# Technique after pre-infusion



## Nod (Sep 7, 2013)

I have now fitted the mechanical Pre-infusion for my La Spaz Vivaldi II. It seems to be working ok and seems to have added 6 seconds from pressing the button until the coffee comes out of the group. The question is.. Should I be changing my coffee making schedule? I used to dose 18gr and aim for 28gr ish espresso in 26-28 seconds? Do I now just make it 18gr for 28 gr ish in 33-34 seconds? Or I wondered whether I should be aiming for less time as maybe Preinfusion time counts some time towards the extraction time? I have not had much time to be playing with it but though I would post in case anyone had an ideas. thanks


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## Mrboots2u (May 10, 2013)

Same dose same grind

A shot with a portion of pre infusion will extract the same brew ratio over a quicker time

The longer the pre infusion the quicker the resulting extraction

Pre infusion allows you to grind a bit finer , to get a higher extraction yield ( tastier shot )

Caveat i dont how know pre infusion works on your machine

Doesn't answer your question re time....

But id be grinding a bit finer letting the shot run longer ( include your infusion time might get you to 30-35 seconds ) and tasting to see how the shot is .....

Some people count pre infusion time at half its elapse and add it on to the extraction time

6 seconds pre infusion = 3 seconds ( i dont do this )

Interestingly machines with shot clocks built in ( GS3, Vesuviius etc ) run from when the lever , button is pressed ( includes pre infusion time )

I dont tend to get hung up on the time too much nowadays ( unless its a 15 second shot or a 50 seconds ) , i adjust via taste and sometimes vst where needed.


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## Mrboots2u (May 10, 2013)

IF your shots taste ok as they are though , ignore my ramblings above......


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## Nod (Sep 7, 2013)

thanks a lot Boots - that is very helpful. I will experiment with longer and shorter shots when my 3 kilos of foundry arrive. I tried tightening the grind today and it did seem to make a much nicer tasting drink...

again, i appreciate the expertise and advice

cheers


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## jjprestidge (Oct 11, 2012)

If it's progressive preinfusion, you should aim for a slightly longer extraction time than with a straight 9 bar extraction. This is recommended by quite a few people in the industry, including Scott Rao (with whom I don't always agree, but do in this instance).

JP


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## Nod (Sep 7, 2013)

\ said:


> If it's progressive preinfusion' date=' you should aim for a slightly longer extraction time than with a straight 9 bar extraction. This is recommended by quite a few people in the industry, including Scott Rao (with whom I don't always agree, but do in this instance). JP[/quote']
> 
> Thanks JP. I was doing 28 seconds. Now it takes 6 seconds before any espresso comes out of the group. What do u therefore think should now be my ball park total extraction time... ?
> 
> Pre-infusion has definitely made the process much harder and I am now getting more duff shots. Today I made 2 espresso with the hasbean secret stash Bolivian. I went tight on the grind and allowed a longer extraction time... 35-40 seconds and it was rank.. Totally bitter and horrible. I am guessing I should be aiming to get extraction done in 29-31 seconds. Thoughts?


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## Mrboots2u (May 10, 2013)

Id revert the shot back to 28 seconds and taste , if happy all good...

If bitter , coarsen and make the same brew ratio in less time

What was the brew ratio anyway

If its really worse and more complicated than before then disable the pre infusion


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## ronsil (Mar 8, 2012)

You can set the pre-infusion time on the Vivaldi II.

Ignoring all the current trends with EK43 & Vesuvius combos, I used to work the La Spaz with as little as 3-4 seconds pre-infusion.

Thus 20g in 28 g out for 29-30 seconds. With the Versalab try that formula for starters.

Its a very different kettle of fish with the EK. Usually much longer extraction times.


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## jjprestidge (Oct 11, 2012)

Nod said:


> Thanks JP. I was doing 28 seconds. Now it takes 6 seconds before any espresso comes out of the group. What do u therefore think should now be my ball park total extraction time... ?
> 
> Pre-infusion has definitely made the process much harder and I am now getting more duff shots. Today I made 2 espresso with the hasbean secret stash Bolivian. I went tight on the grind and allowed a longer extraction time... 35-40 seconds and it was rank.. Totally bitter and horrible. I am guessing I should be aiming to get extraction done in 29-31 seconds. Thoughts?


35 seconds sounds a bit too long. Try around 30.

What are your input/output weights?

JP


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## Nod (Sep 7, 2013)

I am weighing in 18gr of ground coffee into the portafilter and aiming for 28 grams of coffee of weighted espresso..

when you say try 30 do you mean total extraction time, including hte 6 seconds of pre-infusion? thanks JP.


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## jjprestidge (Oct 11, 2012)

Nod said:


> I am weighing in 18gr of ground coffee into the portafilter and aiming for 28 grams of coffee of weighted espresso..
> 
> when you say try 30 do you mean total extraction time, including hte 6 seconds of pre-infusion? thanks JP.


Aim for 36g in 30 seconds from when you hit the brew button. 28g is likely to be at the lower end of acceptable extraction yields; pulling it a bit longer may have a positive effect.

JP


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## Nod (Sep 7, 2013)

Thanks a lot... I will look forward to trying this tomorrow.... Cheers


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## jjprestidge (Oct 11, 2012)

Nod said:


> Thanks a lot... I will look forward to trying this tomorrow.... Cheers


So, how did it go?

JP


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## Nod (Sep 7, 2013)

\ said:


> So' date=' how did it go? JP[/quote']
> 
> Thanks for the follow up JP. Away all weekend in the end but I have a kilo arriving tomorrow so will be into it and reporting back after next weekend. I did email Chris coffee and their advice was that the pre-infusion should not alter the shot time at all I.e. No change to extraction time. I think all up I'll add 3 seconds (half pre-infusion time) and go for 30 seconds as u suggest - also coffeechap's view.


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