Sometimes I come across really interesting comments in my videos and I can't help but respond. More recently, this is what I came across:
hey Mark :) i have the Expobar Brewtus (thanks to your recommendation :) ), and i was wondering, what are the best settings for a perfect espresso shot? (brew temp, pressure etc.) Thanks! :) love your channel
There is no group of settings which will make the perfect shot. Making the best possible shot depends on a bunch of variables coming together to make an espresso you like! That said, I can give you some basic guidelines.
The range for espresso brewing is 195 - 205°F (that's 90.5 - 96°C). A general temperature guide is to tend cooler for darker roast and hotter for lighter roasts. My personal range is 198 - 203°F with the majority of the extractions at 199 - 201°F.
9 bar is the normal max, but anywhere between 8-10 bar pressure is fine. Pressure while brewing is determined by grind size. If the grind is too coarse, the pressure will be low. If the grind is too fine, you could max out at 9-10 bar and little to no espresso will come out. We set machines to provide about 9 bar max. With brew pressure, more is not better. Going beyond 10 bar will usually result in over-extraction of the coffee.
Grind size is the most critical variable! Very small changes in grind size can have a big impact on extractions. If you have not watched it, please check out my video on dialing-in grind size.
I always suggest people start with making doubles. Singles are tricky and very few people do them. In traditional Italian style, doubles used 14g of coffee, but now very few high-end cafes or home users go with 14g. The average barista, according to an SCA survey, is using 19g for double shots now. I'm usually between 17-19 grams. Regardless of what dose you decide to use, it's important to be consistent with that weight as you dial-in the grind size.
Ground coffee should be distributed evenly into the filter basket without clumps. The coffee should be compressed (tamped) evenly. Don't worry about the old recommendation of 30 pounds of tamping force. Since that has become a thing, most have gone to using a slightly finer grind which does not, in my opinion, require excessive force to create a good coffee puck. Personally, I no longer use tampers. Levelers take care of distribution and compressing the coffee. They are more consistent. You can see how I use my leveler in this video.
Timing shots is the most basic way of knowing you are in the ballpark of a reasonable extraction. Beyond timing, you can use brew ratios for knowing when to cut a shot as well as taste and visual cues like blonding. For timing you want 20-30 seconds from first drip to a volume of ~2oz/60ml in your cup. Volume can be tricky to judge if your coffee is making a lot of crema! It could settle out from 70 ml down to 50 ml. Don't get to hung up on timing - it's basic and I've had delicious shots that went 35+ seconds. Some examples of different timings are that Expobar E61 groups have an extra pre-infusion chamber behind the shower screen so they take a few seconds longer to get to full brew pressure, and vibration pump machines are slower than rotaries.
I hope this answer helped you with some of your own questions! Check out our YouTube channel and leave a question or a comment on one of our videos and you'll likely hear back from me too!