Made in the USA by Think Crucial
Descaler for Fellow Kettles & Aiden Brewer, 15 Uses
Shipping
Free U.S. shipping on every order
Dispatch
Ships same business day when ordered by 2pm ET
Works
Not sure? Ask us before you order
Returns
Unopened bottles: 30-day returns
What's in the box.
Exactly what ships.
In the box1 line
- 1 ×8 fl oz bottle30% citric acid concentrate, 15 descales
- Size
- 8 fl oz
- Contains
- Citric acid, sodium citrate, water — unscented, no dye
- How often
- Monthly
- Made by
- Think Crucial (not affiliated with Fellow)
Think Crucial vs. Fellow's own.
We only quote the other brand's price once we've checked it and can show you where.
| What | Think Crucial | Fellow's own descaler |
|---|---|---|
| Cost per use | About $1.47 (15 uses) | Not quoted |
| Price | $21.99 with free U.S. shipping | Not quoted |
| If it doesn't work | Ask us before you order | Fellow's own terms |
| Made by | Think Crucial | Fellow |
Made by Think Crucial for the machines listed. It isn't made by or affiliated with Fellow. Always follow your machine maker's own descaling instructions.
How to use it.
- Add
Add 1 tablespoon of concentrate to the kettle or reservoir and fill with water.
- Heat
Heat, then let it stand 15 to 30 minutes.
- Rinse
Empty and rinse thoroughly.
- Flush
Run one full cycle of clean water and discard it before brewing.
What owners say.
On thinkcrucial.com
No reviews of this bottle on thinkcrucial.com yet. Bought one? Tell the next person whether it fit and how it's doing.
Write the first review
On Amazon
5.0 out of 5 from 10 ratings on Amazon (as of Oct 1, 2026)
Ratings and reviews from Amazon.com for the same Think Crucial product, as of Oct 1, 2026. They are separate from reviews on this site and aren't counted in them.
Before you order.
Shipping, returns and fit work the same on every product.
Q01Will it work with my machine?
Email support@thinkcrucial.com with the model number from your machine's label before you order, and we'll tell you whether it suits it.
Q02Is this Fellow's own product?
No. It's made by Think Crucial. Think Crucial is not affiliated with Fellow. Always follow your machine maker's own instructions.
Q03What if it doesn't work, or I change my mind?
Unopened bottles can be returned within 30 days of delivery. For safety we can't take back opened bottles.
Q04When will it arrive?
Shipping to U.S. addresses is free on every order. It ships the same business day when you order by 2pm ET, and arrives in 2–5 business days.
Q05Is there a subscription?
No. You buy one when you need one. Nothing renews and nothing auto-ships.
We make what we sell.
Think Crucial started in 2007 at a family vacuum repair shop. Today we make our own descalers and cleaners here in the USA, plus aftermarket filters, bags and parts. Each one says what it's for.
- Find the model number on the rating label
- Match it to the list on this page
- Not listed? Ask us before you order
Ready to order
Descaler for Fellow Kettles & Aiden Brewer, 15 Uses
$21.99Free U.S. shipping
Unopened bottles: 30-day returns.
Full product description
Fellow recommends citric acid descaling for its kettles. This is that chemistry, in a clear unscented concentrate, at a bottle size that lasts.
Three ingredients — citric acid, sodium citrate, water. No fragrance and no dye, which matters when the thing you are descaling is the kettle you brew filter coffee with. One tablespoon per descale, 15 descales per 8 fl oz bottle.
Features:
- Fits every Fellow kettle and the Aiden brewer – Stagg EKG in all colours and wattages, EKG Pro, EKG Pro Studio, Corvo EKG, the Clyde electric kettle and the Aiden Precision Brewer.
- 15 uses per bottle – One 8 fl oz bottle delivers 15 full descale cycles at the recommended 1-tablespoon dose — over a year at monthly descaling.
- Unscented and clear – No artificial fragrance and no dye. Citric acid, sodium citrate and water, and nothing else.
- The chemistry Fellow recommends – 30% citric acid concentrate, dissolving instantly rather than needing to be mixed from powder.
- Restores heat performance – Clears limescale from the heating element so temperature accuracy and heat-up time return to normal. Made in the USA.
How to use:
- Add 1 tablespoon of concentrate to the kettle or reservoir and fill with water.
- Heat, then let it stand 15 to 30 minutes.
- Empty and rinse thoroughly.
- Run one full cycle of clean water and discard it before brewing.
Why Think Crucial:
- US-based, family-owned brand serving over 1,000,000 households since 2007
- Replacement parts, filters and cleaning solutions for commonly used appliances
- Customer support available if a product does not perform as described
Think Crucial is an independent brand. Brand and model names are used to show compatibility only; this is a Think Crucial product, not made by the appliance manufacturer. If it doesn't work with the machine we list, email us and we'll refund it. Always follow your appliance manufacturer's own cleaning and descaling instructions.
How to use it: see our step-by-step guides: How to descale an electric kettle, How to descale a coffee maker (Keurig, Nespresso, De'Longhi).
Brand and model names are used only to show compatibility. Think Crucial is an independent brand, not affiliated with those manufacturers. Always follow your machine maker's own descaling instructions.