Though frustrated, Klaas told me he agreed with the rabbi’s verdict. After many years of oversight, he had come to respect the rabbi’s expertise.

“He could literally walk the field, tasting the kernels, to get the moisture he wanted, which I’ve come to learn is 13 to 14 percent. He knew how long to wait to get it. And by God, he always nailed it.”

As we waited (and waited) for the rabbi to arrive, I considered a question I had never thought to ask before: Is there an ideal moment to harvest wheat? And can you taste the difference?

First, some facts: Wheat can be mature and still too wet to harvest. At the point that the grain reaches physiological maturity, it can contain 40 percent moisture, making it exquisitely susceptible to chametz and spoilage in storage. Left to ripen on the stalk, the wheat will continue to dry down over the next several days. The sweet spot is below 18 percent moisture — ideally closer to 13 to 14 percent, just what the rabbi was looking for. Below 10 percent, the flour won’t perform as well for baking. But waiting works only if the weather cooperates. As one farmer told me, “Every day you’re in the field longer is more risk you’re taking.”

As a rule, wheat farmers don’t take risks. Which is why in regions like the Northeast, where humidity and rain are a constant threat, wheat is often harvested at between 20 and 30 percent moisture and dried down in large mechanical driers. The driers can be brutal and inexact; some of the wheat may overheat, destroying the delicate wheat germ (a shame, since the natural oils in the germ are what imbue the grain with flavor); some may be damaged by condensation that forms inside the bin. The end result is usually serviceable, but not ideal for baking.

Some farmers dry their wheat by spraying their fields with glyphosate — though few will admit it. Glyphosate, the herbicide found in Roundup, was developed to kill weeds, not crops, but it is still employed as a desiccant to reduce dry-down time and ensure uniform ripening. The practice is alarming to many because the glyphosate is applied late, just before harvest (any later and it would be sprayed on our morning toast), and because last year, the World Health Organization’s International Agency for Research on Cancer classified the herbicide as “probably carcinogenic to humans.” Still, for these farmers, spraying is a better bet than leaving the wheat vulnerable on the stalk.

Klaas had no choice but to leave the wheat on the stalk. As an organic farmer, he couldn’t use a chemical to desiccate the wheat, and it’s highly unlikely the rabbi would have allowed it anyway. And mechanical drying, which he normally employs, was not permitted by the rabbi because of the threat of condensation and the use of an “open flame” — high heat that could potentially damage or denature the grain. (Some rabbis are less strict about these rules.)