Breville Barista Pro – Second Shot Slower Than First

Update 3/13/2021: I emailed Breville with my question.  Long story short, they told me to send it in for servicing.  They paid for UPS to package and ship the machine.  A few days later I get an email that a new machine is being sent to me.  I called and tried to find out what they found wrong but they had no information.  Rather than open the replacement, I decided to take the opportunity to upgrade – I’ll sell the replacement and I bought a Breville Dual Boiler.  Unfortunately, I have no way to know if the new machine would have the same problem or if it really was something wrong with my old machine.

Original Post:

I’ve had my Breville Barista Pro since around October 2020.  Most days I make two shots in the evening with decaf beans – one for me and one for my wife.  For the decaf beans, I’m using a Mazzer Super Jolly grinder with SSP Silver Knight Burrs, with the Daniel Wong doserless mod.

I’ve noticed that when I make the two shots, the first shot runs quicker than the second shot.  I can compensate for the difference by adjusting the grind coarseness (grinding coarser on the second shot), but it does make dialing in a little more difficult.  I have looked around online and found other people with similar issues, usually with the more widely owned Breville Barista Express.

Here’s a summary of the theories as to why it happens and what I’ve found.  I will post the details of where I found which information with links.

1. Temperature of the portafilter (LIKELY but still testing).  At first I thought this wasn’t the case, as I always run a blind shot through the portafilter before my first extraction.  The hot water sits in the portafilter while I’m preparing my grinds for the first shot.  I have since tried running all sides of the portafilter under the hot water for a longer period of time and it seems to be helping.  I think a hot puck of ground coffee warms the portafilter more thoroughly than just the hot water running through.  In a home-barista thread I linked to below (the one for the Oracle 980XL), there are several interesting points.  The first response right away targeted the temperature.  The first page also had a discussion of similar issues from Silvia owners in the 1980’s.  Rather than make a shot of espresso and waste the first shot, some people would leave the grounds from their last shot in the portafilter until the next day.  They would then run a shot through the old grounds to warm up the portafilter better than just having the hot water without the grounds.  I haven’t tried this approach yet, but will update as I find good solutions.
2. Stale grounds in the first shot (DISPROVED).  Most discussions mention the possibility that the first shot will have some grounds that had been retained in the grinder from the previous time it was used.  Stale grounds will pull quicker.  I tested this theory by grinding two shots worth at the same time, and using the fresh second set of grounds for the first shot pulled, and then I used the possible “stale” set of grounds and used that for the second shot.  My first shot (fresh grounds) had a 6 second pre-infusion with pulled in 31 seconds, 17g in and 34g out.  The second shot (potentially some stale grounds) had a 6 second pre-infusion and pulled in 40 seconds, also 17g in and 34g out.  To me, this ruled out the stale grounds theory as the cause of the second shot pulling slower, at least for my situation.
3. Grounds clogging the portafilter (UNLIKELY).  The idea being that finer grounds from the first shot will get stuck in the holes in the portafilter, thus making the second shot flow slower.  Ways to prevent this include better rinsing/purging of the portafilter between shots.  Several people (myself included) question why this would be much different after the first shot, but somehow the stuck grounds would magically disappear after the last shot of a session and before the first shot of the next session.  Some theories are that as the grounds dry out they shrink and fall out.  I think this is pretty unlikely but suppose it is possible.
4. Moisture in the portafilter (UNLIKELY).  The idea being that extra moisture before you refill the portafilter slows the extraction.  I’m pretty good about drying the portafilter between uses, but it is possible some moisture under the basket drips through when I invert my portafilter to place it on my dosing cup.  Since I run a blind shot through the portafilter to warm it up before the first shot, there should be a similar amount of moisture present for the first shot as there would be for subsequent shots.
5. Defect in the machine.  At least one user had their machine replaced by Breville.  If doing a better job of preheating the portafilter doesn’t fix the problem, I will contact Breville for further advice.

Here are summaries of various discussions I have found on the topic.

