Breville Dual Boiler woes

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

#1: Post by Undercaffeinated »

I've been using a Dual Boiler that I purchased off amazon for about a month and a half now. Up until 2 weeks ago, I was able to pull consistent shots using the double shot(double walled) basket at or above 7 bars. It didn't matter much what beans I was using. Suddenly though, they're bouncing between 3-5 bars using the same basket and nothing I can find has changed. Using the cleaning disc it runs up to 9 bars, if I run it several times in a row it will start getting to 10 bars. I'm new to espresso but it was very consistent before. I ran out and bought freshly roasted beans and had them ground for espresso but it hasn't made a difference. I managed to choke the machine but still didn't get above 5 bars during that run. Any insight is appreciated.

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#2: Post by johnny4lsu »

had them grind them for espresso
You really need your own grinder. You can't have someone "grind for espresso"...It just doesn't work like that. If you were getting anything decent with someone grinding for you, it was pure luck of the draw.

You can get a Baratza Sette for fairly cheap or a Niche Zero for a little more.


#3: Post by Undercaffeinated »

Thanks Johnny, I do need a better grinder than what I currently own. It's confusing to me how with just the basket in it will get 5 bars but with espresso it will only reach 3. I do feel the extraction is coming out earlier so I'll pick up a grinder and maybe a better tamp and experiment from there.

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#4: Post by lancealot »

4 baskets came with your BDB.
- single shot, single wall
- single shot, double wall
- double shot, single wall
- double shot double wall

I would estimate that almost none of us has experience with the double wall baskets. I used mine 1x. Mine are packed away now.

The double wall baskets are for when you have pre-ground coffee. They work by having a lot of resistance to flow so that the coffee does not have to provide this, most times, preground coffee cannot. The single wall baskets have very little resistance to flow - as in none. You use fresh ground coffee and it provides the necessary resistance.

Your post makes it sound like you used to be using the double shot - double wall basket and now you are mistakenly using the double shot - single wall basket.

3 more things.
- Have you read your manual cover to cover and made sure you understand it all?
- Are you following the maintenance suggestions.
- Backflush the machine weekly instead of when it tells you to do it.

Good luck

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#5: Post by johnny4lsu »

Great points lancelot. Didn't even think about that angle.


#6: Post by Undercaffeinated »

I have been using the double shot and double walled basket because it is more forgiving. I have used the single shot - single wall basket with the beans I got locally roasted and was able to get 9 bar when I first got the machine. Mostly I stuck with the double wall basket because it worked better for the non-local beans i have. For a month and a half I've been able to consistently get 7 bar every time with the double walled double basket.

-I read the manual cover to cover
-I have been backflushing the machine regularly
-I ran a cleaning tablet through just to be sure.

Here is a video with the backflush disc inserted.

I'll pick up a new grinder and experiment with it. Hopefully that fixes my issue though I'm not sure why the pressure during the backflush can't make 10 bars anymore.

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#7: Post by lancealot »

Totally get the reason for using the double wall basket. I hope I didn't come across as judgmental.

Thanks for the viddy. Lookin and sounding good. I have no idea why you used to be able to make 10 bar with the blind disc and now it only gets to 9. There is a valve just down stream from the pump called an OPV - Over pressure valve. It limits the pump pressure. Without it these pumps max out around 17 bar or so. Maybe it "broke-in". It is adjustable, you can find more deets if you search the forum BUT... I wouldn't mess with it. Looks just about perfect where it is.

Good luck with the new grinder. With this level of machine, a dedicated grinder is where it is at.

Keep askin questions, keep posting viddy's. We will help out if we can.

tracer bullet

#8: Post by tracer bullet »

My experience with pressures is that it's about 9.75 or so with a flushing disc to equal 9 even with actual coffee in the portafilter (assuming a reasonable flow rate like 2 ounces / 25-30 seconds). That little bit of water flow through the puck drops the pressure compared to the solid disc.

That said, agreed, you're probably OK. If you want you could up the OPV a touch, generally screwing clockwise (aka tighten) to increase the force ont he spring inside, but I wouldn't get overly concerned about it.


#9: Post by Undercaffeinated »

I received the sette 270 today from baratza and it made all the difference in the world. I was surprised at how course I had to grind it not to choke the machine with the single wall basket. Still dialing in the grinder to get it perfect but I'm happy it wasn't a problem with the machine. It makes me think the old grinder wore really fast and wasn't grinding as fine. Thanks again for the help and making me realize I was an idiot for not investing in a good grinder.


#10: Post by IMAWriter » replying to Undercaffeinated »

No worries, we've all had to be coaxed in the beginning. Im a former CG moderator who mad folks sick with mantra of answering questions with GRINDER FIRST! haha
Give that Sette about 5-8 #s through it to get TOTALLY consistent. At 5 #s, do the cleaning as described in the video. Apologies for the off topic.
LMWDP #187