Yoshon and Chodosh

Yoshon means "old" — grain that took root before a given year's Pesach. Grain taking root after it is chodosh, "new", and may not be eaten until the following Pesach has passed.

Five grains, and only five

The rule covers wheat, barley, oats, rye and spelt. Rice, corn, buckwheat, millet, quinoa and everything else are outside it entirely and never raise a chodosh question.

The cut-off is the taking of root, not the harvest. Grain that took root before the second day of Pesach becomes permitted on that day. Grain rooting later carries the restriction from its harvest until the following Pesach — roughly a seven-month window.

Whether it applies today, outside Israel

Whether the prohibition applies outside the Land of Israel, and to grain grown by a non-Jew, is a long-standing dispute. The Rema records the lenient view as the prevailing practice in the diaspora, and much of the Jewish world relies on it. A significant and growing community does not, and keeps yoshon year-round.

Both are established positions. Which you follow is your community's practice.

Why most flour is already yoshon

This surprises people who assume keeping yoshon means constant vigilance. The agricultural calendar does much of the work.

Winter crops are planted in autumn, sit through the winter — and so through Pesach — and are harvested in early summer. They are yoshon by the time they are milled. Spring crops are planted after Pesach and harvested at summer's end, making them chodosh until the following Pesach.

In the United States that splits cleanly. Winter wheat is always yoshon. US-grown rye and spelt are winter crops and always yoshon — though much rye and spelt is imported from Canada, where they are usually chodosh. Spring wheat, oats and barley are the exposure.

The two wheats are not interchangeable, and that turns out to matter. Winter wheat is low in protein and makes crumbly dough, so it goes into cookies, crackers, pretzels, cakes and matzah. Spring wheat is high in gluten and makes strong dough, so it goes into breads, rolls, bagels, challah and pasta. Cake and cookie flour is therefore yoshon year-round; bread and pasta flour is where the question lives.

Malt, which nobody thinks about

If a yoshon practice fails, malt is usually why. Barley malt is used two entirely different ways.

A fraction of a percent of malted barley flour is added to almost all bakery and grocery flour to help dough rise — cake and cookie flour being the exception. Some poskim hold this quantity is nullified in the flour; others do not, which means that under the stricter view even pure winter wheat flour can become a question once new-crop malt enters it.

The second use is substantial: malt added for colour and flavour, in pretzels, many cereals, some candies, beer and several spirits. There is far less room for leniency there, and it is where a product quietly acquires a problem through an ingredient nobody was considering.

Because of processing lead times, malt from the new barley crop generally does not ship before mid-December — which gives a usable marker for anything produced before then.

One oddity worth knowing

A minor category, soft spring wheat, is grown in the western states and used near where it is grown. The consequence is that the identical product can be yoshon or chodosh depending on where it was packed — the same cookie may be yoshon from one plant and chodosh from another.

Whether your household keeps yoshon, and what to buy if so, is a question for your rav.