JonDent - Exploring Electronic Music: gaggimate

Showing posts with label gaggimate. Show all posts

Wednesday, 16 April 2025

Cremina lever profile (for darkly roasted beans)

The Olympia Cremina is a classic lever machine.

It doesn't have a spring.

Like most lever machines it exhibits a declining pressure profile.

This profile is a long shot ... about 45sec.

It uses a fine grind.

With dark roasted beans most of the flavour comes out early in the shot.

Towards the end, the shot is quite watery.

The Cremina uses a narrow 49mm basket.

It is characterized by a manual pre-infusion, a pressure ramp-up, and a subsequent pressure decline, all managed by the user's interaction with the lever.

I have a La Pavoni Europiccola which is quite similar.

I like to start the shot when the machine's group head is around 85C.

The end of the shot usually sees the group temp rising over 90c ... sometimes getting to 92-93c.

The classic La pav basket is 14g so you'd aim for 28 out.

Key Aspects of the Cremina Espresso Profile:

Pre-infusion:

The user initiates a pre-infusion phase by gently lifting the lever, allowing water to gently saturate the coffee puck at a lower pressure.

Here the pressure rises to about 1 bar.

Ramp-up:

As the lever is further depressed, the pressure increases, typically ramping up to a peak pressure as the piston moves through the brew group. (9 bar though I usually hit around 6-8 bar on my La pavoni)

Pressure Decline:

The user manages the lever's movement to control the pressure, causing a gradual decline towards the end of the shot.

This is a really flexible profile.

You can pull this as a 1:1 ristretto for that classic Italian shot.

Sometimes I end the shot early at 30secs but you can also pull this with 12g still at 45 secs.

These lever shots always finish at very low pressures.

This is a screen shot of a lever profile I have loaded into my modded (Gaggimate)

Rancilio Silva.

Red: Temp

Blue: pressure

Green: Flow

The flow peaks twice at 4g/s but drops to 1g/s

I was using a 58mm to 49mm stepdown basket.

It has a Cremina Lever profile.

The initial dose is 18g.

grinder: DF64V (grind setting 15).

Out : 36g

Phases

A preinfusion for 25 secs (zero volume in cup)

- soak - 15s, 1.1bar pressure

- Ramp up to 3 bar, 4 s

- ramp up to 6 bar, 4 secs

- ramp up to 9 bar , 2 secs

There should be no coffee in up at this point.

B. Brew stage (40 secs)

- Ramp down to 8 bar. 10 secs. 6 g volume

- Ramp down to 7 bar, 10 secs, 14 g volume

- Ramp down to 6 bar, 10 secs, 26 g volume

- Ramp down to 5 bar, 10 secs, 36 g volume

The Gaggimate is connected to Bookoo scales via wifi, and the pull shot stops precisely at 36g.

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variation 2

Temp settings:

Higher brew temperatures for lighter roasts, lower brew temperatures for darker roasts

Preinfusion settings:

longer (slower flow rate) preinfusion for lighter roasts,

shorter (faster flow rate) preinfusion for darker roasts

After preinfusion, pressure is ramped up to a maximum and then gradually declines.

Pressure settings:

Max brew pressure of 6-9 bar (I like 8-9 bar)

Adjust decline to maintain a fairly steady flow rate (1.0-1.5ml/s) as puck erodes.

Pour time of ~30s (not including preinfusion)

Use the coffee dose suggested by basket manufacturer (but feel free to updose).

"normale" brew ratio of 1:2 (adjust to your preference)

When starting out, I recommend getting a medium roast house espresso blend from an established specialty coffee roaster. This will maximize your chances of success. Then feel free to branch out to single origin coffees, uber-light roasts, etc.

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Coffee index. Click here :

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Wednesday, 13 November 2024

Classic Italian espresso profile - dark to medium dark roasts

What does it take to make the Classic Italian espresso?

This is a complex question and I'm not an expert. The espresso machines & grinders vary across the country, as does the water and the beans themselves. So the answer depends on lots of factors.

Plus, one can't discount the beauty and richness of Italy itself. Just sitting in a cafe while looking at Roman architecture is bound to elevate the senses.

