# Units confusion



## johnlevon (Mar 13, 2015)

I'm rather confused about units mentioned as ideal shot times. For example, here:

http://www.home-barista.com/espresso-guide-good-extractions.html

says "looking for a two ounce double espresso in 27 seconds"

whereas here says:

http://coffeeforums.co.uk/showthread.php?22879-Beginners-Reading-Weighing-Espresso-Brew-Ratios

"I dosed 18g of coffee and made 36g of espresso in 27 seconds"

But 2 oz is 56g. 2 fluid oz is 56ml, and surely espresso is mostly water, so that's near 56g too.

So do I want ~30g or ~60g in my final coffee? Which of these is actually a double espresso?

My last shot was 17g dose, 35g coffee in 20 seconds. I think I want slightly bigger dose, or a slightly tighter grind?


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## Mrboots2u (May 10, 2013)

A double espresso is what you make with a double basket.....

IF ( no one of forcing you , it makes life easier to talk to other people though ) you are going to work to brew ratios then weigh in and weigh out - volume is irrelevant in this equation ( as the article in here suggests )

in the end you want, in the cup is what tastes good , using weight to measure this , is a way of measuring what you are doing and repeating it ...

I wouldn;t get hung up on what a double or ristretto IS....just what you like the taste off and being able to repeat it

here is some further reading

http://baristahustle.com/espresso-recipes-measuring-yield/


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## NJD1977 (Dec 16, 2014)

Espresso is nowhere near the same density as water, it is much lighter because of all the aerated crema. 56ml by volume of espresso will weigh much less than 56g.

Ignore volume and go by weight using some small digital scales.


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## Eyedee (Sep 13, 2010)

This forum seems to function best on grammes, ignore volume and weigh input and output in grammes.

Members will immediately understand any posting or questions using this measurement.

17g in, 35g out in 20 seconds, a minor adjustment on the grinder would extend the time but taste is the ultimate guide.

Sorry for the repetition, I must have been typing while others were posting

Ian


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## Dallah (Jan 31, 2015)

The 1ml equals 1g is only valid for water. 1ml of espresso would have greater mass (technically different than weight) than 1ml of water due to the very fine solids held in suspension and the emulsified oils.

As Boots says weigh and weigh out for the best predictability and consistency of result.


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## MWJB (Feb 28, 2012)

A double espresso is an espresso of pretty much any volume/weight, made from a dose of 12-22g, or more if you can stuff it in your basket. Though a 21g basket, or larger may also be described as a "triple basket".

27 seconds - there is nothing magic about 27 seconds...don't beat yourself up trying to nail a time to the second. Record the time that your good tasting shots take, if subsequent shots take half/twice the time for the same brew ratio (shot weight/dose weight in grams) be suspicious, but don't be concerned about a few sec +/-.

Volume is not a consistent way to measure your output as crema makes it difficult to see how much of the volume is liquid or foam & this can change for the same bean as it ages anyway.

Use weight, some jewellery scales that read to 0.1g are useful here. Aim for a brew ratio, stick to that ratio, adjust grind only until you get the desired flavour balance, then assess if too weak/strong. If too weak, use a shorter brew ratio & adjust grind finer to restore flavour balance. If too strong, use a longer brew ratio & grind coarser to restore flavour balance. Personally, I'd start out between 2.5:1 (42.5g from your 17g dose) or 3:1.

What size is your basket? Overdosing by a large amount will affect its performance. If you are happy with 35g from 17g then grind finer to adjust the taste, using the same dose & output.

EDIT: Note to self to keep posts shorter so I don't look like a ninny, repeating what everyone else said...using half the words I did!


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## Dallah (Jan 31, 2015)

For clarity, when discussing volume I do not include crema.


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## MWJB (Feb 28, 2012)

ridland said:


> For clarity, when discussing volume I do not include crema.


But the Italians do.

How does that work in a ceramic cup?


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## johnlevon (Mar 13, 2015)

Thanks everyone, this helps. I should stick to weighing (I do have 0.1g scales I use), ignore any volume stuff. I know the numbers are just a guide but it's still useful to know typical values as there's so many variables.

Confused by the "stick to a ratio" thing. Won't the grind directly change that ratio? I.e. if I go looser, then I'll get more liquid out of the same ground coffee. So how could I keep the ratio the same while modifying the grind?

Finally, I rarely seem to get much crema. Is this just a matter of the beans? They're not old but not fresh fresh either (roasted last month I believe).

What controls that?


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## Jon (Dec 3, 2010)

johnlevon said:


> Confused by the "stick to a ratio" thing. Won't the grind directly change that ratio? I.e. if I go looser, then I'll get more liquid out of the same ground coffee. So how could I keep the ratio the same while modifying the grind?


You're looking to maintain the ratio *by *adjusting the grind.

Hope that helps.


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## Mrboots2u (May 10, 2013)

You can change the grind and stick to the desired ratio

the ratio will take different times to extract and as a result , taste different ....

So 18g>36g in 25 seconds

tighten grind

becomes 18> 36 g in 35 seconds

The latter may have different mouthfeel and be extracted to a different level ...you may prefer one more than the other ....

You change the grind ( and therefore time ) to reach a desired balance of taste within the brew ratio that you are working too .....


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## MWJB (Feb 28, 2012)

Maintain the ratio by killing the shot at the desired weight consistently. Taste it, change the grind & pull another shot...better or worse?

If you change grind & get a different weight of beverage in the cup, then you aren't brewing to that ratio any more...you have changed grind & ratio. By sticking to a ratio (+/-1g output) you are reducing the variables, so grind is driving the changes (assuming consistent prep).


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## risky (May 11, 2015)

Great info in this thread for newcomers, well explained, however I'd like to pick up on the two opposing views offered:



NJD1977 said:


> Espresso is nowhere near the same density as water, it is much lighter because of all the aerated crema. 56ml by volume of espresso will weigh much less than 56g.





ridland said:


> The 1ml equals 1g is only valid for water. 1ml of espresso would have greater mass (technically different than weight) than 1ml of water due to the very fine solids held in suspension and the emulsified oils.


Personally I would think that espresso will weigh more than the same volume of water (ridland school of thought). Does anyone else care to comment? Is this coming back to the whole 'do you include the crema in the measurement' argument?


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## MWJB (Feb 28, 2012)

We're using the measurement to kill the shot, so we're concerned with it's state at that moment in time...a shot with crema weighs less than 1g/ml.

If you remove crema, or let it dissipate, then the weight of the brewed coffee is more than 1g/ml. By this time, of course, you killed the shot some time ago and the crema-less measurement is pointless with regards to pulling the shot & judging when to kill it.


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