This is collection of information and learning pulled into single post that I digested through lot of reading on this site and then tested it and put into practice every single day. I pulled and tasted over 3,000 shots this year most of them using this technique or variation of it. I take no credit for it since credit goes to all smart people that obsessed over espresso on this site long before me.
I believe that this method is very useful for beginners and others that would like to improve consistency of their espresso making. I know that doing it this way provided huge consistency improvement for me so I am sure someone else will benefit as well.
Basically this is what I wish I read and tried when I was just starting so here it is.
What is this Digital in title of the post? I mean that as a hint to being precise and measuring what you are making instead of guessing. You can't control what you don't measure
so there you go...
This method, process if you will, involves measuring dose, the amount of coffee you use to make espresso, and measuring the resulting beverage weight. Why do it this way?
Traditionally people eyeball dose into basket by filling the basket to the top and level. That result in warring dose and your espresso will be moving target. Also different blends work best at different doses and this method does not even get you close to specific dose.
The amount of espresso made is traditionally defined in fluid ounces, so it is said that double espresso is 2 oz. This again is not precise enough since some coffees froth a lot and you get lot of crema which obscures the true shot volume. Additionally if you use 20 grams of coffee to make 2 oz of espresso, it is completely different taste profile than when you use 14 grams to make 2 oz so shooting for that 2 oz is imprecise.
There is also blonding, a term you must be familiar with by reading here. It is said to cut extraction when you see espresso stream go blond. I spent lot of time trying to learn how blonding exactly looks like, but it's like looking for Loch Ness. Using this method you can completely forget about that. If you have good distribution of coffee in coffee basket and simply even tamp you are good to go.
For this method you will be using 0.1 gram scale
to precisely weigh dose of coffee
and then weigh espresso
you extract. The ratio between dose and espresso weight then gives you brew ratio and better idea about the shot you made. You simply divide your dose weight with your espresso weight and presto! Andy Schecter proposed this back in 2006 as better way of communicating parameters between barista. Here is his post: Brewing ratios for espresso beverages
I think people should be using this all the time. It simply makes sense to know how much coffee you put in and how much you get out so you can repeat and most importantly tune up your espresso experience.
So how do you do it? Preferably, if your grinder allows single dosing, like Baratza Vario, Compak K10, Versalab M3 and others, you weigh the beans you want to use on 0.1 gram scale and grind them and hopefully you get out what you put in. You can experiment and see how much coffee your grinder retains. If you grinder cannot single dose then tare the basket and grind into it. Start with 14 grams for sake of experimentation.
Second step is to distribute and tamp. I will not go into this, but this is also important. I recommend using bottomless portafilter to be aware of channeling and uneven distribution. My experience is that good grinder helps a lot.
Then you lock-in your portafilter to pull the shot. You put your 0.1 gram scale under portafilter and your espresso cup on the scale. Don't forget to tare the scale to zero so you weigh only the espresso that is extracted.
You start the extraction on your machine and watch the scale. I find that for lot of coffees, I like about 70%-90% brew ratio. If you are shooting for 70% brew ratio that means that for 14 grams of coffee you extract 20 grams of espresso by weight in 25 seconds from the moment first drop of espresso hits the cup.
If you are over or under you adjust your grinder to grind finer or coarser until you can hit these numbers.
Final note, please don't get stuck on exact brew ratio or even exact 25 seconds of time. Rather use the measurement of input and output to find what you like the best. Once you have your espresso to your taste you might not even weigh your output. I use doses from 14-20 grams depending on coffee and my espresso weighs from 16-35 grams... I find that just 1-2 grams of espresso beverage weight makes difference you can taste.
This is just a tool so use it as such but don't get hang up with particular number rather explore and see what you like. Try using 16 gram dose and make 16 gram of espresso with it. Then make 30 gram espresso with same dose and see how you like that... I see this as speedometer on a car. Instead of guessing how fast you are going you look down and know exactly.
Here is Andy's brew ratio table that provides nice guidance:
But professional baristas don't do it this way you might say. True, but they also make hundreds of shots every single day. The muscle memory and visual memory for volume dosing is very developed so they don't have to and don't have time to do this in busy café. But you can bet that good ones know exact dose they are using and how much espresso they make with it. It's just that they work that out ahead of time for blend they are making and then use their muscle and visual memory to repeat it hundreds of times a day.
So this is all. I would love to read your comments on this and thoughts on what can be written clearer and better to explain this method, how we can improve it and most importantly I would love to hear your experiences.
Here is a video I created that shows my routine and weighing of input/output:
I used 18 grams of coffee to brew 30 grams of espresso by weight.