Italian coffee is often described with words such as rich, thick, chocolate, caramel, toffee, creamy, etc

Generally, Classic Italian espresso machines are set to use "Italian-style" roasted beans (medium dark to dark).

Most machines use the standard “flat 9 bar” profile.

This is a simplified (and in my humble opinion, less good) version of the Lever Profile.

https://djjondent.blogspot.com/2025/04/cremina-lever-profile-for-darkly.html

https://djjondent.blogspot.com/2024/12/spring-lever-pressure-profile.html

Below is a screen shot from a DE1 (decent). It's "classic Italian profile" is :

1. pre-infusion =< 8 sec, ramping from zero to about 4 bar.

Flow at 8ml/sec.

2. Raise the pressure to 9 bar & hold (up to 35 sec)

The pressure doesn't drop. You simply stop the extraction when you receive the dose aim.

(18g in , 36 out in the 1:2 ratio case below).

Flow is limited to 4.5ml/sec.

The temperature throughout is set at 94C, however I like to aim for

88C (for dark/medium beans) to 92C (for light roasts).

It's good to remember that the darker the beans, the more brittle they are.

You have a larger margin for error with dark roasted beans because they are easier to extract.

(the lighter the coffee, the harder to extract).

Water temp and grinder particle distribution is not as important with darker coffees.

With darker roasts there is not as much acidity.

Re grinders,.... many are old, un maintained, use poor beans etc etc.

The baristas don't seem to pay too much attention to weight.

They just quickly dose by time & go.

I think coffee is considered to be a commodity in Italy.

The average price for an espresso is approximately €1.00 to €1.20

(prices like this would make most cafe owners in Australia cry).

I don't think this price has changed for 30 years and the quality has possibly gone down over that time.

Has the percentage of Robusta to Arabica increased over time?

BTW, portion size is usually 7g.

Nobody seems to be willing to pay specialty coffee prices.

Maybe this is because coffee is not grown in Italy .

It seems that lots of bars in Italy are run with a husband and wife team or family members, .... minimising the wages bill ???

This might help to keep costs down (along with a love of cash).

Many cafes use heavy Robusta blends that allow for more crema but also keep the cost down.

I saw a lot of Mazzer Super Jolly grinders being used in cafes in Naples.

These use 64mm flat burrs.

Mazzer and Ceado seem to dominate the Italian market, with Mazzer serving over a million baristas daily.

Ceado being a Venetian-based leader in grinder production is also very popular as are Anfim and Eureka.

With dark roasts, the coarser you can grind the better I think it will be.

You will also get more crema with a coarser grind.

The SCA defines espresso as:

In: Single shot: 7-10g/ double shot 14-20

Out: Single: 10-25g / double: 21-45

Shot time 20-30 secs

Brew ratio: 1:1.5 to 1:2.5

Experiment.:

When you prepare the portafilter, reduce the headspace as much as possible.

To thicken the shot, pull for less time.

To decrease the thickness.. pull for longer or coarsen the grind.

I commonly use this recipe;

I grind a bit coarser, 18g in, 30g out, in about 20 seconds.

My modified Rancilio Silva (Gaggimate) has a "Classic Italian" preset which is similar to the DE1 preset..

This is what the shot looks like. I dosed 18g in and was trying to get 36g out in under 30 secs but it pulled a bit long (36s).

I'll coarsen the grind a bit next time.

I used a DF 64V grinder with the setting at 15.

So I might try 16 or 17 next time.

The Bookoo scales are quite nifty. They connect to the Gaggimate app and the Rancilio via blue-tooth.

I must remember to flush just before I pull the shot to bring the initial temp down a bit.

A video of the shot:

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Coffee index. Click here :

https://djjondent.blogspot.com/2024/03/coffee.html

Wednesday, 3 July 2024

Adaptive profile --- pressure vs flow

An Adaptive Espresso Profile is a modern espresso extraction method that automatically adjusts the water flow rate to maintain a consistent flow after a peak pressure is achieved.

