Hi There,

Fairly new to espresso at home (6 months) and to make things repeatable, I've been using the same beans and logging...

• Grind
• Dose in
• Extraction out
• Brew temp range
• Amount of beans in the hopper
• Ambient temperature and humidity

Have learnt a lot since I logging BTW. I purchased a used commercial grinder a month ago (Macap MXD) and everything was instantly repeatable up until this morning when extraction times suddenly got longer by 20-30s.

The grind and everything is the same (same basket etc), even ambient temps and humidity logged have been fairly constant (17-20º, 50%-56% humidity). The longer times recorded this morning were at 17-18º and 51%-52% humidity for example. I pulled three shots just to be sure.

Questions:
Is it possible that changes in roasting could cause this or maybe the number of days since roasting?
Is there anything else I should look for?

A 20sec change in extraction time is a bit weird right? Any pointers in the right direction would be much appreciated.

Cheers

Ben

Each day I adjust my grind slightly finer to compensate for the aging of the bean.

BenS wrote: Is it possible that changes in roasting could cause this or maybe the number of days since roasting?

Yes, all else equal, extraction times can change with age. You can see it happen in this experiment, for example: http://www.youtube.com/watch?v=6TMkDe1XtIM

Since coffee beans are an agricultural product whose availability can be affected by all sorts of factors, I wonder if your roaster could have also changed the beans they are using or some component of the blend (if it is a blend). That could also impact your shot times.

BenS wrote: Is there anything else I should look for?

If you are able to rule out a technique issue because you're logging/repeating all of your process and you have seen very consistent results before this AND if you ultimately think is not a about the coffee itself, then you could check if anything is affecting the brewing pressure in your machine.

Thanks guys, will pay more attention to bean age and log it! Cheers

If everything is the same then you should check your machine. In mine after a few years suddenly I couldn't get any steam from it. It turned out is was scale. After discaling everything was fine

Weigh your coffee again after it's gone through the grinder to ensure the dose is still the same, accounting for any addition of water through RDT.

SandraF wrote:Each day I adjust my grind slightly finer to compensate for the aging of the bean.

I need to do the same. Not necessarily every day, but as the beans age the grind needs to get a little finer.

To the main question, a 20 second difference is a lot. I get 5 second swings sometimes but not 20 second swings.

Changes in roast definitely, even if from the same roaster and same name of roast. Did you just switch bags when this happened?

Time from roast is very important, but usually as the beans age it runs faster, not slower.