Ha ha, those things are great. You see them sometimes at Bubble Tea bars.

The Mousse al Caffe' looks interesting. Did you try any?

The Gran Caffè is really fantastic (if a little sweet). I have actually tried (admittedly not very hard) to duplicate it, but without success thus far. I think there must be some additional ingredient other than the sugar involved in making the mouse - or possibly a special tool. I haven't tried anything else on the menu as I find consuming more than one espresso at a time a bit hard on the system and Rome is a long way to go for coffee on a regular basis .

http://www.youtube.com/watch?v=cSk9R84Vd_Q


Video embedded by moderator. Video has Italian text only.FYI

bidoowee wrote:Additionally, there are plenty of parts in the machine that are not plated. In the aurora, in addition to all the exposed pipe fittings, there is a chamber directly behind the group which holds roughly a shot's worth of preheated water. For obvious reasons, I now flush the group to replace that water when I come down to make coffee in the morning!

samuellaw178 wrote:
Hi Thomas,

I was going over your awesome thread and read the above quoted. When you said you flush for obvious reasons, it wasn't quite obvious to me.... Were the chamber leaded in any way?

Hi Sam

This is interesting actually - I thought I would answer your question in the thread.

A while ago I got some unofficial test results back from a friend of mine with "access" to a mass-spectrometer on some brass samples from my original Aurora and some parts I had made in China.

I was pleasantly surprised to find that the brass used for the grouphead of the Aurora contains relatively small amounts of lead. Definitely less than 1% and possible quite a bit lower than that (as the result was within the margin of error for this testing method). So, at least as far as the Aurora group goes, Brugnetti were scrupulous and it seems likely that all the castings made by Brugnetti (including the brew reservoir) would be made from the same low-lead alloy. The provenance and composition of the rest of the plumbing fittings however, is anyone's guess. That was the good news. The bad news is that the alloy also contains arsenic.

Arsenic, phosphorus, antimony, bismuth, aluminum and silicon are used to inhibit corrosion in brasses with high zinc composition. The first two have been around for long time (possibly a very long time - bronze age?). Silicon is a more recent addition to brass/bronze alloys and seems to be the way forward as it provides protection against corrosion and maintains reasonable machinability. There are a number of so-called "eco-alloys" that have been developed in the last few decades as a response to both increasing public awareness and legislation. On that list of corrosion inhibitors there are things that are bad for you, arsenic being an obvious one. Unlike the lead, (which tends to crystallize close to the surfaces of the casting and leach into the water along with the zinc) the arsenic may be more evenly distributed through the metal and tend to stay where it belongs (i.e. not in your coffee). Arsenic is NO LONGER allowed as a corrosion inhibitor in brass used in potable water applications in California, the EU and Japan among others. All that to say and in IMHO, it is probably best to flush the brew reservoir if the machine has been idle for any length of time.

bidoowee wrote:Hi Sam

This is interesting actually - I thought I would answer your question in the thread.

Thomas, thanks for the insightful response! Do you happen to know what's the arsenic content % in the alloy? I tried to read up more on arsenic leaching or the commonly used % but couldn't find much. Most of the leaching works were done on lead. I was also shocked to discover that arsenic is more common than I thought,and can potentially be found in vegetable, seafood and drinking water. Regardless, I will definitely be more diligent in flushing after this!

JohnB. wrote:http://www.youtube.com/watch?v=cSk9R84Vd_Q

Ok, that is funny. One thing I can say for sure : there are a couple more ingredients in Mousse al caffe than they put in the Gran Caffe at St Eustachio!

samuellaw178 wrote:Do you happen to know what's the arsenic content % in the alloy?

The things you don't want in your coffee in the Brugnetti alloy were arsenic 2%, aluminum 1% and lead <1%. While this is not an official test result, it does seem to indicate the presence of these elements in the vintage brass. This is also a very small sample - exactly one group was tested - who knows whether the brass composition varied over time. However, given the necessity of protecting the brass from corrosion and that arsenic was the corrosion inhibitor of choice until recently, the chances are high that it is present in most if not all vintage brass. The same test on the "eco-brass" I am using gives results that closely correspond to the advertised composition and indicate that the undesirable elements are not present.

Thank you Thomas! This is really good info to know not easily found elsewhere.

bidoowee wrote:The things you don't want in your coffee in the Brugnetti alloy were arsenic 2%, aluminum 1% and lead <1%. While this is not an official test result, it does seem to indicate the presence of these elements in the vintage brass.

Yes but how long is the water in a dipper style spring lever in contact with the brass in the group? How long would it take for the arsenic or lead to leach into the water? Since this isn't a saturated group I'd be more concerned with the boiler then the group.