La Marzocco Linea Micra - pre brewing + basket dose recommendation

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#1: Post by haber123 »

Hi all
i own la m micra + option lagom p64 grinder.

1. what is your recommendation setting time for pre brewing on/off ? i usally use 3sec on and 5 sec off. but i have read that its not recommended to use "on" for more then 2 sec.

2. i have vst 18g basket and LM 17G basket. when i dose 18g in my 18g vst basket i get screw mark prebrewing, something that can cause uneven extraction.

what is your dose recommendations ? i think that with la marzocco i need to under dose about 1g of what is written on the basket

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#2: Post by Jake_G »

Hi David,

Welcome to HB!
haber123 wrote:i usally use 3sec on and 5 sec off. but i have read that its not recommended to use "on" for more then 2 sec.
The recommendation is based on not having build in the group and then release. Check the left side of the drain box while brewing. If there is a release of water into the box after your 3s prebrewing, try 2 instead. In either case, taste wins over any sort of dogma preached here. Even if it's been preached by me :wink:
haber123 wrote:what is your dose recommendations ?
Dose is highly dependant on roast level and bean density. To check if you are dosing too much, simply lock in the portafilter and the remove it, prior to brewing a shot. A light witness mark from the center screw is fine, and tells you you can't dose much more, if at all. No mark at all means you may be able to increase the dose a bit if you wanted to, and may contribute towards soupy pucks. But again, if the taste is good, all is well. Lastly, if the screw is buried in the dry puck, you would likely get better tasting results with a slightly lower dose.

The best advice I can give you is to explore different doses, yields, grind settings and shot times.

Use the LM 17g basket and actually follow the guide on HB on how to dial in by taste: Espresso 101: How to Adjust Dose and Grind Setting by Taste Drop your dose all the way down to 12g and tighten your grind to get 24g out in around 30s. Taste what you get. Bump the dose up to 14g and loosen the grind a bit to get 28g out in around 30s. How does this taste compared to 12g? Better? Worse? Why? Keep going till you find the max dose that fits in your basket.

Then start over at 12g dose and try extracting 30g out in around 30s. Try 14g in and 35g out, 16:40, and so on. Then try 25s or 20s shot times. Explore how things taste. Then try 35 or 40s shot times.

There is no recommended dose for your tastes. Only starting points. You need to explore what the machine has to offer with the coffees you prefer.

Hope this helps,


- Jake
LMWDP #704
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haber123 (original poster)

#3: Post by haber123 (original poster) »

What you mean is that I need to check that there is no water going to the drain when the 3 sec is over and the machine enters the off (waiting phase) ?

But always excess water will go to the drain ? So I don't understand it

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#4: Post by Jeff »

You don't want any more water than what it takes to wet the puck. You don't want to pressurize the basket so it doesn't depressurize at the end of prebrew.