This sounds like quite the wormhole, I'm seeing so many issues that could throw away all results. Is a test even worth the time considering all the literature and tests that are available on this subject?

Spitz.me wrote:EDIT

I shouldn't have said that 'familiarity with the bean or blend doesn't matter'. What I meant was familiarity with the coffee doesn't change the argument.

It seemed to me that Jim was suggesting you become more attuned to the nuances of a bean after having tasted several shots, something which matches my own experience. I would agree that one maybe loses and reacquires some of that sensitivity.

So, even if you are already familiar with a bean and roast and are aware of its characteristics some of this would I agree still apply. We are all together up to this point.

But I am also talking about the characteristics of the previously used bean lingering. I will concede one might be more sensitised to them for the same reasons Jim mentions, but it seems unlikely one would sort of "hallucinate" them, and that is where I don't believe the opinion holds up.

What I describe involves the "new" bean initially being to some extent overpowered or diluted by the characteristics of the previous coffee bean for the first series of shots, then only several shots later gradually emerging in its full power or clarity while those of the previous bean also recede.

It seems to me that this does not totally fit Jim's scenario, even conceding one could be more sensitised or "tuned in" to the characteristics of the previous bean than the new one.

Or have I missed something incredibly obvious but crucial here?

Incidentally, I can see the relevance of Jim's comments about percentages and blends since that's effectively what this contamination is, just as I could see the relevance of Tekomino's comments about possible contamination by coffee oils in the espresso machine and agree we are of course talking very small amounts I have no way of easily quantifying. Be that as it may, the taste is there. Not always in the same way or for the same amount of shots, but always to some extent.

drgary wrote:I've also been thinking about the theoretical issues. Jim, have you read anything that discusses an ability to calibrate tasting ability based on familiarity with a mix of flavors?

Michael has claimed a level of tasting acumen and memory that are undocumented in other human beings; he has also repeatedly rejected the more physiologically likely explanations for his tasting experiences. So there is no point in doing any research about his claims on anyone except him; we already know that nobody else can do this.

If I had the sort of taste discrimination Michael claims, I would go to the nearest sensory evaluation lab and have my abilities documented. Then I would get a sports or literary agent, and sell my Lloyd's insured nose to the highest bidding perfume or food company.

Jim, I don't think I have rejected what you say out of hand, though you have subjected my posts here to consistent misreadings and ridicule.

I would find your opinions here more convincing if you were not a single-doser who frequently changes beans.

But thanks, I am honoured. As are my friends and acquaintances, both hobbyists and in the industry, who share this incredible ability. We always knew we were special.

I believe another set of questions has arisen that can migrate to a new thread. Those questions address the thresholds at which knowledgeable people can reliably discern tastes and when their sense impressions start to merge with expectations. Here's the new thread:

What Are the Thresholds of Reliable Tasting?

Gary: a very useful move and a great thread resulting. It is very much to your credit that you have kept your head here.

I on the other hand owe everyone an apology: my original post was not only poorly expressed but incorrectly expressed. Subsequent posts clarified some of the context but not explicitly. There is no excuse for that: it was a case of the more haste the less speed and we all got nowhere, wasting each other's time and blood pressure in the process.

But there is I believe something to learn from how the situation deteriorated if we want to make this forum a friendlier and more helpful place that reflects our passion for coffee positively and helps people learn. If you consider how this went for a thick-skinned person like myself who has frequented this forum actively for ages, it would have been very negative for a newbie or silent poster who is uncertain how to express all aspects of their coffee practice or to understand the technical terms used here. Sometimes we may get further by probing a situation before judging.

On to the specifics: I was talking about two different things, one with respect to single dosing ad one to using a grinder like the Nino with at least 100-150g of beans in the hopper. The original post conflated them,

For single dosing, I was stating a sacrificial "purge" dose was desirable when swapping to a different bean. Jim confirmed how this is done when he is cupping.

What the original garbled post then went on to observe without the necessary clarity and in fact switching between the single and hopper dosing scenarios in a way that single-handedly caused all the confusion was that in single dosing the purge is required because there will be some bean and oil residues on and between the burrs etc., albeit small. But at the same time I mentioned how many shots it takes in hoppered usage to trasition completely to a new type of bean. In later posts it should have become clearer to everyone that it was this I was referring to, but by then everyone had taken up their interpretations/positions and no one (including myself) was asking is this a case of bad expression/misunderstanding?

So here for the record is the very banal observation I was making about hoppered use on the Nino and other timer dosing grinders:

If anyone has bothered to read this far and doesn't know what this "hoppered" use of a timer doserless grinder means, the Nino grinder measures out a dose automatically through a chute; it doesn't have a doser, but a timer which simply switches the motor on and off - around 3 seconds for a double dose - so you need to keep a minimum of around 100-150g in the hopper for the grind and the dose to remain consistent. This is also how they are used in cafes.

This need to maintain a minimum level is why "hoppered" use is not suitable for people wanting to change beans frequently and why I was writing about it taking sooooo many shots to transition completely from one bean to another. When you hit that minimum level you can either throw all the remaining beans away and empty the grinder completely before changing to your new bean or you can simply add the new beans to the hopper and wait for the first lot to finish and the second to come through. I do the latter and so do many bars (the better ones will not serve the transition "blend"). Obviously, you do not get a straight changeover, even if you add the first layers of new beans very gently by sprinkling them on top. There is some mixing of the two "layers" as the beans move down through the narrowing hopper and within the burr chamber. I would have expected only several doubles but it tends to be more. However this is clearly not the small contamination Jim and others thought I was referring to but a much coarser transition from 100% of one bean to 100% of another in "hoppered" use.

Comically, the inference was that I was claiming to perceive carryover across 150g of shots in single dosing or with a fully-emptied grinder or something like that, despite being known on this board as someone who is at least occasionally sane and a truthful reporter of what he finds and occasionally even verifies.

I should have taken more time to express myself clearly, there's no doubt about that. Just as there's no doubt that we could all learn from how Gary alone has responded.

Thank you, Michael, for clarifying. Thank you also for the humility of your correction. And you were writing all along about a hopper loaded with beans with the new ones poured on top??? That's priceless!

Ah, now I get it. I'm almost sorry to leave the alternate reality of tasting parts per million

When commercial places switch over, they usually close the trap door at the bottom, lift out the hopper, grind through all the remaining beans in the grinder throat, empty the hopper of old beans, and refill it with the new beans. Then they grind a sacrifice shot through, and are ready to go -- at the cost of about 1/4 to 1/2 pound of wasted coffee. If you just add the new beans, you will get a long transition where there are significant percentages of the old beans in the mix.

But this misunderstanding has brought something new to the fore: We do learn to better discriminate with experience; and this has never been properly considered when talking about the experience of using a given coffee over time. It puts a new spin on people's ideas of how the taste changes with dialing-in or aging. Am I really improving the dial-in when a coffee "tastes like itself" after the second or third tweak of the dose and temperature, or have I just gotten properly attuned to it?

drgary wrote:Thank you, Michael, for clarifying. Thank you also for the humility of your correction. And you were writing all along about a hopper loaded with beans with the new ones poured on top??? That's priceless!

I think this is hilarious! Interesting that you didn't catch this earlier while we were all trying to understand how it takes 150g of new coffee to taste the new coffee. You just kept keepin' on! haha Now I get it, it takes a 'hopperful' to get to the new coffee.

I agree with Jim, this has brought to light some thoughts I know that I've never thought of before. These new ideas are quite interesting to me.