Kruve: micrometrically precise grinding

We all know how important consistent grind accuracy is when making coffee. In today's article, we're going to introduce the Kruve Sifter - a sieve that will ensure your coffee always has a full and consistent flavour. Read on to find out much more.

The Kruve Sifter - what is it?

It's asystem of sieves that sorts ground coffee, allowing for a more perfect taste ofthe resulting beverage. It works on the principle ofremoving large or small particles and dust that form after the coffee has been ground. This is because even the best coffee grinders do not grind coffee 100% evenly and consistently.

TheKruve sifter has two levels of sifting. Each sieve is designed to sift through beans of a specific size to separate out unwanted particles.

  1. The sieve with the larger holes belongs to the upper section.
  2. The sieve with smaller holes is in the lower chamber.

You pour the ground coffee into the upper part, close it and start sieving. The particles that aretoo large will stay in the top section and thefinerones will fall into thebottom section. The coffee grounds will get trapped in the middle, which should be absolutely perfect for your chosen coffee brew .

???? What else from Kruve? Kruve products are not only strainers, but also other coffee accessories such as aesthetically and above all functionally perfect glass cups for coffee.????

Types of Kruve strainers

There are three models of Kruve sifter:

  • Sifter base,
  • Sifter plus
  • Sifter max.

Each model differs in the number of sieves available. The sizes of each sieve are given in micrometers (0.001 mm).

The Sifterbase modelhas five sieves in the following sizes:

  • 300 μm
  • 500 μm
  • 800 μm
  • 1100 μm
  • 1400 μm

The Sifter plus has 15 sieves ranging from200 to 1600μm (fineness increases in 100 μm increments), which give you even greater screening accuracy .

The last model, the Sifter max, is best for those whonot only grind their own coffee but alsoroast it themselves. As it has 15 sieves for ground coffee and 10 bean sieves, thanks to which you can remove defects from roasted beans.

What does "boulders & fines" mean in ground coffee?

These two terms are used in conjunction with thecoarseness of the ground coffee. Fines (fine particles) are caused by the fragility of the coffee. Boulders (larger particles, stones) are large pieces of beans that can pass through the grinder without being crushed. These particles are almost always formed after the coffee has been ground.

Thebalance between fine and larger particles needs to be maintained. Because these excess particles make the taste change considerably. The fine particles are responsible for the coffee having a "muddier" tasteafterwards and are overextracted. Larger particles, on the other hand,do not impart enough of their flavour to the coffee .

Typical particle size distribution curve. Source

How the homogeneity of the grind affects the taste of the coffee in the cup

There is a great advantage to using a Kruve strainer to influence the consistency of the coffee grind. You will achieve beans that are neither bigger nor smaller than you want. Thus, your coffee will be extracted at the same rate. And you can experiment with different variables.

In his article,Scott Rao investigated which types of coffee brewing are fine particles okay and which are detrimental, and came up with an interesting result.

If you want to make the best filter coffee possible, you need to minimize fine particles as much as possible.

This is because fine particles over-extract and contribute to the bitterness and astringency of the resulting cup. If you remove these particles, you will end up with a cleaner and sweeter cup of coffee.

But as far as espresso is concerned, fine particles are fine to a certain extent, given that espresso requires fast extraction. The fine particles increase the surface contact of the coffee with the water, which can help the extraction. At the same time, excessive amounts of them can clog the portafilter strainer in contrast to the flow of water through the coffee.

Scott Rao's tips for reducing "fines" in ground coffee:

  • Use sharp grinding blades,
  • make sure the grinding blades are as level as possible,
  • grind coarser
  • use larger blades in the grinder
  • sieve and remove fine particles
  • grind hotter grains or use a heated grinder.


The Kruve shifter coffee sieves, which remove excess particles from the ground coffee, are a revolutionary tool to achieve not only a perfectly precise grind. You can also use the strainers as a calibration tool to set your grinder correctly, as you know the exact size of the ground beans. With these strainers, you'll already be enjoying the taste of your top choice coffees, just as they should really be. Get yours too!

Kruve guide

A reference chart for the correct grind size for different types of coffee preparation. Source

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