Thus the machine tries to adapt to variations in grind size and puck consistency to produce a balanced, flavorful shot with good crema and mouthfeel.

It uses a strategy of pre-infusing the coffee puck, then building to a specific peak pressure and flow rate within the first few seconds, after which it allows the pressure to decrease while holding the flow rate steady to compensate for changes in puck resistance.

This formula is impt:

Pressure = flow x puck resistance.

They are linked.

The early (analog) lever machines naturally understood this relationship.

You pulled on a spring (loaded at 6 or 9 bar).

My Elektra is loaded at 6 bar.

As the lever went up the pressure slowly decreased from max pressure.

During this time, the flow naturally would also decrease.

And this would compensate for the degradation of the puck over time.

Today, pumped machines keep the pressure at 9 bar even though the puck is degrading.

The result is a increase in flow rate towards the end of the shot with a much more diluted finish.

I think lever machines had it right from the beginning. When you pulled the lever down (in the case of a spring lever) the puck was saturated instantly

(at boiler pressure) reducing the chance of puck unseating, and then a pressure to flow relationship was maintained during the shot pull.

With my E61 machine I'm getting about 7g/sec flow.

It will continue to deliver water to the coffee puck at that rate until it hits 9 bar.

At that point, the OPV will kick in.

Usually the 9 bar level is reached pretty early .. usually at the end of pre-infusion.

The flow rate is probably not 7g/sec. Instead, it will be whatever it needs to be to stay at 9 bar.

This is one of the settings on my Gaggiuino.

Is flow more important than pressure?

Flow is very hard to control.

Resistance is related to the type of grinder, the grind size, roast level, puck integrity, grind solubility, tamp force, distribution, etc

I think that above 10bar, coffee doesn't taste great, so if your focus is on flow

and you accidently touch 10 bar, you risk the coffee failing.

The adaptive setting is very interesting.

Its designed to prioritize the flow rate .... moving it up or down

& adapt it to the chosen grind and dose size..... keeping everything below the peak pressure.

Note that preinfusion is mostly about flow (as there is usually very low pressure).

When discussing flow we usually are focused on the post infusion stage.

So basically, the adaptive profile allows the machine to dynamically adjust the pressure and flow rate during the extraction process.

The machine monitors the resistance of the coffee puck (how easily water flows through it) and adjusts the pressure to maintain a desired flow rate or to reach a target pressure within a specific timeframe.

This means that if the grind is a little too fine and the resistance is high, the machine might lower the pressure to prevent channeling or over-extraction. Conversely, if the grind is too coarse, it might increase the pressure to ensure proper saturation and extraction.

By adapting to the coffee's resistance, adaptive flow profiles can help compensate for variations in grind size, dose, and tamping, leading to more consistent and repeatable results.

How it works

Pre-infusion: The group head fills with water, saturating the puck to ensure even extraction and reduce the risk of puck unseating.

Pressure Peak: The water then ramps up to a high pressure, and the machine finds the optimal flow rate at this peak pressure.

Pressure Drop & Flow Maintenance: After reaching the peak, the profile aims to hold this flow rate constant, even as the machine's pressure decreases due to the puck degrading. This is a key difference from traditional 9-bar profiles, which can lead to increased flow and dilution.

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My Gaggimate also has flow control capabilities.

The GaggiMate controls flow by taking direct command of the espresso machine's pump, using a Solid-State Relay (SSR) to regulate its power, thus controlling the flow.

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Coffee index. Click here :

https://djjondent.blogspot.com/2024/03/coffee.html

Tuesday, 2 July 2024

Blooming espresso profile

Blooming was inspired by pour over drip coffee brewers... releasing CO2 and allowing the grounds to be fully saturated.

It's a great profile for extracting sweetness, esp from lighter roast coffee that is really acidic.

It's a high extraction profile that is also very forgiving.

A big thanks to Scott Rao for all his work.

This profile is exciting from an experimentation point of view as it open's a pathway for extracting

more coffee from less.

I don't usually use a dark roasts with this profile (unless I want my coffee bitter).

I think it's better with light to medium roasts.

You can replicate this on a lever machine.... or any machine that allows you to control flow.

