1 Jul 2026

Making Good Espresso @ Ai

why do they spray water on coffee beans before grinding


Spraying coffee beans with a fine mist of water before grinding—a method known as the Ross Droplet Technique (RDT) — adds a tiny amount of moisture to the beans. This prevents ground coffee from flying everywhere and sticking to your grinder's chute due to static electricity. [1, 2]

Benefits of Spraying Coffee Beans

Adding a trace amount of moisture to your beans offers several practical benefits for your daily coffee routine:
  • Reduces Static and Mess: The friction of grinding generates static electricity. Adding a tiny bit of water neutralizes this charge, preventing coffee grounds from clinging to the grinder, dosing cup, or your countertop. [2, 3]
  • Minimizes Grind Retention: Static causes coffee to stick inside the grinder's burrs and chute. By stopping this cling, more of the coffee you put in comes right back out. This means your dose weights will be highly consistent. [2, 4, 5]
  • Better Consistency and Extraction: Many users on forums like Reddit report that adding water helps prevent clumping, leading to a more uniform grind and better, more even extraction. [2, 3, 6]
· 1970 M01 1

How to Do It

You don't need fancy equipment to use the Ross Droplet Technique: [1]
  1. Measure your dose of coffee beans into a dosing cup or weighing boat.
  2. Spritz a very fine mist of water (usually just 1-3 sprays) onto the beans. Many enthusiasts use a small, inexpensive facial mister.
  3. Alternatively, you can simply run your finger under the tap and stir the beans, or dampen a spoon and mix them so the surface is lightly coated. [1, 2, 4, 7, 8]

Important Precautions

While this technique is widely recommended, it is intended to be used in moderation: [1, 2, 8, 9, 10]
  • Use very little water: Excessive moisture can cause rust on steel grinder burrs.
  • Avoid commercial or integrated grinders: Do not do this with fully automatic bean-to-cup machines or commercial grinders where the beans sit in a hopper, as the trapped moisture can cause beans to clog and damage the equipment. [2, 7, 9]



can these be used on hand grinders?


Yes, the Ross Droplet Technique (RDT) works perfectly on hand grinders. It is highly effective because hand grinders suffer from the same static buildup as electric ones. [1]

Special Precautions for Hand Grinders

While the method is the same, you must take extra care with a manual grinder: [2]
  • Dry the Internals: Water can easily trap inside a hand grinder's compact body.
  • Watch the Bearings: Excess moisture can seep into the ball bearings and cause them to seize.
  • Check Burr Material: Stainless steel resists rust well, but carbon steel burrs will degrade quickly if left wet.
  • Use Minimal Moisture: One tiny drop or a damp finger stir is more than enough for a single dose. [3, 4, 5, 6]

How to Apply It Safely

  1. Weigh your single dose of coffee beans in a separate cup.
  2. Dampen the handle of a spoon or your finger under a tap.
  3. Stir the beans thoroughly to distribute the moisture evenly.
  4. Pour the beans into your hand grinder and grind immediately. [7]
If you want to make sure your specific setup is safe, let me know:
  • What brand or model of hand grinder do you use?
  • Do you know if your burrs are stainless steel or carbon steel?
I can tell you exactly how durable your grinder is against moisture.



timemore chestnut C3 ESP Pro

 

Yes, you can absolutely use the Ross Droplet Technique (RDT) on your Timemore Chestnut C3 ESP Pro. Because this specific model is designed for fine espresso grinding, it suffers from significant static buildup, making water droplets a great solution. [1, 2, 3]
Your grinder is highly compatible with this method for several key reasons: [4]
  • Rust-Resistant Burrs: Your grinder uses S2C660 stainless steel conical burrs. Unlike carbon steel, stainless steel handles minimal humidity safely. [1, 5, 6]
  • All-Metal Interior: The ESP Pro features an upgraded all-metal aluminum alloy and stainless steel build with no internal plastic parts. This means no plastic gaps to warp or hold onto damp grinds. [7, 8, 9]
  • Low Retention Design: The C3 ESP Pro already has a very low natural grind retention (losing only about 0.1g per dose). Adding RDT ensures that even that tiny fraction drops straight into your catch cup. [3, 10]

