# Levels of caffeination



## mbenney (Apr 18, 2020)

Hello,

I've been working on my espresso making since the beginning of lockdown.

Set up - Rancilio Silvia 2020 (pressure at factory setting), Comandante nitro with red clix axle, Acaia lunar for weighing and timing.

Beans - Square mile seasonal espresso.

My PID is on the way, but I've been using the simpler flush some water and wait till 25 secs after the boiler light goes out method of temp surfing.

I've been doing pretty consistent 16g in, 32g out shots in 25-30 secs. They taste good, I've been really happy with them.

My problem is that my girlfriend is on occasion saying that the coffee I've been making has way too much caffeine and is giving her heart palpatations - even with a single shot.

But she's totally fine with double shot macchiatos from London coffee shops such as Grind.

They feel fine to me, even having a triple with the left over shot.

But as a beginner, can anyone tell me is there anything in my method or setup that could be making my shots more caffeinated than what you get in a coffee shop?

The variables I'm most unsure of at the moment are temperature and pressure.

Feels like a crazy question, but maybe there's an explanation.

Thanks very much


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## Rob1 (Apr 9, 2015)

Unlikely to have vastly more caffeine. Especially if she has doubles just fine. Maybe her intake from other sources has gone up? Or maybe she just doesn't like it...


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## TomHughes (Dec 16, 2019)

No, if anything based on your dose and the coffee you are using (pure arabica) it might be the other way. 
Caffeine is extremely soluble in water, so you will extract pretty much all of it from a certain amount of coffee in an espresso.

It is a myth that coffee of different roasting levels has different caffeine levels, this was largely based on the volume (not weight) in that a larger volume of dark roasted beans will weigh less so have less caffeine in. A lighter roast which is denser has higher caffeine, per volume. but if you are using weight it's the same.

The cafes, probably not decent ones, might be using robusta blends, which would be HIGHER caffeine.

The other thing to bear in mind is there is a significant placebo effect with coffee and caffeine. I'll try to dig out a paper later, but decaf has been known to elicit the 'feelings' of caffeination because of the brains association between coffee and effects of caffeine.

This can be increased in a darker roast (more powerful bitter flavours) and less milk/sugar.


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