Cold blooming in the preparation of filter coffee

At what temperature do you let your favourite coffee bloom in the dripper? 80 °C? 90 °C? 94 °C? What if I told you: "try it with water as hot as the tap," or "try throwing a few ice cubes on the dripper." Yes, today it's about cold brew and how it affects the final taste of the coffee.


If you're a coffee geek with an internet connection - which you are, or you wouldn't be reading us - you may have come across avideo a while back in which Vincent Wong, head roaster and owner of Tales Coffee, talks about what cold blooming is and how he came up with it.

Watch the video about cold blooming

How did cold blooming come about?

Back in 2015, when Vincent started working with select coffees, he had one roastery in his area. It was always roasting beans much darker than Vincent would have liked. He could never get the flavour he wanted. At the same time, bitter notes always dominated the taste of the coffee he prepared.

Once, sitting in a café drinking hot lemon tea, he realized that if he poured boiling water over honey or lemon, they would turn bitter. And if teahouses can let tea bloom at lower temperatures to protect it from releasing tannins, why couldn't he let coffee bloom at a similar temperature or even lower? And cold blooming was a thing of the past.

Tales Coffee Cafe and Roastery |

Recipe for filter coffee using cold blooming

You will need:

  • 20 g of coffee ground to medium coarseness
  • 75 g room temperature filtered water
  • 225 g filtered water at 98°C
  • Dripper with filter rinsed with hot water


  1. Pour the coffee into the dripper and cover with 75 g of cold water.
  2. Stir briefly and quickly.
  3. After 20 s, start adding 225 g of hot water in a slow, circular motion.
  4. Finally, stir the coffee gently.
  5. The total time should not exceed 2:30.

You may be surprised by the tones in a coffee prepared in this way. Vincent Wong himself admits that you won't get the flavours you are used to from coffee prepared in this way. On the other hand, it will give you something you might not expect in a coffee you already know. Try it and judge for yourself. Enjoy.

Our cold blooming test

In order not to sell you a bill of goods on the Spa Coffee blog, my colleague Mirka sacrificed herself and tried cold blooming on herself.

She prepared three batches of the same coffee, three cups and one recipe. The only thing that made the recipes different was the temperature of the water used in the pre-infusion.

In one case it was ice water from the fridge (about 6°C), in the second casecold water from the tap (about 17°C) and in the third casehot water - as always. And how did it turn out?

Ice water

In the case of blooming coffee with ice water, as you might expect, the aroma in the coffee did not fully develop. While there was no bitterness, there were hints of sweetness and medium notes. Overall, however, the flavour of the coffee was flat. "A weak and too mild coffee."

Cold water

If we use tap water (filtered, of course), our test only starts to get interesting. The same coffee as in the previous case showed a pleasant sweetness and acidity. The taste was fuller with a hint of bitterness in the aftertaste. Overall, the flavours melded nicely in the coffee and the coffee rounded out nicely. "Such a coffee lime." ????

Hot water

The hot water during blooming caused what we all probably know. The coffee had a strong aroma, a strong flavour with bitter notes. Yet it had a noticeable sweetness and acidity. Overall, it had a much tighter flavour profile. "It is advantageous to wait until it cools down a little. Then the sweet notes come out more."

Jaký vliv má teplota vody při bloomingu vliv na výslednou chuť kávy


What coffee is best for cold brewing?

Try any of our filter-roastedcoffees.

Can I try cold blooming on a French press?

Of course. Chemex, smart, French press. It's still practically the same preinfusion.

What's the difference between a cold bloom and a cold brew?

Cold brew is coffee that is completely cold brewed over an extended period of time (even tens of hours). In cold brewing, you just let the coffee bloom cold, but you continue to prepare it in the classic way - pouring hot water over it.

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