Second pull on Breville Barista Pro takes much longer

Need help with equipment usage or want to share your latest discovery?
drflossy

#1: Post by drflossy »

Hey folks,

I'm fairly new to the espresso community, but recently picked up the Breville Barista Pro. When I make back to back double shots, the second shot tends to take a much longer in time. No change in grind setting or any setting for that matter. Volume wise, both pulls are about the same. The first shot typically takes 27-30 seconds and then second around 40-42 seconds. Any thoughts? Typically I follow this routine:

1) Turn on machine, pull two blind shots to warm up group head and portafilter, wait a few minutes
2) Weigh out around 17.5g of coffee directly into portafilter with single wall basket with a dosing funnel
3) Tap out any clumps (may need to start using a WDT)
4) Use a distributor to even out the bed
5) Use a hand tamper with fixed length for more consistent tamping
6) Press the standard double shot button on the Barista Pro

In between the second shot, I tap out the puck. Place the portafilter back onto the group head and run a blind shot. Clean off the portafilter and group head. Tap out as much retained water in the portafilter and dry the basket before grinding a second batch of coffee (following the same steps above).

The only thing I can think of that may be causing this is inconsistent distribution of the coffee and tamping. When I don't make back to back shots, I don't seem to run into this issue. It is only when I am making back to back shots, one right after the other, that I notice this.

Any thoughts?

Thanks!

jcmonty

#2: Post by jcmonty »

Welcome! I recently had similar issues to you with this machine. You may want to review this thread as the experienced members on this board definitely helped my journey (still a process TBH):

Breville Barista Pro - Inconsistent output with a standard process?

Top recommendations I would make for you is to :
1) WDT - definitely helped with consistency for myself. Homemade cork with 4-5 0.4mm acupuncture needles currently.
2) Pull manual shots. The volumetric function is hopelessly inconsistent.
3) Weigh you output to be able to really monitor what you are getting. Volume measurement is inconsistent.

Those two suggestions should help with consistency. I still get 3-5 seconds or so difference between shots with roughly the same weight output. I have. Niche grinder on the way, which should be a step up. The built-in can be limiting at times.

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drflossy (original poster)

#3: Post by drflossy (original poster) »

Hey Jon,

Thanks for the reply! I should have clarified about the output. I use a scale and weigh in grams for output as well.

I just came across that very thread you linked and it seems like WDT will help with consistency. I'll have to give it a try and report back. I'll also modify my process and try pulling manual shots. When doing so, are you going simply based on an in to out ratio or do you wait for change in color of the shot as it comes out of the portafilter?

Thanks again!

Edit: BTW, I was also considering a Niche Zero as I was thinking about this issue today...

jcmonty

#4: Post by jcmonty »

I am generally aiming for a ratio and adjust grind if needed due to obvious taste characteristics (not truly able to discern flavor notes) or shot time too far outside of a ~ 25-35s range. I do have a bottomless PF and take notice of color, but I am not skilled enough to solely base off color changes, especially since I tend to have a few different coffees I am trying at a given time.

Henry_k

#5: Post by Henry_k »

No flush before first extraction? Do a 5s flush before each extraction and check results.

klee11mtl

#6: Post by klee11mtl »

You don't explicitly state it but it sounds like your first shot might be after a long idle time? If you're like me and make multiple shots in the morning and then the machine sits idle for almost 24 hours it may be that the ground coffee retained in the machine has been sitting there exposed for that time. So your second (and subsequent) shot is the normal pull expected for your grind setting and the first one is a gusher due to the "not so fresh" grounds.

If this sounds like your situation, you can try purging some coffee before your first shot. For me, in addition to purging I try to leave my hopper empty overnight and fill in the morning with only what I expect to use.

drflossy (original poster)

#7: Post by drflossy (original poster) »

jcmonty wrote:I am generally aiming for a ratio and adjust grind if needed due to obvious taste characteristics (not truly able to discern flavor notes) or shot time too far outside of a ~ 25-35s range. I do have a bottomless PF and take notice of color, but I am not skilled enough to solely base off color changes, especially since I tend to have a few different coffees I am trying at a given time.
Thanks, I appreciate the help. I'm also fairly new and unable to discern any unique flavors but I do have the acidic/bitter flavors down pretty good so far!

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drflossy (original poster)

#8: Post by drflossy (original poster) »

Henry_k wrote:No flush before first extraction? Do a 5s flush before each extraction and check results.
I do a couple blind shots before the first extraction and then also between extractions to clean the portafilter and group head!

klee11mtl wrote:You don't explicitly state it but it sounds like your first shot might be after a long idle time? If you're like me and make multiple shots in the morning and then the machine sits idle for almost 24 hours it may be that the ground coffee retained in the machine has been sitting there exposed for that time. So your second (and subsequent) shot is the normal pull expected for your grind setting and the first one is a gusher due to the "not so fresh" grounds.

If this sounds like your situation, you can try purging some coffee before your first shot. For me, in addition to purging I try to leave my hopper empty overnight and fill in the morning with only what I expect to use.
That's an excellent point! I do leave beans between the hopper and I'm generally pulling shots before work, so almost exactly 24 hours between pulls. I'll move to single doses to see if that helps with consistency.

For reference, I pulled a double shot this morning before work which was a 30 second pull with about 17.5g of grind. About 14 hours later, I pulled two back to back double shots with a dose of 17.6 grams (they were within 0.1g of each other) and they both pulled at 29 and 32 seconds. I think you're onto something here!

I appreciate the help everyone!

Mack21

#9: Post by Mack21 »

+1 for purging the grinder before your first shot. As mentioned by others, it's otherwise likely that your first shot will be a mix of stale and fresh coffee with second shot being just the fresh grind (which you would expect to run slower)

jcmonty

#10: Post by jcmonty »

One thing I forgot that did that helped with any retention or stuck beans (I would always find a bean or two jammed between the hopper and grinder ) was to add some filler material around the rim of the burrs. I used a bit of shoelace which seems to work well. It fits in the small channel that you can see between the machine body and the removable burrs.