Gaggia Classic blooming espresso shot

[TigerStripes]

Made a quick video this morning to share how I make high EY shots with medium/light roast Kenyan beans.

I also used a filter paper on the bottom of this shot, which ups the extraction even more, but it does decrease the beauty of the bottomless portafilter extraction.

My Gaggia has several mods, but all you need for the blooming shot is the dimmer mod. I suppose it also requires a grinder that is consistent at a very fine grind.

[GDM528]

What was the final brew ratio?

Have you tried higher PID settings?

If you've got filter paper disks sized for your portafilter, you could try placing a second filter roughly midway through the puck. I think it stops top-to-bottom channels from forming that reduce the EY. I can maintain constant pressure that way - although I admit it's a hassle to implement, so I only do it when I need/want to pull an optimum shot.

[TigerStripes (original poster)]

Brew was 19g in basket, 40g coffee out.

My brew temp is 201f here. I've measured the water temp with a diy scace thermocouple. I find that if I go higher than that I start to get harsh bitter flavors.

[SutterMill]

I was distracted by the oil lamp chimney on the Sette. Is that a tight fit?

[TigerStripes (original poster)]

Haha, yeah that is my DIY hopper until I can get a few replacement parts from baratza. It's actually an old plastic water bottle I hacked apart

[GDM528]

So this is very close to my workflow - only now I know what to call it

I too use a dimmer to modulate the pump, but I took a couple of intermediate steps:

1) Use the steam wand valve to bypass the pressure
2) Split the single brew switch into two independent switches for the pump and 3-way respectively.

The dimmer switch gives the most flexibility to control the flow rate post-soak.

[TigerStripes (original poster)]

If you are using a steamwand to bypass the pressure, does that mean you are recycling hot water into the reservoir? I would assume your boiler temp would drop pretty quick if so, but maybe I'm misunderstanding your approach. I'd love to see a picture of your setup - I don't think I've heard about a similar approach yet.

[GDM528]

I'm not a fan of using the steam wand to bleed off pressure, so that was a short-lived technique for me. As you suggest it lets in cooler water, especially if you're running the PID low. Water enters the boiler at the bottom and exits at the top, so for small amounts of water dispensed the temperature drop is manageable.

I second your motion for the dimmer-mod Gaggia - transformed the machine IMHO. I used a teensy tabletop lamp dimmer so I could integrate it into the Gaggia: Another Gaggia Classic dimmer mod

Lately I've been trying a variation of the blooming technique:
1) Apply very slow pressure/flow ramp until puck is fully wetted, typically 10-15 seconds.
2) Stop ramping dimmer but leave as-is. Watch the thick, syrupy espresso slowly drip-drip into cup, another 15-20 seconds for less than 10g in cup.
3) When I can't stand to wait any longer, slowly ramp up the pressure until I approach 2:1 brew ratio.
4) Based on observed puck flow resistance, possibly adjust pressure down to keep shot from running away as it crosses the finish line. If I prep the puck well, this won't happen.
5) Stop based on the color of the extraction, usually lands a bit over 2:1

Not really paying attention to how long it take, but I estimate a bit over one minute from wetted puck. So, I'm close to the water-contact time of a blooming shot, but water's never static.

[TigerStripes (original poster)]

Sounds more like a slayer shot than a blooming espresso, but agree that's another fantastic way to pull shots.