What is kurobuta? Japan's "black pork" labelling rule and its 3 Berkshire brands

Only purebred Berkshire may be labelled kurobuta

The ministry's guideline on labelling wagyu and other distinctive meats says only meat from purebred Berkshire pigs may be labelled kurobuta. The meat industry association's handbook adds that this applies to Japanese and imported pork alike, and that labelling non-Berkshire pork in a way that could be mistaken for kurobuta is misleading labelling.

Sources: [W001] [W002]

The origin must be shown with it

So that imported pork is not mistaken for Japanese kurobuta, the guideline says the origin must always be shown wherever "kurobuta" appears, including on optional stickers. Its examples include "Kagoshima kurobuta", "kurobuta from ○○ Prefecture", "US kurobuta" and "Canadian kurobuta", and it says Japanese kurobuta should preferably name its prefecture or locality.

Sources: [W001]

Crossbreds may say "Berkshire", not kurobuta

According to the handbook, crossbreds of Berkshire and another breed may be labelled as Berkshire crosses using the word "Berkshire", but not "kurobuta". Its examples of what is not allowed include phrases such as "with kurobuta blood" and "made with Berkshire (kurobuta)", and names that use the character for "black" in a way that suggests kurobuta.

Sources: [W002]

Kurobuta brands in this guide

These brands require purebred Berkshire. Their other conditions differ from brand to brand.

Sainokuni Kurobuta Pork — Saitama

Breed

Berkshire Purebred Berkshire of British lineage

Feed

Finished on Sainokuni Kurobuta fattening feed with grains such as barley, sweet potato and domestic feed rice

Okayama Kurobuta Pork — Okayama

Breed

Berkshire Purebred Berkshire

Where it must be raised

As a rule, fattened on properly managed farms in Okayama Prefecture

Feed

A dedicated feed based on grains, with plant-only protein sources

Grading

Graded by a Japan Meat Grading Association grader (no minimum grade is set)

Kagoshima Kurobuta — Kagoshima

Breed

Berkshire All Berkshire (American Berkshire excluded), and not kept together with other breeds

Age at shipment

Shipped at roughly 230 to 270 days of age (the council lists this as one of its production standards)

Feed

In the late fattening stage, feed containing 10–20% sweet potato for at least 60 days

Other brands that mention Berkshire

These brands do not use "kurobuta" in their names, and their breed conditions do not say purebred Berkshire. The breed descriptions are as stated in their sources.

• TOKYO X: The synthetic line Tokyo X, developed from Beijing Black, Berkshire and Duroc. Breeding stock is distributed by the Ome Livestock Center of the Tokyo Development Foundation for Agriculture, Forestry and Fisheries
• Koshu Fujizakura Pork: Pigs from sows carrying the Fujizakura line (a Landrace line developed by the Yamanashi Livestock Experiment Station, now the Yamanashi Livestock and Dairy Technology Center) mated with boars of the synthetic Fujizakura DB line, completed by the same station in 2012 after seven years (Fujizakura DB is a synthetic line of Berkshire and Duroc)
• Olive Yumebuta Pork: Sanuki Yumebuta, a Kagawa brand pig developed from Berkshire imported from Britain

How we counted

"Require purebred Berkshire" means brands whose breed in this guide is Berkshire. Limits such as Kagoshima Kurobuta's "American Berkshire excluded" are given as the source states them. "Mention Berkshire" means the word Berkshire appears in the description of the breed condition.

Sources

Sources are in Japanese

1. [W001] 和牛等特色ある食肉の表示に関するガイドライン（平成19年3月26日 18生畜第2676号 農林水産省生産局長通知） — Ministry of Agriculture, Forestry and Fisheries ・ Accessed 2026-10-12
2. [W002] お肉の表示ハンドブック2025（和牛の表示 23〜25ページ、ガイドライン全文 207〜209ページ） — All Japan Meat Industry Cooperative Association ・ Accessed 2026-10-12

We read the guideline (W001) as reproduced in full on pages 207–209 of the handbook (W002). The handbook explains kurobuta labelling on pages 26–27.