Safe RDT Practice for Your Grinder

To prevent fine coffee dust from turning into mud and clogging your espresso adjustment dial: [2, 11]
  1. Limit to 1 Spray: Use a tiny spray bottle to mist your beans just once. If you don't have a spray bottle, use the "wet spoon handle" trick to stir your beans.
  2. Shake Well: Toss the beans around in your dosing cup so the single droplet spreads evenly across all the surfaces.
  3. Do Not Store Wet: Grind the beans immediately after moistening them. Never leave damp beans sitting in the grinder hopper.
  4. Regular Brushing: Use the cleaning brush included with your C3 ESP Pro to clear out the burr area every few days. [2, 3, 11, 12]
If you are using it for espresso, would you like recommendations on the best click range settings for dialing in your shots, or tips on how to deep clean the burrs?


yes to both

To get the absolute best results from your Timemore Chestnut C3 ESP Pro, you need to understand its distinct adjustment system and follow strict dry-cleaning habits. Unlike the standard C3, the ESP version features an extra-fine pitch dial designed specifically to handle micro-adjustments. [1, 2, 3]

1. Recommended Click Range Settings

The C3 ESP Pro uses a 30-click-per-rotation dial, with each click moving the burrs by a precise 23.3 microns. The markings on your dial show standard numbers (0 to 9), but you can count the clicks between them. [1, 4, 5]
  • Espresso (Standard / Non-Pressurized): 24 to 28 clicks (roughly 0.8 to 0.9 total rotations from zero).
  • Espresso (Pressurized Basket): 28 to 33 clicks (around 1 full rotation).
  • Moka Pot: 30 to 42 clicks (1.0 to 1.4 total rotations).
  • Pour Over / V60: 42 to 60 clicks (1.4 to 2.0 total rotations).
  • French Press / Cold Brew: 60 to 90 clicks (2.0 to 3.0 total rotations). [2, 5, 6]
Note: Never run the grinder between 0 and 15 clicks. Grinding at extremely low settings causes the stainless steel burrs to rub together, which will prematurely dull or chip the cutting edges. [7, 8]

2. How to Deep Clean the Burrs

Do not use water, soap, or liquids to clean your grinder, as trapped moisture inside the central axle assembly will damage the internal ball bearings. Perform a deep clean once every few weeks to remove built-up coffee oils. [3, 9, 10]

Step-by-Step Disassembly & Cleaning

  1. Find True Zero: Flip the grinder upside down, attach the handle, and rotate the dial clockwise until it stops clicking. Do not force it. [5, 11]
  2. Unscrew the Dial: Twist the adjustment plate counter-clockwise until it completely detaches. Hold the central shaft steady from the top so it does not spin. [3, 11]
  3. Remove Components: Carefully pull out the inner cone burr, the metal spring, and the flat washer beneath it. Lay them out on a clean towel in the exact order they came out. [11]
  4. Dry Brush and Blow: Use your Timemore cleaning brush to scrub compacted coffee dust out of the inner and outer burr teeth. A camera lens rocket blower is highly effective for clearing out stuck fines from the main aluminum body. [2, 3, 12]
  5. Reassemble Correctly: Push the central shaft back through the top. Drop the washer back onto the shaft (flat side against the bearing). Slide the spring on, followed by the inner burr. Screw the adjustment dial back on clockwise until it locks back at zero. [11]
If you would like, I can give you a breakdown of how to adjust your coffee dosage to compensate for the gaps between clicks when fine-tuning your espresso shot. Would you find that helpful? [13]




yes please

When fine-tuning espresso with a stepped hand grinder like the Timemore Chestnut C3 ESP Pro, you will sometimes find that one click is a little too slow, but the very next click is a little too fast.
Because each click moves the burrs by 23.3 microns, you can bridge these gaps by adjusting your coffee dose (the weight of the dry coffee grounds) rather than changing the grind size.

