Bulk Transport and Tankers

Bulk liquid arrives in a tanker. The tanker carried something else last week. Whether that is a problem turns out to depend on several things, and one of them is who owns your company — which surprises most people.

Why time is the first question

A vessel does not transfer its absorbed taste into cold liquid on contact. Transfer by soaking — kavush — requires twenty-four hours.

And here is the structural point: by the time twenty-four hours have passed, the vessel's absorbed taste has itself deteriorated, because it is no longer ben yomo. The two clocks run together, which is why the analysis is more forgiving than the bare facts suggest.

That does not settle it, because there is a separate rabbinic reluctance to use such a vessel deliberately in the first place. But it changes the shape of the problem from "contaminated" to "how do we justify this properly".

The vessel used in abundance

A further consideration applies specifically to large vessels in constant heavy use — the Rashba permits such a vessel even within the day, and the Shulchan Aruch and Rema follow him. In practice the accepted ruling is stricter, following the Shach and Taz.

For a vessel in abundant use that is also past the day, the later authorities divide: one position permits it outright, while a number of major authorities are strict.

What matters for you is that this is a live, argued question rather than a settled prohibition — which is why the answer depends on circumstances rather than being uniform.

Where washing comes in

Tankers are washed between loads, usually with caustic detergent at high temperature. That is not merely hygiene in this analysis.

A hot wash with harsh detergent can be regarded as introducing a spoiling agent — and arguably as something closer to a proper purging. Either way it strengthens the position considerably, which is why wash records are worth keeping and producing.

Why ownership changes the answer

This is the part that catches people, and it is not arbitrary.

For a Jewish-owned company, or one with Jewish partners, the leniencies above are not relied on. A proper purging of the tanker is required.

For a non-Jewish-owned company, there is room to rely on the more permissive position. Rav Moshe Feinstein held that for such a company it is permitted as a matter of strict law — while adding that it is unseemly to grant a certification resting on that alone, which is why the practice is to look for additional grounds.

And the relevant company is the one producing the kosher food, not the haulier. A non-Jewish trucking firm does not help if your own plant is the one in question.

One further gradation: where the Jewish purchaser has no say at all in how the goods reach him, and both the seller and the haulier are non-Jewish, there is more room than where he controls the transport arrangements.

What this means practically

• Dedicated tankers are the clean answer where volume justifies them.
• Previous-load documentation is worth demanding as a matter of course, and most bulk hauliers can provide it.
• Wash certificates matter more than people assume — keep them.
• Kashering a tanker is possible; the method depends on the tanker.
• Tell your certifier who owns what. It genuinely changes the analysis, and it is not a question anyone will think to ask you.

See also shared equipment and what transfers.