CremaLoop Blog

How We Built the Slow Feeder Metal

Premium materials, smarter features and USB-C charging were the top three wishes from our customers. Here is how we turned them into the Slow Feeder Metal.

Slow Feeder Metal in black and silver

TL;DR

  • After the Slow Feeder Pro, we asked our customers what the next generation should do better. Three wishes stood out: premium materials, smarter features and USB-C charging.
  • Rennan and I spent six months on nothing else: a machined aluminium body, a borosilicate glass container, a custom circuit board, an anti-stall routine and a built-in battery.
  • One charge lasts up to about 20 hours of feeding, roughly 1,200 doses.
  • Lance Hedrick tested our first prototype, and his feedback shaped the final product.
  • The Slow Feeder Metal launched in November 2025 and is now in stock.

Starting from the wishlist

Our earlier slow feeders ran on AAA batteries and had 3D-printed bodies. They worked, and they changed how a lot of home baristas grind. But when we asked what would make the next one better, the list was long, and three things came up again and again:

  1. Premium materials that match a high-end grinder.
  2. Smarter features, so the feeder takes care of itself.
  3. USB-C charging instead of disposable batteries.

So we paused every other product launch and spent six months on one thing. Between us, Rennan and I have about 20 years of product development experience, and we used all of it.

Credit where it is due: James Hoffmann and Lance Hedrick did more than anyone to make slow feeding popular. Lance received our first Slow Feeder Metal prototype, and his feedback shaped the final product.

Premium materials

Coffee beans being poured into the glass container of a Slow Feeder Metal
Borosilicate glass, so you can watch the beans go in.
  • Precision-machined aluminium for the housing, for strength and a finish that sits well next to a premium grinder.
  • Borosilicate glass for the bean container: clear and durable.
  • Three colours: matte black, silver and white, to match the grinder you already love.

Smarter: the anti-stall routine

Some beans, depending on roast, size and shape, can occasionally jam a feeder disc. On the Metal, the feeder handles it on its own:

  1. It detects the stall.
  2. It runs a three-step unjam sequence.
  3. It gets the beans moving again automatically.

That took a fully custom circuit board, careful sensor tuning and a lot of programming. We also added a timed auto-off: if you forget to switch it off after grinding, it powers down after about three minutes.

Slow Feeder Metal mounted on a grinder
The Slow Feeder Metal on a grinder.

USB-C power

We replaced the AAA batteries with a built-in 2000 mAh lithium-ion battery that charges over USB-C. One charge gives up to about 20 hours of feeding, which is roughly 1,200 slow-fed doses. For heavy use you can leave the cable plugged in and keep feeding while it charges.

What stayed the same

  • A grinder adapter for more than 40 grinders, included when you order. The Metal is most popular with the Weber Workshops EG-1, Zerno Z1/Z2, Timemore Sculptor 078, DF64 and DF83, Kafatek Monolith and Lagom P80.
  • The optional single dose bellow and lid, which raise the capacity to 100 g and help push out the last grounds.
Slow Feeder Metal with the optional single dose bellow and lid
With the optional single dose bellow and lid.

A launch in waves

We have to be honest: manufacturing a tool like this in small batches is hard. So we launched the Metal in limited pre-order waves, starting with 50 units, to keep quality high from day one. Demand ran ahead of production for months. Today the pre-order waves are complete and the Metal is in stock.

What came after

The Metal became the base for the rest of the range. The Slow Feeder Ultra and the Slow Feeder Pro V2 use the same feeder disc and anti-stall system in lighter, more affordable bodies. And in June 2026 we added machined metal adapters for the Weber Workshops EG-1 and the Lagom 01, the same month a Slow Feeder Metal reached the World Brewers Cup final in Brussels.

The Slow Feeder Metal is designed in Switzerland, in Winterthur.

➡️ Shop the Slow Feeder Metal

➡️ Compare Metal, Ultra and Pro V2

Frequently asked questions

How long does the battery last?

Up to about 20 hours of feeding per charge, roughly 1,200 doses. You can also run it while it charges.

What happens if beans jam?

The anti-stall routine detects the stall and runs a three-step unjam sequence automatically.

Which colours are available?

Matte black, silver and white.

Who tested the Slow Feeder Metal before launch?

Lance Hedrick received our first prototype and his feedback shaped the final product.

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CremaLoop

Feed your grinder slowly.

Slow feeders for more than 40 single dose grinders. Designed in Switzerland.