Third Brew

The third experiment began with what I believed would be the rather uneventful business of repeating the second.

This was intentional.

Yesterday's coffee had come remarkably close to perfection - or at least to that modest and entirely personal variety of perfection which means that I drank it happily and could think of no immediate reason to interfere with it. Thirty-four grams of coffee. Five hundred grams of water. Grind setting twenty-six. Sixty seconds in the upper chamber. The resulting cup had been clean and light, distinctly floral, without bitterness, and sufficiently strong to endure the addition of cream and sugar without disappearing beneath them.

There seemed little reason to improve upon it.

And so, for once, I did not try.

There was, however, one difference.

The coffee I used today had been ground two days earlier and kept in the refrigerator.

This had originally been a matter of convenience rather than experiment. I had coffee already ground at the proper setting, and it seemed wasteful to discard it merely because forty-eight hours had elapsed.

Coffee, as it turns out, keeps its own opinions on such matters.

I prepared the siphon precisely as before.

The same quantity of water entered the lower globe. The same quantity of coffee waited above. The flame was lit, the water made its now-familiar ascent through the glass tube, and the whole apparatus performed its little act of domestic physics with reassuring familiarity.

There is already something curious happening here.

Only three brews ago the siphon seemed a complicated collection of glassware requiring my complete attention. I watched every movement suspiciously, rather as one might supervise an unfamiliar tradesman who has arrived with a large wrench and begun dismantling the plumbing.

Today I simply made coffee.

The ritual is becoming familiar.

The result was not.

My first impression was of bitterness.

Not an unpleasant or aggressive bitterness, but certainly more than yesterday. The coffee remained exceptionally clean in the mouth, possessing none of that heavy coating sensation I have begun to recognize as separate from strength, but the balance had shifted.

More curious still was what had disappeared.

There was no acidity whatsoever.

Yesterday I had been able to detect a gentle sourness, particularly as the coffee cooled. It had never become objectionable, but it was unmistakably present and seemed part of the changing character of the cup.

Today there was nothing.

No brightness. No sharpness. Not even the smallest suggestion of sourness while the coffee was hot.

And the flowers had vanished.

Yesterday's cup had possessed a distinctly floral aroma - one of those descriptions I had previously regarded with mild suspicion when printed upon coffee packaging. I had been rather pleased to discover that floral was not merely a word employed by people determined to make coffee sound more complicated than necessary.

Today I searched for it.

Nothing.

I smelled the cup again.

Still nothing.

The coffee smelled like coffee.

This is ordinarily a perfectly acceptable quality in coffee, but having discovered yesterday that it was capable of considerably more, its sudden reticence was conspicuous.

As the cup cooled, the bitterness remained. A very slight sourness eventually began to appear, though so faintly that I might have overlooked it entirely had I not been deliberately searching for changes. The floral aroma did not return.

The coffee was still good.

That seems important to record.

It would be easy, once one begins paying close attention to such things, to turn every difference into a defect. Today's cup was not bad coffee. It was clean, pleasant and perfectly drinkable.

It was simply less interesting.

And because the recipe had remained unchanged, there was one obvious suspect sitting before me.

The grounds themselves.

Brew No. 3

Coffee: 34 g
Water: 500 g
Grind: Zwilling setting 26
Upper-chamber brew: 60 seconds
Coffee condition: Ground approximately two days earlier and refrigerated

Black, hot: Clean and pleasant, though noticeably more bitter than Brew No. 2. No detectable acidity or sourness.

Aroma: The floral character of the previous brew was absent.

Black, cool: Still clean and somewhat bitter. A very slight sourness began to emerge as the temperature fell, though considerably less than in the previous brew. Floral aroma remained undetectable.

Overall: Good coffee, but flatter and less expressive than yesterday's freshly ground cup.

There is something rather pleasing about having accidentally conducted an experiment.

Had I changed the quantity of coffee, altered the grind, extended the brewing time, or become overenthusiastic with the bamboo paddle, there would have been half a dozen explanations for the difference.

But I had done none of these things.

The principal alteration was simply that yesterday's beans had been ground immediately before brewing, whereas today's had spent two days waiting in the refrigerator.

Apparently coffee dislikes waiting.

This should perhaps not be surprising. Grinding a bean is not merely reducing it to convenient particles. It is also exposing what had previously been protected inside it. Aromatic compounds begin escaping into the air; oxygen begins doing whatever quiet mischief oxygen does; and time, as usual, gets involved.

Refrigeration may slow matters, but evidently it does not persuade them to stop.

What interests me most is not that I have learned freshly ground coffee is preferable. I have encountered that advice countless times. It appears on bags, in brewing instructions, in articles, and from anyone who has developed sufficiently strong opinions about coffee to own a scale.

I knew it already.

But there is a considerable difference between knowing something because one has been told it and knowing it because one has tasted it.

Two days ago I would have repeated, quite confidently, that coffee should be ground immediately before brewing.

Today I know what two days can taste like.

They taste a little more bitter.

They smell less of flowers.

They are clean enough, perfectly pleasant, and somehow missing something.

Tomorrow I shall return to freshly ground beans and repeat the same recipe once again.

If the floral aroma returns, if the bitterness retreats, and if that slight brightness reappears as the cup cools, then the case against my refrigerated grounds will become considerably stronger.

Until then, I shall refrain from convicting them entirely.

But they are, at present, the only suspects.

And the evidence is beginning to smell rather less floral than it did yesterday.