Brand New Breville Dual Boiler: Pressure Profile Issues and Other Questions

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kinda-niche

#1: Post by kinda-niche »

I received my brand new BDB yesterday and have been trying to dial in a new bag of beans that I have never used before (it's on the lighter side of things). I have the BDB paired with a Niche Zero. Long story short, something weird is going on with my pressure profile: after the first several shots, where the pressure seemed to be in the ideal/vanilla 8-10 bar range (mostly around 9), I am suddenly getting a pressure profile that barely even hits 7 bars and quickly tapers off via a 6-5-4-3 bar progression. My dose has been 18-18.5 g throughout and I am sitting at the middle of Niche's "espresso range" (say, around setting #15). I am following a decent puck prep routine that involves WDT with a homemade tool. Any idea what might be happening? Any solutions/proposals for diagnosis?

Secondly, what dose is the BDB stock double basket rated for? I know they say 19-22 g, but what dose range have y'all had success with? Asking especially for lighter roasted third wave specialty coffees (so high-grown, high density profile, if that makes any difference).

Lastly, the steam wand seems to be getting super hot (except for that rubber handle meant for maneuvering it) where accidentally touching the metal parts/tip is a serious burn risk. Is this to be expected?

P.S. - May I also say that the machine is hella loud?! I wasn't expecting this much vibration and noise during the shots LOL. But it seems to be a really nice and capable machine so far!

j_bravo14

#2: Post by j_bravo14 »

Just had my BDB for a few days. Coming from a commercial grade e61 HX, I feel that the pump of the BDB is louder compared to my e61.

Pressure wise never had a problem. Weird behavior though when I tried a very long pre infusion (25 sec) after which when the pressure ramped up it hit 9 bars then started going down to ~7 bar mark. It may be due to bad puck prep.

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cafeIKE
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#3: Post by cafeIKE »

Unless the Niche is making large clumps, no WDT required. Just distribute and tamp <- L E V E L

Does the pressure hold on a blind basket? If yes, look in the mirror. That's where the problem originates.

Does the shot get thin and watery as the pressure drops with more flow OR does the color and consistency remain good but the flow diminishes? If the former, the puck integrity is bad and it's channeling. If the latter, the pump circuit has a problem.

As far as basket capacity, it's whatever makes the best shot. 17g ground on 12 maybe the bee-knees. OTOH, 18.75g ground on 16.75 may tickle your fancy. IMO, dose steps are 0.1g with 0.05g accuracy. Doses may change daily depending on the coffee, storage method and the weather.

Puffing the niche pays dividends if regimen is single shots at hours long intervals.
Huffin' & Puffin' a [Niche Zero] grinder

martinngyh

#4: Post by martinngyh »

Assuming your beans are fresh (within 4-30 days of roasting, not best sell-by date) and your puck preparation was good, it sounds like a dialing-in problem or burr seasoning problem. Set the grinder to finer grind setting. Purge at least half or one does. Re-prepare the puck.

I have been sticking to 18 g. This does works for most of the beans.