AndyS wrote:Interesting <scratching head>

I second Dan's experience with the Linea versus the Aurelia; it takes a lot of sessions to get proficient. However, the GB5 and GS3, while not as easy as the Aurelia, may make it in two hours; they are a good deal more walk up friendly than the Lineas. A lot of this may be about simple things -- better initial "coldnose" management and smaller gicleurs on the newer LM models.

I got an hour on the GS3 at Intelly, and it has a far sweeter disposition than the older LMs

As I said before, the DB versus HX difference is very low on my list of deciding factors in espresso machines.

HB wrote:1. It's margin of error is quite small.
2. No. Perhaps if it were two weeks from now, I might reconsider. Maybe.

It's anecdotal evidence, but as an example, I tried the evaluation model Aurelia at Counter Culture awhile back and pulled good to very good shots from the get-go with no fuss, no muss. That just doesn't happen with the La Marzoccos in the main lab, I don't know why. It will be interesting to see how this changes the competition now that Nuova Simonelli is sponsoring the WBC, e.g., it may prove more difficult for a competitor to stand out on technical acumen alone.

I dunno about the machine in CC's lab, but mine is about the most ridiculously easy to use machine that I've ever come across. Perhaps it's due to updates in the design over the last several years. I'd expect the GB5 with Peirro group caps to be similarly easy.

-Greg

I just plowed through all 7 pages of this in-depth discussion, plus Dan's great write-up ("How I Stopped Worrying and Learned to Love HXs"). I imagine you all might feel like every molecule of flavor has been extracted from this topic and also it's now six months later, but I have a question that, as far as I can tell, was not addressed in either place.

My question has to do with the stale or "dead" water that sits in the double boiler, a situation that reportedly does not occur with the heat exchange machines. Is that significant enough for me to disband thoughts about a double boiler?

I am a cappuccino/latte lover who is researching the purchase of my first-ever espresso machine, having settled the grinder-end of my investigation. At the moment I need a non-plumbed machine because I'm renting, though that may change in the next year or two. I'm willing to go up to the $1700-1900 range, possibly up to $2200 if the reward is great.

I was ready to pursue buying a double boiler because of the milk frothing/steaming capability and lower learning curve, but then I read a blog by Kat at Seattle Coffee Gear dated 3-1-09, around the same time that this forum discussion began, and also I talked with her on the phone yesterday. She said that the Italian espresso machine makers stopped making double boilers for commercial use in the 1970's and since then have been making them only for home use. Also, she talked about the "dead" water, or residual, that sits in the double boiler until the next batch, whereas the heat exchanger is constantly cycling fresh water through the siphoning system. This is not the same as having spring water sitting in plastic jugs, because the water can or does interact with the boiler. The link to her blog is below. Of note, Seattle Coffee Gear sells both kinds of machines, with the idea that there's a home for each.

I'd appreciate any comments anyone can offer.
Ann

http://blog.seattlecoffeegear.com/seatt ... oiler.html

ahhh... the stale water myth! always a good one.

Can water go stale?

And... as has been said a million times before... do not trust what equip makers tell you about their rationales for their decisions. The truth is that you DO need to backflush your machine with detergent etc. (90% of all equip decisions made by manufacturers is driven by cost and margin - and then post-rationalized with ridiculous justifications like this).

Straight water pulled through the group tastes of coffee regardless of HX or DB. Neither taste like fresh water.

Since heat exchange machines are continuously cycling fresh water through their siphoning system, they have an improved mineral balance and cannot become stale like the water in the double boilers might. So the flavor is significantly better and, therefore, preferred by connoisseurs the world over.

Heat exchangers cycle the same water through the heat exchanger until a shot is pulled. I seriously doubt a few parts per million change in mineral content while the water is in a double boiler is detectable by taste when the water is polluted with coffee and milk.

From La Marzocco, Italian Dual Boiler

The key feature of all our coffee machines is the dual-boiler technology.

To achieve a faultless quality in the cup we use a boiler dedicated to coffee brewing that is entirely independent of a second boiler used exclusively for steam and hot water for tea or other beverages.

This system, unlike the traditional system with a single boiler used by most coffee machine manufacturers, ensures a unequalled thermal stability, the determining factor for achieving a satisfying result in the cup.

Another advantage of the dual boiler is the quantity and quality of the steam dispensed, greatly superior to any other coffee machine

She said that the Italian espresso machine makers stopped making double boilers for commercial use in the 1970's and since then have been making them only for home use.

This is completely false. La Marzocco, an Italian company, has been make dual boiler machines for commercial use for decades. You'd think Seattle Coffee Gear would be aware of this.

Thank you Malachi, Ian and Beezer for being so quick and helpful, and for debunking the stale water myth (I like your humor). I looked up the Marzocco link per Ian and Beezer, had a little fantasy-thought about the GS3 and then read Dan's comments that it's not very user-friendly for newbies, and finally I spoke with Phil at Caffe Lusso.

Phil is a proponent of dedicated boilers and calls the Marzocco GS3 the "Ferrari" of home espresso machines. He said nearly every good micro-roaster in the U.S. is using a dedicated boiler (specific for every group head). Another myth debunked. Also, he said the Marzocco and most, if not all, the double boilers, are made of stainless steel, so unlikely to interact with water stored in it. Last, was his comment that the quality of the water is much more significant than the sitting of it (my paraphrase).

So unless there are other comments to come, I thank the three of you for your time and your help. I think this question has been put to rest, at least for me.
Ann

Whatever your boiler type, it is a good idea to drain it every week or two to prevent mineral buildup. This is especially true in a boiler used for steaming (e.g. THE boiler in a HX machine; the steam boiler in a dual boiler machine).

Water becoming "stale" in a boiler is one of those myths handed down from on high and propagated across the ether, that few people ever think enough about to question, or to demand proof of.

ken

Ken, thank you for chiming in. Those are very helpful notes about back-flushing and draining (from Malachi and Ken). Also, I would think if the double boiler is used regularly that it will automatically become empty approx. a couple of times a week.

This myth seems to have been well and truly debunked, even dunked!

I find these forums to be a treasure-box full of help and support, which is what I've found with the four of you. My thanks to you all.