The Golden Rule of Dose Adjustments

  • To slow a shot down (increase extraction time): Add more coffee to the basket.
  • To speed a shot up (decrease extraction time): Reduce the amount of coffee in the basket.

Step-by-Step Micro-Tuning Guide

If your target recipe is 18 grams of coffee yielding 36 grams of espresso in 30 seconds, follow these exact steps when you get stuck between clicks:

Scenario A: Your shot is too fast (e.g., 22 seconds at 26 clicks)

  1. Do not change the grind size to 25 clicks (which might make it too slow).
  2. Keep the grinder at 26 clicks.
  3. Increase your dry dose by 0.2g to 0.5g (grind 18.3g or 18.5g of coffee).
  4. Keep the target yield the same. The extra coffee creates more resistance, slowing the water down to hit your 30-second target.

Scenario B: Your shot is too slow (e.g., 38 seconds at 25 clicks)

  1. Keep the grinder at 25 clicks.
  2. Decrease your dry dose by 0.2g to 0.5g (grind 17.7g or 17.5g of coffee).
  3. The slightly thinner coffee bed allows water to pass through faster, bringing your shot time down.

Critical Limitations to Keep in Mind

  • Basket Capacity: Never exceed or drop below the physical limits of your portafilter basket by more than 0.5 grams. Packing a basket too full will cause the coffee puck to press against the espresso machine's shower screen, causing channeling.
  • The 0.1g Scale: You must use a digital scale that measures down to 0.01g or 0.1g. Standard kitchen scales are not accurate enough to measure these micro-adjustments.
If you are currently dialing in a specific bag of coffee, let me know what machine you are using and your current shot times, and we can calculate the exact adjustment together!


Delonghi ECP33.21.BK Espresso Machine. 20 seconds for 12 grams on non-pressurised basket.also, do you have the manual for my timemore chestnut C3 ESP Pro?


Here is your diagnostic plan for your DeLonghi ECP33.21.BK shot, followed by the original manual documents for your Timemore Chestnut C3 ESP Pro. [1]

1. Espresso Diagnostics: 20s for 12g (Unpressurized)

Your current shot is running way too fast, which causes under-extraction (sour, thin, watery espresso). A 12-gram dry dose is quite low for a standard non-pressurized double basket, which creates less physical resistance for the water. [2]

Step 1: Up Your Dose (Highly Recommended)

Most standard unpressurized 51mm double baskets for the DeLonghi function best with 14 to 16 grams of coffee. [3]
  • The Problem: Your 12g dose creates a thin puck. The water from the DeLonghi's 15-bar pump punches right through it in 20 seconds.
  • The Fix: Increase your starting dose to 14.0 grams if your basket has room. This instantly thickens the coffee bed, slows down the water, and increases extraction time. [4, 5]

Step 2: Grinding Finer on the C3 ESP Pro

If you increase the dose to 14g and the shot still finishes under 25 seconds, your grind is too coarse.
  • Action: Adjust your C3 ESP Pro finer by 2 to 3 clicks (move clockwise toward zero, then count back out).
  • Goal: You want to restrict the water flow until you achieve a standard 1:2 ratio (e.g., 14g of coffee grounds yielding 28g of espresso liquid in 25 to 30 seconds). [6]

2. Timemore Chestnut C3 ESP Pro Manuals

You can view or download the layout guidelines and operating sheets directly via these digital records:

Core Manual Reminder for the "ESP" Dial System

The manual notes that the ESP model dial counts by rotations (circles) rather than just single clicks: [6, 9]
  • 1 Full Circle = 30 individual click notches.
  • The factory starting point recommendation printed in the manual for espresso is 0.8 to 1.1 total circles out from absolute zero (which equals roughly 24 to 33 clicks). [6, 10, 11]
Would you like me to guide you on how to check if your 14g dose will fit safely inside your portafilter basket without hitting the machine's shower screen?



yes. also, I'm using a 0.2mm puck filter.

