Breville Dual Boiler Learning Curve?

Need help with equipment usage or want to share your latest discovery?

#1: Post by tennisman03110 »

Hello All HB:

I powered up my brand new Breville Dual Boiler today. My Duo Temp has been assigned to the closet (for now....).

I made some water with distilled water/baking soda. Cleaned up and organized my area. Bought a bottomless portafilter on Ebay and had everything ready to go.

Using my Sette 270 (grind setting the same as my last shot with the Duo Temp) and some Onyx Southern Weather (roasted 7/10), I dosed and tamped 18g into the double basket with the bottomless portafilter. Bravely, I pressed the manual start.....and what a disaster. Thanks for all the buying advice :wink:

Within about 3 seconds, still in pre-infusion, the coffee came trickling/spurting out the sides, down the handle, etc. None out the bottom. I bailed 5 seconds in, it happened so fast I never saw the pressure gauge. Attempt two, I upped the grind size from B to G (micro) and went with the standard portafilter. I bravely pressed on....and it poured so fast, pressure was about 5 bar max. 40g out in 15 seconds.

Attempts 3-5 I reduced grind size, all came out fast. By attempt 6, I was 100% AT the grind size I started with. Still very fast, not enough pressure (did hit 9 bar briefly), etc. While things were improving, I only have limited coffee left, and gave up for the day.

Some questions that I haven't found a definitive answer to:

1. Is there a known grind size difference between 53mm and 58mm portafilters? How about for a standard vs. bottomless?
2. My portafilter barely turns to the middle in the machine. I assume don't force it, just a new gasket? The bottomless turns even less than the standard, maybe to 8'oclock (6 being the middle).
3. On my last attempt, still poured too fast, the puck didn't look "right" at the end. The surface wasn't flat, and there were some grinds all the way up on the silver part, not even the basket.

I've learned enough from the Duo Temp to make good consistent shots. I changed almost nothing myself. Obviously the machine change is substantial. Anyone with input, it is appreciated. I went through one learning curve, can't say I expected such a disappointing start with the BDB.

Supporter ♡

#2: Post by HotLava »

The gasket will be tight for a few weeks, so you may have to man handle the portafilter to get it to oclock but it will go. That may be part of the problem. What is the puck prep routine? Make sure your distribution is good and tamp down enough. As long as the grind is right you should be fine. Unless the coffee is old.


#3: Post by tennisman03110 »

I read you should not force the handle to turn...but maybe I should?

I grind into a cup, the pour into portafilter with funnel. Shake it a bit, then use leveler, then tamp. It's exact same I've used for 5 months with Duo Temp.


#4: Post by mycatsnameisbernie »

When I upgraded from my Barista Express (54mm) to a Profitec Pro 500 (58mm), I had to grind much finer. For the same dose, a 58mm basket will have a shallower fill than a 54mm. I believe that results in less water resistance and a faster shot. You need to grind finer to make up for that.

With the same basket, there should be no difference between spouted and bottomless.


#5: Post by Jeff »

If your basket rim is clean, it should seal with moderate force on the handle. Exactly where depends on the exact shape and size of the ears, so a difference between the two isn't surprising. For example, La Marzocco PF handles seat at a different point than Rancilio handles. With a rubber group gasket, it may change slightly over the first month or so, as it gets a little "dented" with time. You can try a blind basket for leaks to figure out how much force you need, without losing coffee over it. Seems like you found a good spot with your later tries.

A flush of the group screen and wipe is a good habit to get into after each shot. A quick rinse of the gasket with a blind basket and the PF "rocking" in place can help to keep the gasket clean as well (end of session). There are some brushes that can help. I use the little Pallo one with a head that's about 1/2" in diameter and has a little spoon on the other end for Cafizo or your choice of cleaners.

Different baskets in the same machine (normal, VST, IMS) generally require different grinds. The same basket on two different machines can also require more subtle changes in grind.

Once the coffee extract is out of the basket, the grinds' "work" is done, so bottomless vs. spouted doesn't matter.

Supporter ♡

#6: Post by HotLava »

tennisman03110 wrote:I read you should not force the handle to turn...but maybe I should?

I grind into a cup, the pour into portafilter with funnel. Shake it a bit, then use leveler, then tamp. It's exact same I've used for 5 months with Duo Temp.
I always have to adjust my leveler depth when going from 18g to 21g baskets but I don't tamp. Not sure if that would help. I spin my leveler then tamp and readjust depth to the tamped depth. Then adjust the grind setting to that depth and you should be good for the next shot.

Also some after market baskets like IMS are very tight. It will be even tighter on a new gasket. VST fit well on the new machine.

I forgot to ask. Is the coffee old?


#7: Post by tennisman03110 »

The coffee was roasted 15 days ago. Yesterday it made a great shot with my Duo Temp.

I flush the group, clean and dry between every shot.

It seems as if the first shot might have been the gasket being the issue, which really threw me off. I'm still a bit unsure if I should crank it all the way to 6 Oclock. I got to pull real hard.

Supporter ♡

#8: Post by HotLava »

definitely. You won't damage it at 6oclock. Even a hair past is fine.


#9: Post by mrjag »

The gasket is fairly stiff from the factory so you may have to use a little more force than you would normally. Mine was stiff for 2-3 weeks... maybe a month tops. You definitely won't hurt anything locking it to 6 o'clock.

I'd also use 19g as your starting weight when dialing in a new set of beans. That seemed to work better for me than 18g -- although some beans did end up needing 18g.

Supporter ♡

#10: Post by HotLava »

I would also add that the Breville stock basket is very high quality. It is not a fast flowing basket like VST. If you decide to switch to a VST later on it will screw up your mojo again. I haven't changed any equipment for a while. But it seems par for the course that every time you change a variable there is a learning curve.