Trouble dialing in 2:1 brew ratio

Beginner and pro baristas share tips and tricks.

Postby cremaftw8 » Sep 29, 2018, 1:28 am

Hi guys,

I recently purchased a Breville dual boiler bes920 with the smart grinder pro bcg820. But I am having issues with the ratio of espresso shots. I set my burr grinder master adjustment at "6" then proceeded to make minor grind size adjustments, but the volume of shot I got at the finest setting was in the range of 70ml for 17g of beans. I then changed my burr grinder master adjustment to "5" and repeated the process but it wasn't doing any better.

I have ensured to toss out some of the coffee grinds every time I changed the grind size.

The shots were set at a dose of 17g, 90°C and 30 seconds shot time (including pre-infusion time).

I have been trying to get a 2:1 ratio of volume of shot to dose but have failed miserably.

My coffee puck would occasionally get stuck to the shower screen, but it is really random even for the same dose. (How can I prevent this?)

The potential issues I identified were:
1) Grind dose (17g too much?)
2) Tamping inconsistency (not hard enough?)
3) Temperature (does this affect shot volume?)

Would appreciate if you could give me some pointers to improve my shots.

Many thanks,


Postby HH » Sep 29, 2018, 1:36 am

Hi Jim,
Congratulations on the purchase! I had a very similar issue to you when starting out with the BDB. I have found that the basket really likes being dosed between 18-20g. When I dose less than this the shots can run through very quickly. Try dosing 20g and seeing if that helps.
I always tamp to full compression for consistency, and usually have temperature around 92-94'C. Higher temperatures tend to increase extraction, but I haven't noticed a massive impact on flow rate.


Postby cremaftw8 » Sep 29, 2018, 4:20 am

Hi Henry,

Thanks for the response. I will try increasing my dosage to see if it makes any difference.

Just as a general rule, does an increase of coffee dose affect the amount of espresso delivered?

Many thanks,


Postby HH » Sep 29, 2018, 7:25 am

Hey Jim,
No problem - always happy to help. As a general rule, dose of coffee grounds in and dose of espresso out are certainly not set in stone. Different baristas will use different ratios of coffee grounds to espresso depending on both the drink they are making and the individual beans.

A common starting point is 18-20g of coffee grounds in, to get 36-40g of espresso out the other end in around 30 seconds. It varies, but I believe most would recommend that 30 seconds should start when the first drop of espresso hits the cup. For us using a BDB, that means taking note of how many seconds are on the shot timer when that first drop hits - and for me that's typically around 7-8 seconds - and adding that on to the shot time.

Hence I usually end up, when pouring a normale espresso (one with a 1:2 ratio as above), getting 36g of espresso from 18g coffee in around 38 seconds.

An excellent reference can be found below, which I found really useful.

Espresso 101: How to Adjust Dose and Grind Setting by Taste

Let me know how the shots turn out with 18-20g in the basket. If you get stuck, post a couple of pictures or better yet a video and I'm sure we can give you some pointers.
Good luck!

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Postby sweaner » Sep 29, 2018, 9:08 am

Assuming that you are using fresh coffee, grind finer until you hit your goal!
LMWDP #248


Postby Deebo » Sep 29, 2018, 9:28 am

Your ratio should be based off of weight, not volume.

if you're going for 2:1, with a 17g dose, the output should weigh 34g.

If you're using a 20 g dose, the output should weigh 40 g, etc.

Forget about volume, extract by weight.
Think it, but don't overthink it...


Postby cremaftw8 » Sep 30, 2018, 10:22 pm

Hi All,

Thanks very much for the response.

I have tried dosing 20g of beans and it gave me 50g of espresso - which is a much better improvement compared to before.

My grind adjustment was already at one of the finer selection when I made that 20g/50g shot. Do you guys reckon using 21g would be a good idea or if I should change make even finer adjustments? I am concerned 21g may overfill the portafilter (is this true according to your experience)

P.s. Sorry for the late reply, I have limited amount of time everyday to test the machine, hoping to nail piccolo latte technique by the end of the month :D

Many thanks,


Postby HH » Sep 30, 2018, 11:39 pm

Hey jim - sounds like you're on the right track! I'd adjust finer now until you hit the 1:2 ratio, keeping the dose the same.


Postby Ldfoverdrive » Oct 01, 2018, 11:38 pm


You should be looking at 40 grams of espresso with 20 grams of coffee. 1:2 ratio if you have issues with the ratios, I suggest the free Brew Ratio app. It's been very helpful for espresso and method brew for me.



Postby Bret » Oct 02, 2018, 12:13 am

Are you using the auto buttons or the manual? You can program the single/double shot buttons to change the timing (or the volume, but stay away from that feature as it doesn't work well). But the problem with the auto is that it will run the same duration each time, and as the coffee ages or the grind changes, or the distribution is different, well, the output will not be consistent.

In manual, you control when the shot stops. Then you taste it. Then you change the time/grind/dose as may be needed. But you control the shot for the same output (or for less if it seems like the shot runs too long based on the taste). My standard dose is 20g and I seldom go as high as 40g out unless I get distracted. Depending on the coffee I use, I tend to stop the shot at 25-30g or 32-36g. That is not a rule, that's just what works for me and my set up.

I used the SGP with my BDB for years until I got a Monolith this year. The grind setting around 6 seems about right if the burrs are broken in. When mine was brand new, I was in the 8-10 range but over about 4-6 months it settled in the 5-6 range for me depending on the roast. So if you are getting close at 6, stay in that vicinity.

Search "salami shot" here on the site, try that out (can swipe a spoon thru the pull repeatedly if you don't want to fuss with lots of cups) and that can also help you see how the shot changes over the duration of the pull, and if you are getting flavors you don't want added in by running too much of a pull.