 

Using a 0.2mm puck screen (puck filter) is a great choice for the DeLonghi ECP33.21.BK. It distributes the water evenly and keeps your machine's shower screen completely clean. [1, 2, 3]
However, because the puck screen takes up physical headspace inside the basket, you must test your basket capacity carefully to avoid channeling (where water cracks the puck, causing the fast 20-second shots you are experiencing). [1, 2]
The "Coin Test" for Basket Clearance
To check if your new 14-gram dose fits safely with your 0.2mm puck screen, use this simple trick:
  1. Prep the Basket: Fill your portafilter with 14.0 grams of coffee grounds. Tamp it firmly and evenly.
  2. Place the Screen: Lay your 0.2mm puck screen flat on top of the tamped coffee. [1]
  3. Add a Coin: Place a small coin (like a 10-cent or 20-cent piece) directly on top of the puck screen. [1]
  4. Lock and Check: Lock the portafilter into your DeLonghi group head completely, then immediately remove it without brewing any water. [1]
  5. Inspect the Impression:
    • If the coin is pressed deeply into the puck screen: Your 14g dose is too high. The coffee is hitting the machine's shower screen, which will cause the puck to crack and leak water too quickly. Drop the dose to 13.5g.
    • If there is no impression, or just a very faint outline: Your 14g dose is perfect. [1, 2]
How Your 0.2mm Screen Changes Your Grind
Because a puck screen adds a layer of resistance, it slightly slows down the water flow on its own. [1, 2]
  • The Strategy: First, fix your dose weight using the coin test. Once your dose is locked in (aim for 14g if it fits), use your Timemore C3 ESP Pro to fine-tune the time. Drop the grinder 1 click finer at a time until your 14g dose yields 28g of espresso in 25 to 30 seconds. [1]
Would you like help troubleshooting the taste of your espresso (sourness vs. bitterness) once you hit that 25-to-30-second target?

yes please

Once you hit that 25-to-30-second target with your 14g dose, you have successfully fixed the water flow. Now, you use your tongue to make the final micro-adjustments based on taste.
The two main flaws you will encounter are sourness (under-extracted) and bitterness (over-extracted). Here is how to fix them using your Timemore C3 ESP Pro and the DeLonghi ECP33.21.BK:

1. If Your Espresso Tastes Sour, Sharp, or Vinegary

  • The Cause: The water did not extract enough sweet and bitter compounds from the coffee to balance out its natural fruit acids.
  • The Fix: You need to increase extraction. Go 1 click finer on your Timemore grinder (e.g., move from 26 clicks down to 25 clicks). This will push your shot time closer to 30 or 32 seconds, unlocking sweetness and body.

2. If Your Espresso Tastes Bitter, Ashy, or Dry

  • The Cause: The water extracted too much from the coffee, pulling out the heavy, unpleasant, bitter compounds at the very end of the shot.
  • The Fix: You need to decrease extraction. Go 1 click coarser on your Timemore grinder (e.g., move from 26 clicks up to 27 clicks). This will speed up the shot by a couple of seconds, cutting off the bitter end of the extraction.

3. The "DeLonghi Special": Temperature Surfing

Because the DeLonghi ECP33.21.BK uses a small boiler without precise digital temperature controls (a PID), the water temperature fluctuates wildly. If your grind size feels perfect but the taste is inconsistent, try this routine:
  1. Wait for the "Ready" light to turn on.
  2. Turn the dial to the steam icon for exactly 5 to 7 seconds (do not let it pump water). This tricks the boiler into heating up to a higher, more stable temperature perfect for extraction.
  3. Immediately switch the dial back to the brew position to pull your shot. This prevents sourness caused by water that is too cold.
What type of coffee beans (light, medium, or dark roast) are you currently brewing? Knowing the roast level will help us target the exact flavor profile you should be aiming for.



medium


Medium roast coffee is arguably the most rewarding roast profile to dial in, but it can also be the trickiest. It sits perfectly between the bright acidity of light roasts and the heavy bitterness of dark roasts.
When brewing a medium roast on your DeLonghi ECP33.21.BK, your goal is to balance pleasant fruit acidity with rich, sweet caramelized flavors (like milk chocolate, nuts, or brown sugar).

