Seeking input, advice, commentary since I'm trying to choose between a brass and a stainless Penney bottomless portafilter, destined for use with a 1992 Olympia Cremina.

I have a Penney brass tamper and it's pretty and I love it but after 6 weeks of daily use I've already nicked one edge so wondering about durability of unplated brass for a portafilter.

Granted that both materials will likely last as long as needed, would like to hear any thoughts on wear (on both portafilter itself and interface surfaces of the group), useful lifespan, or general desirability of brass vs stainless in this use.

Based on searches and reading here, it appears that brass has superior heatsink properties (the original Cremina portafilter is cast, plated brass). Feel like I may be "happier" to walk into the kitchen and see shining brass espresso tools but am happy to go stainless if there's a good reason.

Heat sink issue is pretty much moot as far as i can tell for bottomless because the coffee never touches it. I would absolutely expect SS to retain its look and dimensions way longer than brass but really only in a cosmetic way. Bayonette tabs may wear faster however. Brass is easy to polish and return to a nice finish but stainless isnt impossible either. Lots of trade offs but nothing you cant live with either way. Go with what makes you happy.

meton wrote:Seeking input, advice, commentary since I'm trying to choose between a brass and a stainless Penney bottomless portafilter, destined for use with a 1992 Olympia Cremina.

The group is brass. Stainless is notably harder than brass. So at least in theory, a stainless portafilter in a brass group can contribute to wear on the lugs of the group.

You may have to put a paper shim above the group gasket in 40 years when the lugs wear a touch. Dont worry about it, get whatever you think looks best. Either will work the same.

I have one of Richard's early model brass bottomless portafilters. My only complaint is that unless you clean/polish it meticulously after each session, the brass will show water stains.

kmills wrote:Heat sink issue is pretty much moot as far as i can tell for bottomless because the coffee never touches it.

True, but as I recall, the grouphead temperature drops like a stone when I lock in a cold (brass) portafilter, whether it's bottomless or not. A portafilter made of stainless steel would take longer to heat up than one made of brass. It's not a deal breaker either way, but I would expect the warmup / flush routine would need minor tweaking depending on which material is used.

HB wrote:I have one of Richard's early model brass bottomless portafilters.

I was undecided about whether to purchase brass or stainless but then stumbled into someone selling a used brass version and replacing it with stainless. I acquired the brass for an attractive price. Debate solved. (And I know you were talking about a different Richard.)