cuznvin Senior Member Joined: 6 Oct 2011 Posts: 400 Location: NY Expertise: I love coffee
Posted Fri Dec 21, 2012, 12:49pm Subject: Stainless vs Copper
I am wondering if it makes that big of a difference if some companies are using stainless vs copper boilers. On the Dream T, the brew boiler is copper (actually a combo of brass, copper and stainless) and the steam boiler is stainless. Is this a cost saving measure? should I only consider buying machines that use two copper boilers only (DB)??
MJW Senior Member Joined: 25 Jul 2012 Posts: 74 Location: Silicon Valley Expertise: I love coffee
Posted Fri Dec 21, 2012, 1:33pm Subject: Re: Stainless vs Copper
I don't think it makes that big of a difference, because there are well regarded machines such as the LM GS/3 and current Cremina, that use a stainless steel boiler. The GS/3 portafilters are also now made from stainless steel.
The metal properties are very different, and people have made a big deal out of copper's high heat conductivity. But the existence of these new designs (and probably some old designs as well) proves that a successful design can be made with either metal.
cuznvin Senior Member Joined: 6 Oct 2011 Posts: 400 Location: NY Expertise: I love coffee
Posted Fri Dec 21, 2012, 1:43pm Subject: Re: Stainless vs Copper
MJW Said:
I don't think it makes that big of a difference, because there are well regarded machines such as the LM GS/3 and current Cremina, that use a stainless steel boiler. The GS/3 portafilters are also now made from stainless steel.
The metal properties are very different, and people have made a big deal out of copper's high heat conductivity. But the existence of these new designs (and probably some old designs as well) proves that a successful design can be made with either metal.
I did read something somewhere that stainless can hold on to bacteria.. My guess is that is the reason La Spaziale used stainless for the steam boiler and not the brew boiler. The high temp in the steam boiler kills any bacteria..
emradguy Senior Member Joined: 31 Mar 2011 Posts: 1,696 Location: Houston Expertise: I live coffee
Espresso: Izzo Alex Duetto II Grinder: MacapM4T, Macap M4, OE Lido,... Drip: Espro press; Aeropress Roaster: internet
Posted Fri Dec 21, 2012, 4:02pm Subject: Re: Stainless vs Copper
The temp in the brew boiler is also sufficient to kill every known human pathogen. In fact, it's considerably hotter than your automatic dishwasher, which only heats to about 135F. I wouldn't lose another second of sleep over the bacteria "issue". btw, to add to my credibility...I have a BA in cellular and molecular biology, with a minor in chemistry...and am an MD.
cuznvin Senior Member Joined: 6 Oct 2011 Posts: 400 Location: NY Expertise: I love coffee
Posted Fri Dec 21, 2012, 4:23pm Subject: Re: Stainless vs Copper
emradguy Said:
The temp in the brew boiler is also sufficient to kill every known human pathogen. In fact, it's considerably hotter than your automatic dishwasher, which only heats to about 135F. I wouldn't lose another second of sleep over the bacteria "issue". btw, to add to my credibility...I have a BA in cellular and molecular biology, with a minor in chemistry...and am an MD.
Coffeenoobie Senior Member Joined: 11 Dec 2011 Posts: 2,313 Location: PNW Expertise: I like coffee
Espresso: N S Oscar Grinder: Vario W
Posted Fri Dec 21, 2012, 4:33pm Subject: Re: Stainless vs Copper
emradguy Said:
The temp in the brew boiler is also sufficient to kill every known human pathogen. In fact, it's considerably hotter than your automatic dishwasher, which only heats to about 135F. I wouldn't lose another second of sleep over the bacteria "issue". btw, to add to my credibility...I have a BA in cellular and molecular biology, with a minor in chemistry...and am an MD.
cuznvin Senior Member Joined: 6 Oct 2011 Posts: 400 Location: NY Expertise: I love coffee
Posted Fri Dec 21, 2012, 4:51pm Subject: Re: Stainless vs Copper
The temp in the brew boiler is also sufficient to kill every known human pathogen. In fact, it's considerably hotter than your automatic dishwasher, which only heats to about 135F. I wouldn't lose another second of sleep over the bacteria "issue". btw, to add to my credibility...I have a BA in cellular and molecular biology, with a minor in chemistry...and am an MD.[
I should have guessed you are a radiologist (emrad) ... I used to do MRI Applications..
Posted Fri Dec 21, 2012, 5:12pm Subject: Re: Stainless vs Copper
cuznvin Said:
The temp in the brew boiler is also sufficient to kill every known human pathogen. In fact, it's considerably hotter than your automatic dishwasher, which only heats to about 135F.
Although brew boiler temperatures (195-203F) are sufficient to kill most vegetative bacterial cells, much higher temperatures are required to kill bacterial spores (which are like bacterial "seeds"). Temperatures around 250F for many minutes are required to kill the spores of Clostridium botulinum, the bacteria that causes deadly botulism.
It would be virtually impossible to contract botulism from an espresso; nevertheless your statement above is flat out wrong.
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