Golden Rules for Medium Roasts

Because medium roasts are moderately dense, they require careful extraction parameters to avoid tasting either overly sour or aggressively hollow:
  • Target a 1:2 to 1:2.2 Ratio: For your new 14g dose, aim for a liquid espresso yield of 28g to 31g in your cup.
  • Target Time: Aim for 27 to 30 seconds. If it finishes faster than 25 seconds, it will taste like sour green apples. If it goes past 32 seconds, the finish will turn unpleasantly bitter and dry.
  • Use the Steam Trick: Medium roasts need a solid amount of heat to extract sweetness. Definitely use the 5-second steam prep trick mentioned earlier to boost your DeLonghi's brewing temperature.

Flavor Tuning Checklist

Once your shot hits 28g–31g in about 28 seconds, taste it and use this quick guide to adjust your Timemore C3 ESP Pro:
If it tastes like...It means...Your adjustment on the Timemore:
Lemon juice, sour, salty, or thinUnder-extractedGo 1 click finer (clockwise) to slow the water down.
Cocoa powder, baking chocolate, or ashOver-extractedGo 1 click coarser (counter-clockwise) to speed it up.
Smooth, sweet, balanced, with a clean finishPerfect ExtractionLock it in! Write down that exact click number.

A Quick Warning on Freshness

If your medium roast beans were roasted less than 7 days ago, they will contain too much trapped carbon dioxide gas. This will cause your espresso shot to bubble aggressively, create a thick but unstable crema, and channel easily. Medium roasts typically peak in flavor and extraction stability between 10 to 21 days after the roast date.
Now that you have your target numbers, are you ready to test out the 14g dose, or would you like to troubleshoot how to properly tamp the coffee evenly in your unpressurized basket first?



tamp the coffee


Tamping is the most critical physical step when using an unpressurized basket. A bad tamp creates weak spots in the coffee bed. Water will rush through these spots (called channeling), making your shot run too fast and taste sour. [1, 2, 3, 4, 5]

The 4 Rules of a Perfect Tamp

Follow these steps to ensure your 14g medium roast dose extracts evenly:
  • Make it Perfectly Level: This is much more important than how hard you press. If your tamper is tilted, water will rush to the thin side. Ensure the metal silver ring of the tamper sits perfectly flat and parallel to the top rim of the basket. [6, 7]
  • Tamp Until the Coffee Stops Compressing: Press down firmly until the coffee bed completely resists your hand. You do not need to press with massive force—once the air is squeezed out of the grounds, pressing harder does absolutely nothing. [8, 9, 10, 11, 12]
  • Keep Your Wrist Straight: Stand over the portafelter so your elbow is bent at a 90-degree angle. Press straight down using your body weight, not your wrist muscles. This prevents uneven tilting. [13, 14, 15, 16, 17]
  • Do Not Knock the Portafilter: Never tap the side of the portafilter with your tamper after you finish pressing. Doing so breaks the seal between the coffee puck and the metal basket walls, which causes instant water channeling. [18, 19, 20]

A Note on the Stock DeLonghi Tamper

The plastic spoon-tamper that comes in the box with the DeLonghi ECP33.21.BK is notoriously difficult to use. Because it is made of flexible plastic and is slightly smaller than the 51mm basket, it easily creates an uneven, messy tamp. [21, 22]
If you are still using the stock plastic tool, upgrading to an inexpensive 51mm heavy metal tamper (or a spring-loaded leveled tamper) will instantly make your espresso shots consistent.
Give this level tamp a try with your new 14g dose and 26-28 click range. Let me know:
  • Did the shot slow down closer to your 25-30 second target?
  • How did the taste change compared to your old 12g shot?
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