Coffee Machines

[apelike]

15 hours ago, Pettytom said:

I’ve just told you how heat affects them.

 

Many of the molecules that make up the flavour of ground coffee are either aldehydes, ketones,  esters, or organic acids. There are quite a lot of them though and their interactions are pretty complex.

No you have stated that heat affects them but not how. I know there are a lot of compounds/molecules that make up the aroma and taste and also know that a lot of them are can be changed due to high heat above the boiling point of water but so far nobody can tell me what ones are changed by the heat or how.  Some are not changed at all as it takes very high temperatures above boiling point to affect them. As said, people are just repeating parrot fashion what they have heard others state without questioning it. What I am doing is questioning that attitude.

 

15 hours ago, Pettytom said:

That’s why I referred you to the RSC website. If you register, you’ll get free access to a couple of interesting papers.

But being so compex a matter a few papers will not do, and BTW I have read several and stand by what I have said above. It takes high pressure water at a temp of 175C to make instant soluble coffee so something here is not right as at that temp according to some the coffee should turn out very bitter.

[Pettytom]

17 minutes ago, apelike said:

No you have stated that heat affects them but not how. I know there are a lot of compounds/molecules that make up the aroma and taste and also know that a lot of them are can be changed due to high heat above the boiling point of water but so far nobody can tell me what ones are changed by the heat or how.  Some are not changed at all as it takes very high temperatures above boiling point to affect them. As said, people are just repeating parrot fashion what they have heard others state without questioning it. What I am doing is questioning that attitude.

 

But being so compex a matter a few papers will not do, and BTW I have read several and stand by what I have said above. It takes high pressure water at a temp of 175C to make instant soluble coffee so something here is not right as at that temp according to some the coffee should turn out very bitter.

Maybe if you asked a specific question about a specific reaction, you’d get a better answer.

 

At the moment, you are being very general and that is resulting in generalised replies.

[Obelix]

1 hour ago, apelike said:

But being so compex a matter a few papers will not do, and BTW I have read several and stand by what I have said above. It takes high pressure water at a temp of 175C to make instant soluble coffee so something here is not right as at that temp according to some the coffee should turn out very bitter.

It does?

 

You mean spray air drying or vacuum expansion freeze drying are not used? Or are you thinking of supercritical decaffination methods that do involve taste changes?

[Pettytom]

11 minutes ago, Obelix said:

It does?

 

You mean spray air drying or vacuum expansion freeze drying are not used? Or are you thinking of supercritical decaffination methods that do involve taste changes?

A brief spell of googling reveals that Carte Noir Classique is made by brewing coffee in the normal way and then freeze drying.

 

Therefore there is no mystery about the retention of flavour, or the lack of bitter compounds.

 

So, Apey, you can rest easy now. No high temperatures are used in the production of your instant coffee.

[Obelix]

Freeze, sublimation drying, spray, elevated spray dry are the methods used. I've tried all of them. Sadly vacuum sublimation despite being excellent does take off some of the flavours that can be condensed out and returned but it's a PITA.

 

I dont know any method of using hot water at 175C (which would involve very high pressures to be feasible - at least 3MPa to be safe). I also cannot see why it would be needed since you want to remove water not add it...

[Padders]

Some proper coffee connoisseurs on this topic, I'm afraid you have me completely bewildered, it's a bit like Quantum physics of coffee.

I have just had a sachet of Nescafe original unsweetened taste 2 in 1 (6 for a pound) beautiful.

[Pettytom]

4 hours ago, Padders said:

Some proper coffee connoisseurs on this topic, I'm afraid you have me completely bewildered, it's a bit like Quantum physics of coffee.

I have just had a sachet of Nescafe original unsweetened taste 2 in 1 (6 for a pound) beautiful.

But, did you use boiling water, Padders?😀

[Padders]

5 minutes ago, Pettytom said:

But, did you use boiling water, Padders?😀

Actually it says on the packet... use hot but not boiling water...so I boil the kettle, leave for about 30 secs ,then pour. taste right enough for me.

 

[apelike]

20 hours ago, Obelix said:

I dont know any method of using hot water at 175C (which would involve very high pressures to be feasible - at least 3MPa to be safe). I also cannot see why it would be needed since you want to remove water not add it...

 

Sorry wiki must be wrong then which of course is possible, scroll down to extraction. Notice I did also state in my post that it was water at high pressure as well.

 

 https://en.wikipedia.org/wiki/Instant_coffee

 

 

[apelike]

6 minutes ago, Padders said:

Actually it says on the packet... use hot but not boiling water...so I boil the kettle, leave for about 30 secs ,then pour. taste right enough for me.

The Carte Noire says the same as well but I have only just read that and despite it still use boiling water. I suppose its a matter of taste...