Home Barista Posts:

Breville 870XL second extraction pressure

Posted 3/15/2017.  There are about 50 posts over a one year period, covering all possible issues.  The machine discussed the Breville Barista Express, 870XL.

Why is my first shot in the morning always poor compared to the second one with no changed settings?

Posted 3/27/2017. This discussion was with the Sage Oracle (Same as Breville Oracle 980XL).  This includes 32 posts.  This is not the exact same issue, but the discussion and the suggested solutions seem to match my experience and are the best / most accurate of the lot.

Reddit Posts:

Why does my Breville Barista Struggle to Pull a Second Shot?

Posted 5/19/2018.  This seems identical to the issue I have, but with the Breville Barista Express (instead of the Pro like I have).  There is no solution posted, but suggestions included the machine not being designed to pull back to back shots without letting the machine recover the temperature.  Also, retained grounds being used in the first shot, as stale grounds at the same coarseness would create less pressure and pull faster.  Last, some people said perhaps the basket is actually clogged and needs to be cleaned better.

Breville Barista Express consecutive shots

Posted 12/16/2018.  Suggestions were to dry the portafilter better, to flush the machine between shots with the portafilter in place, and question of retained grounds for the first shot.  Again, no feedback whether addressing any of these issues fixed the the problem.

Issues with making a second cup of coffee with the Breville Barista Express

Posted 4/29/2018.  Barista Express. Second shot with identical preparation has higher pressure, slower extraction, and over extracted taste.  They also noted the amount of espresso made is about 20% less.  My guess is they hit the OPV (over pressure valve) maximum pressure, which causes some of the water to go into the waste bin rather than the cup.  I don’t use the default settings, so I just get a much slower extraction, and maybe I’m hitting the OPV max pressure.  Interestingly, he/she contacted Breville and was told the machine was malfunctioning.  They sent him/her a replacement which did not have the same issue.  This makes me wonder if many machines have this same issue, or if this person’s was far worse than what other people are reporting.  Other people in the thread reported the same issue.

HELP! Why does my second shot tend to choke!

Posted 6/29/2020.  This person is using the Breville Infuser, which is similar to the Barista Express, but without the built in grinder.  This person said the problem was solved by letting the machine warm up much longer and this led to a better extraction as well as better taste.  My impression has been that with the thermojet in the Barrista Pro, there really isn’t anything warming up beyond the several seconds after turning the machine on.  Perhaps I’m wrong and should look into this further.  Maybe the thermocoil in the Express and Infuser warms up differently.

Help with Second Shot on Breville Barista Express

Posted 9/9/2019.  Owner of Breville Barista Express, the original poster never says how their shot times were but they report that the pressure is lower on the second shot compared to the first. In the short time that I used a Breville Barista Express, I found that low pressures occurred when the grind was too coarse, and the shot would thus run fast.  This would seem to be the OPPOSITE problem to what I have.  The Barista Pro does not have a pressure gauge, but typically, the finer the grinds, the higher the pressure will be, up until you hit the maximum pressure allowed by the machine (set by an over pressure valve). A few people in the thread did say they find the second shot runs faster for them, so they grind FINER for the second shot to compensate, also the opposite of what I am finding.  Nonetheless, to try to troubleshoot the issues, I think the potential issues and solutions would be the same.  One person measured the in cup temperature and found the first shot on the Barista Express was 140 degrees and the second shot was 125 degrees.  This makes me curious as to what the in cup temperature is for me.  I will likely check it once I get a decent thermometer.

Breville Barista Express – 2nd/3rd shot help

Posted 2/2/2021.  They reported normal use of the Breville Barista Express for the first two months and then suddenly the second shot basically choked the machine.  Happened again the next day after fully cleaning the machine.  People again suggested stale grounds, which I have been able to rule out in my situation.  Given the sudden change in functioning, this sounds more like some type of malfunction.  I’ll try to remember to follow this thread to see if they find another solution.