A machine without a OPV (over pressure valve) or a way to override one is an advantage.

This profile has a very long initial pre infusion stage before a flow controlled pressured stage.

Firstly, make sure you grind finer than you would usually for espresso.

I've seen filter paper placed below and above the tamped coffee cake.

These two pieces of paper are supposed to do two things:

1. reduce channeling (top paper) and help dispersion of water over the cake.

2.speed the flow (bottom) as those particles might clog the portafilter. ???

These are just theories so experiment to you heart's content.

Maybe I want to decrease the flow and those fines clogging the portafilter might be a good thing. ...so I sometimes experiment with just the top paper?

I don't like using paper anyway (for environmental reasons) so am experimenting with a puck screen and not using a lower paper filter.

Maybe try using two metal puck screens ?

Method:

1. Ramp the pressure up

to 4 to 6 bar over 10

secs.

Once you hit about 5

bar stop pushing on

your lever (if you're

using a lever machine).

2. You should have let go

of the lever.

This is the blooming

stage where the flow

drops to zero.

The pressure will also drop to zero as water is absorbed into the puck.

If you're using a lever you may see some drops of coffee falling into the cup.

This is OK.

This blooming stage will all take about 10-40 secs.

The water should just sit on top of the puck (in "suspended animation").

The Decent app recommends using a blue-tooth scale to keep track of how much dripping into the cup there is before the ramp stage.

They think that about 8 grams of total dripping, (within 2 grams), gives the best tasting results.

3. After the blooming stage is finished, ramp the pressure up (you don't want to reach 8-9 bar).

Just try to maintain flow at 2ml/sec. Between 2-4 bar should be sufficient.

I like to aim for a 1: 3 ratio.

Or go even longer.

Pull 1:4 or even 1:5

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I like to see this profile more as a flow profile rather than a pressure profile but of course pressure & flow are hard to separate.. It has 3 stages:

1. Pre-wet stage - 25sec - 4g/sec

2. Bloom stage - 30sec - zero flow

In this stage we stop the flow but try to maintain some (passive) pressure.

This is hard to achieve on most automatic machines (not the Decent, Gaggimate or lever machines)

since when you stop flow, you stop pressure (the OPV opens on most machines).

It's important to have some remaining passive pressure in the system to maintain

puck integrity.

3. Brew/percolation stage - ramp up to 2g/sec and maintain for 25 secs

This is a shot from my modified Rancilio Silvia (Gaggimate mod)

Flow is the priority

1. 4g/s for 7 secs

2. zero flow for 30 secs

3. 2g/s for the rest.

My aim was a 1:3 , 1:3.5 ratio.

18g in, +54g out.

I manually stopped the shot at 60secs when I reached 62g.

I need to grind finer. Dripping too much in stage 1.

and the pressure never rose above 1 bar in stage 3.

I don't have a TDS meter so can't give a scientific measure of the extraction levels, but it tasted strong. Quite pleasant, sweet, a bit of acidity. not bitter.

Gaggiuino also have a version of this which I'll explore later.

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Coffee index. Click here :

https://djjondent.blogspot.com/2024/03/coffee.html

The Slayer shot profile.

This is another famous espresso style which many baristas try to emulate on their coffee machines.

It was made famous by the "Slayer machine"

The Slayer is one of those holy grail machines. They are hand made in Seattle since 2007.

+ Video

This pic is of a single group version with a saturated group head.

What truly sets Slayer coffee machines apart from the rest are their patented mechanical needle valve.

In the video Slayer show how to vary the flow rate with the paddle which adjusts the valve.

The flow can be varied between

55g-60g/30sec for more developed coffees (dark roasts).

45g or 50g/30sec or medium roast coffees,

40g - 45g/30sec for light roast coffees.

This valve was created to control the flow rate

and gives you the ability to adjust the water flow during the pre-infusion stage.

The pic below is from the excellent Decent app.

https://decentespresso.com/downloads

What the graph above doesn't show is the flow.

A slayer shot puts water slowly onto the puck (2mls/sec) for typically 25 - 40 secs.

