Ratios and Math

[bclayton]

Hi All, new to espresso and enjoying the journey so far. A lot to learn and I'm deep in the rabbit hole. One thing I am very confused on is ratios and weighing coffee grounds in vs espresso out. I see tons of info detailing ratios of 1:2, 1:3, 1:4, etc. for ristretto, lungos, and the whole nine. Many of these state preferred weights something along the lines of 18 grams of coffee in to 36 grams of espresso out, which would be approximately a double shot. My question is....how does 36 grams amount to a double shot when the density of water is 1g/mL, ie 36g=36mL=1.2 liquid oz?

Another example is shown here from Clive Coffee for 18-20g of grind to make 30g of coffee (or 1.5oz as stated in the video). How does 30 grams of liquid make 1.5oz when that density works out to 20g/oz...IE less dense than water?? I'm confused, please help

 

[bclayton]

 

[Musicphan]

Hey there... i think you are overthinking a bit... I see a lot of times weight/volume are interchanged for ease of use/comparison vs. actual equivalence (if that makes sense). Using ratios is just a good way to really dial in your espresso... when using weight-based ratios it's easy to adjust and dial in your taste preferences. Hollar if you have other questions!

 

[bclayton]

Hey there... i think you are overthinking a bit... I see a lot of times weight/volume are interchanged for ease of use/comparison vs. actual equivalence (if that makes sense). Using ratios is just a good way to really dial in your espresso... when using weight-based ratios it's easy to adjust and dial in your taste preferences. Hollar if you have other questions!

My engineering background has clearly reared it's head. That said, how is the ratio actually applicable when grams of water out does not actually equal the volume intended? Especially considering folks say +/- 1 gram can make a difference in taste. Is this "misinformation" really that well publicized?

 

[Musicphan]

LOL... my father is an engineer and I have that tendency as well! I purely go off weight - for my espresso I use 18 grams by weight and have a small espresso scale that I measure the weight of the output. 28.34g of water is equal to an ounce so I find that a 2:1 ratio results in a little less than 2 ounces. I actually tend to pull my shots a little long. Regarding the -/+ gram... I kinda call BS to a certain degree on that. There may be differences in taste but there are so many variables I find it hard to pinpoint an exact reason (which is why I call BS a bit).

 

[Goast2]

To make espresso, you need to take 7-8 grams of finely ground coffee and pour it into the holder. Sometimes I put more, sometimes less, and I count the ratios here. You can tamp the coffee to give it a stronger taste. Then start the machine, and after 30 seconds the coffee will be ready. Coffee in the holder filter, everything is ready for espresso 6. Do not let the coffee boil in the Turk. Cold water is always poured into the Turk. It is advisable to use a small Turk to prepare one or two servings.

 

[xisula]

LOL... my father is an engineer and I have that tendency as well! I purely go off weight - for my espresso I use 18 grams by weight and have a small espresso scale that I measure the weight of the output. 28.34g of water is equal to an ounce so I find that a 2:1 ratio results in a little less than 2 ounces. I actually tend to pull my shots a little long. Regarding the -/+ gram... I kinda call BS to a certain degree on that. There may be differences in taste but there are so many variables I find it hard to pinpoint an exact reason (which is why I call BS a bit).

Thanks for the nice informative reply.

 

[JeffD]

I never thought to make coffee with a calculator.

Really? I do it all the time. It makes a difference.

For example, I did a measurement of how consistent my idea of a teaspoon is. And let me tell you not only was I off, but I was inconsistently off. Eye opener. Now I have a cheap little digital kitchen scale and a weigh everything. Yea I feel like a nerd, but darn my coffee is good.