'll also ask you if you'd know for sure

whether it grinds for espresso slower than filter.

If you don't know, just skip this one, it's fine.

Then it's gonna ask you for your brew time for dry beans

and your brew time for spritzed or RDT beans there as well.

Now please only take part in this experiment

if you're comfortable adding that much water

to a dose of beans and grinding it.

Personally, I don't think on a single use like this

there's any real risk to your grinder,

but it's your grinder, it's not my grinder.

And so, you know, informed consent

is important in all things.

There is, I suppose, technically some risk with it.

I don't think much, Chris doesn't think much,

but I should flag it if I'm gonna ask you to do a thing

and experiment that particular way.

I'm very much aware that there are still

some pretty big unanswered questions

that I think are extremely relevant to this paper.

One might be: does this impact filter coffee?

I don't know.

I haven't been able to do the testing

where I feel like I can isolate all the variables

of the brewing process

away from the variable of adding water

to the beans before grinding them.

But I intend to do more experiments in the future.

And if you do some yourself,

please share it with all of us.

Then I think another great question,

which I don't have an answer for yet,

which is, okay, let's say you add the water to the beans

and you get this slower flow rate

and you get this higher extraction,

does that taste better?

Is that somehow preferable

to just having a slightly finer grind

and producing the same contact time

and the same brew time to sort of aim

for a similar extraction

just using grind rather than using the addition of water?

Now the theory has been that for many grinders,

grinding finer can produce lower extractions.

You kind of hit a wall where you grind so fine

that you get channels and uneven flow.

This is extremely relevant to Chris's previous paper

that we covered on this channel as well

where he encouraged people to grind coarser

and use sort of longer ratios

to hit the same extraction.

But doing so, you know, you would have more even flow

because very fine grinds produce uneven flow.

Is adding water to this a way to have, you know,

a bit more range at the finer end of things

or or go that bit finer,

have that slower shot still yield very high?

Maybe with some grinders but maybe not with others.

That's the kind of thing here.

Now I should add, we have a particle size analyzer now

here at the studio and what was fascinating to me

is that the analyzer could see no difference in the grounds

from the DF64 that were producing

this 28 second shot and this 38 second shot.

The distribution was pretty much identical.

And in some cases I saw very small shifts in some grinders

towards an overall finer average particle size

when I was adding water.

But that was not uniform or consistent across every grinder.

At this point I'm unsure if it supports Chris's theory

or works against it.

Overall, I am left as usual

with more questions than answers.

So what's the summary here?

I think this is something that is worth experimenting with

if you're comfortable experimenting with it.

Do you see a change in flow when you add

that little bit more water to your beans before grinding?

And if you do, is that increase worth it to you?

Do you like the taste of it?

These are questions that I cannot answer for you.

I think this is fascinating research

that has opened up a new area of exploration

and I think there's tons of stuff we can learn from it

and new questions that we can ask from it as well.

I'd obviously like to say thank you so much to Chris

for sharing the paper ahead of time,

sharing his time with us to sit down and chat.

It was a very enjoyable conversation.

Thank you to his team for sharing resources too.

And I really like his approach to doing coffee science,

that's trying to benefit as many people as possible,

keeping the science open and accessible.

I think this is a very good thing.

But now I wanna hear from you

down in the comments below.

Or don't forget in that Google Form

where the results will be public.

Have you found this to impact the way that you brew coffee?

Will you be experimenting with this?

Do you wanna try it for filter coffee?

And will you share those results with us

if you do experiment?

I'd love to hear from any and all of you

about your thoughts about this paper,

thoughts about this whole kind of world

of spraying coffee beans.

Is it good, is it bad?

Do we need a different solution?

Let me know your thoughts.

But for now I'll say thank you so much for watching

and hope you have a great day.