(Its very different to a Londinium shot).

You can try to emulate this with any machine which allows you to control flow.

Breville dual boiler users can do a Slayer mod.

The example below uses a modified Rancilio Silvia (Gaggimate).

Of course, the Gaggimate, Gagguino and Decent don't have mechanical needle valves.

My Rancilio-Gaggimate for example, manages flow by adjusting the vibratory pump's duty cycle through a solid state relay (SSR). It integrates a pressure transducer and a blue-tooth scale which can monitor flow.

But I do have a E-61 with a needle valve so this might be the closest I can get to a Slayer without buying a real one

https://slayerespresso.com/dialing-in-the-slayer-espresso/

In the above link, Slayer recommend this as a general starting recipe:

Use a standard basket with 18-20g size (dose should be within +/- 10% of the basket size)

Brew temperature: 93c

Pump Pressure: 9 bar

Needle valve flow rate: 50g/30sec

Ratio: (1:2) 19g in, 38g out

Pre brew time (pre-infusion) : 25 secs

Brew time: 25 secs

Total contact time: 50s

The Slayer profile I'm using at the moment is slightly different. It's called "Slayer Flow".

It has two phases:

1. Pump more = Flow

duration 30s

pressure=0

flow = 2g/s

valve = open

Ramp = instant

Temp = default

2. (pump mode = pressure)

duration 60s

pressure 9 bar

Temp = default (zero)

Valve = open

Ramp = instant

Temp = default

To summarize:

It uses very low initial pressure (zero) & flow (2g/s) during pre-infusion.

At the end of this time, the puck is fully saturated and the pressure will rise.

You only end the pre-infusion when you see the first drops of coffee at the bottom.

I programmed the first phase to last 30 secs, but I seem to get the first drops at 15 secs ... so I think I need to grind much finer (or use a slower flow).

I was using a DF64V at setting 15 @ 1300rpm. I could also increase the speed to increase the fines.

The nice thing about this is that it addresses solubility, esp for coffees like light roasts (where you need more contact time). The puck releases CO2 & gently expands in the basket. ... less chance of channeling. Which leads me to the question... should I use a puck screen or not? I don't know the answer.

Because prefusion takes so long, there will probably be a difference in water/coffee contact between the coffee at the top and the coffee at the bottom of the puck.

The coffee at the top might have been in contact for 30 secs, while the coffee at the bottom only 1 sec. ???

This gradient between the top and bottom might result in an uneven pre-infusion.

(The top might be over extracted, while the bottom is under extracted.)

But maybe with my current grind setting, this isn't such a problem. I'm getting the first drops at only 15secs with zero pressure.

Anyway, this pre-infusion is followed with a full pressure (9 bar) extraction.

Some baristas might choose to reduce the full extraction pressure slightly (e.g., 6-8 bar) to further enhance the effects of the pre-infusion.

This shot was 18g in, 48g out.

I was aiming for a 1:2.5 ratio but of course there are no firm rules for this. If it tastes good for you then you've succeed.

This is an earlier shot I did with the same beans but a coarser grind.

I manually stopped the shot at 48g but if I can prefect the grind this should be automatic.

In summary:

A Slayer shot on a standard espresso machine involves mimicking the Slayer machine's two-stage brewing process, which includes a low-pressure pre-infusion and a full-pressure extraction.

This technique aims to highlight different flavors and textures in the coffee by gently saturating the puck before full extraction.

While Slayer machines have a needle valve for precise flow control during pre-infusion, standard machines can achieve a similar effect using techniques like a slow fill or a low-pressure pre-infusion.

I also have a e-61 with a needle valve flow control which I will try in the future.

I'm not certain the difference between this vs the slayer valve.

Use a 2-bar pre-infusion (for 20-40 seconds) and then move to full pressure extraction for another 12-13 seconds.

The total shot time is long in some recipes, aiming for more than a minute.

Some baristas choose to reduce the full extraction pressure slightly (e.g., 6-8 bar) to further enhance the effects of the pre-infusion.

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Coffee index. Click here :

https://djjondent.blogspot.com/2024/03/coffee.html