happycat wrote:The OP is is triggering my troll detection. I provided a clear explanation and he has simply repeated his original illogical claims.

David,

I cannot thank you enough. Your two references (https://www.coffeechemistry.com/compari ... d-roasters and https://www.researchgate.net/publicatio ... _in_Coffee) are exactly what I have been hoping to find. Obviously you have studied and learned a great deal about coffees and roasting and making espresso. Your expertise is exactly why I log into Home Barista. Apparently I have annoyed you. For that I apologize. It is exactly opposite of anything I intended.

I think my writing has been unclear. What I am interested in is removing unwanted gas from whole coffee beans. Until last year I had never even heard about degasification. I have been drinking coffee for 65 years with the assumption that the fresher the coffee the better it will taste. The idea that coffee can contain gas that must be removed before a coffee drinker can get maximum enjoyment out of it is entirely new to me.

You write that there is a world of new experiences waiting for you if you open yourself to them. Who could disagree with that? As Don Quixote tells Sancho, "... el que lee mucho y and mucho, vee mucho y sabe mucho."

So when I purchased a second lever machine in February and began learning how to use it, degassing my whole dark roasted coffee beans was among the first steps I tried. Up until about two weeks ago I had not pulled an espresso with fresh beans. But in an effort to try to open myself up to new experiences, two weeks ago I came home with freshly roasted beans, which I immediately used to make an espresso. The result was a surprise. To my taste the espresso was more enjoyable - albeit only slightly more enjoyable - than the espresso I made with beans that had been degassed.

Of course the next time I saw my friend I discussed this with him. The explanation he offered is what we have been discussing, namely, that the fluid bed roasting method of the Mike Sivetz roaster he uses made degassing pointless.

I take your point that the Quest drum roaster you use has remained clean for over seven years. I couldn't possibly argue against this. I do not know anything about a Quest drum roaster.

Graffeo has been in business since 1935. I don't know if the old roaster in the window was used back in 1935, but it was Luciano's roaster for years before it was replaced by Mike Sivetz's roaster. I also don't know if Luciano knows anything about the Quest drum roaster.

The only thing I know is that to my taste the espresso I make with Luciano's fresh roasted whole beans is slightly more enjoyable than the espresso I make with beans that have been degassed. And my only intention in posting on Home Barista is to see if anyone might have any idea why.

Again I apologize if I have annoyed you. But it has been a learning experience.

/Charles

Can the gas be burned out of the beans?

happycat wrote:Whether or not the coffee has CO2 is irrelevant to whether you enjoyed an espresso from it.

CO2 affects solubility of coffee. So you can enjoy coffee that has not degassed but you are not getting the maximum out of it. It's just inefficient brewing. It's like enjoying an espresso when you have channeling of water through the puck. You might enjoy it, but you are not brewing the whole puck evenly. It's like any version of preparing a food item... you might enjoy it in some way and yet be wasting the full potential of your ingredients. I suppose it's possible that you might enjoy a gassy bean if the gas reduces the solubility of flavours that you don't like.

Whether your friend's whole bean coffee has CO2 in it is very easily determined. Grind it up and add hot water. Does it foam up or not? It's an easily determined thing. If there is very little CO2 it's possible that it's quite a dark roast that has blown the integrity of the bean structure so it can't hold onto gas. If so, your paradigm of coffee flavour focuses on roast flavours rather than origins. So "properly roasted" becomes a meaningless and subjective term... there is no original flavour left to enjoy that would be affected by CO2 in a lighter roast.

None of this is new or contentious. There is a world of new experiences waiting for you if you open yourself to them.

David,

I am intrigued by the distinction between roast flavours and origins. In pour over coffee I have been able to taste the origins. But espresso is an entirely other matter. I have never had an espresso made from a light roast. Friday my wife and I took our niece and nephew to one of San Francisco's esteemed restaurants. It was my niece's 30th birthday. An important dinner! After dinner I ordered an espresso. When it came it was to my taste undrinkable. The dinner was so exquisite that it raises questions about the espresso. How could such an acclaimed restaurant serve such awful espresso? Brings to mind Mark Twain's famous reply to the gang of reporters following him after he had attended a performance at Beyruth. He was asked how he enjoyed the new music. And Twain replied: "Well, I understand it is much better than it sounds."

/Charles

Sadly it's a common experience that the coffee and espresso served at most restaurants is subpar. There's been a few threads about this and some conjecture that it could even be a strategy in some cases to turn over tables and get more customers served instead of encouraging diners to hang around after dinner enjoying the coffee.