古川養豚場’s Silk Sweet sweet potatoes, 3kg (grown in Chiba Prefecture, sold with soil on), are sold on Rakuten Ichiba as a single 3kg size. The product page states that the sales unit is 3kg, about 6 to 10 potatoes. In this article, we’ve organized the product page and publicly available reviews into five points: contents, storage method, ingredient labeling, suitability as a gift, and reviews. Items that could not be confirmed from the product page, such as the number of servings, a best-before date, and allergen labeling, are marked as not confirmed.
What We Confirmed
- Contents and serving size guide
- Storage method and shelf life
- Ingredients and allergen labeling
- Suitable as a gift?
- Trends in publicly available reviews
Basic Information
This table transcribes what is stated on the product page. However, the “not confirmed” labels and any notes we add are our own.
| Product Name | Sweet Potatoes, Silk Sweet, 3kg, Grown in Chiba Prefecture (古川養豚場)Source: Rakuten Ichiba product page. The product name shown on Rakuten’s page also includes terms such as 2026 new crop, 豚が育てた絹芋 (a silk potato raised by pigs), and baked sweet potato, but this article omits them |
|---|---|
| Name | Sweet potatoes [Silk Sweet] (with soil)Source: Rakuten Ichiba product page (viewed October 3, 2026) |
| Contents | 3kg. The sales unit is 3kg, about 6 to 10 potatoes. Sizes are shown as M, L, and LL by the shop’s own standard. We found no statement of how many servings it makes, so this is not confirmedSource: same as above |
| What Changes by Selection | There is no amount selection field; this product is a single 3kg size. The same shop’s 5kg and 7kg sizes appear as separate product pages. When ordering, there is an optional check box to receive a gift of seasonal vegetables, and the listing says what you receive is a surprise (viewed October 3, 2026. The contents and availability may change)Source: same as above |
| Storage Method | The listing advises opening the box after arrival to check the contents. It advises storing them in a place out of the sun and wind with a steady air temperature, and because they spoil at 10°C or below, to keep them in a heated living room or similar even at night in winterSource: same as above |
| Best-Before Date | No best-before or use-by date is shown, so this is not confirmed. As a guide from the shop, the listing says they keep for about 1 monthSource: same as above |
| Raw Material Origin | Sweet potatoes / Chiba Prefecture (Katori City). This is what the origin field of the product page statesSource: same as above |
| Place of Processing | Not confirmed (sold as sweet potatoes with soil on, and no place of processing was found) |
| State / How to Eat (Whether Heating Is Required) | These are sweet potatoes with soil on. The seller recommends them for baked sweet potatoes and states that they are done in about 50 to 60 minutes at 240°C in an oven or similar, and also states that a microwave is not OK. We found no statement on whether they can be eaten rawSource: same as above |
| Shipping | The carrier is shown as home delivery service (Japan Post) (viewed October 3, 2026). The estimated delivery date varies with the time of the order (at the time of viewing on October 3, 2026, an expected delivery date based on the order date and time was displayed). The temperature zone is not confirmedSource: same as above |
| Manufacturer | Not confirmed (no address for a manufacturer or seller was found in the product description. The shop name is 古川養豚場) |
| Shop | 古川養豚場 (Rakuten Ichiba) |
Prices are not listed because they change. Please check the latest price and stock at the link above.
Ingredients and Allergen Labeling
The product page lists the product as sweet potatoes [Silk Sweet] (with soil), with the origin given as Chiba Prefecture (Katori City). Within what we could check, no allergen labeling was found. This item is not confirmed. If allergens are a concern, please ask the shop before buying, or check the labeling on the product when it arrives.
Reference: Consumer Affairs Agency, Japan, “About Allergen Labeling” (accessed October 3, 2026)
As for cultivation, the shop’s listing describes them as sweet potatoes grown using plenty of high-quality compost from the pig farm (Source: Rakuten Ichiba product page, viewed October 3, 2026).
Five Things to Check Before Buying
| What to Check | For This Product | Basis |
|---|---|---|
| 1. Contents / serving size | 3kg (about 6 to 10 potatoes). No serving size is listed, so this is not confirmed | Rakuten Ichiba product page |
| 2. Storage method and shelf life | Store out of the sun and wind. Because they spoil at 10°C or below, the listing advises keeping them in a heated living room or similar in winter. The listing says they keep for about 1 month (no best-before date is shown, so this is not confirmed) | Rakuten Ichiba product page |
| 3. Ingredients and allergen labeling | Sweet potatoes [Silk Sweet] (with soil), from Chiba Prefecture (Katori City). No allergen labeling was found, so this is not confirmed | Rakuten Ichiba product page |
| 4. Suitable as a gift? | Noshi (a gift wrapping paper) is shown as not supported. No listing for gift wrapping or a message card was found, so this is not confirmed | Rakuten Ichiba product page |
| 5. Review trends | Rakuten Ichiba shows a rating of 4.89 / 5 (1,415 reviews). We read the first 60 in the standard sort order (posted October 2025 to October 2026, the most recent in October 2026) and a total of 18 filtered to ★1, ★2, and ★3 (posted January 2015 to November 2018), 78 in total. Many posts praise the sweetness, the moist texture, and the good appearance, and the posts that raised concerns were all from November 2018 or earlier. This is a trend within the reviews we read and may not represent the current condition of the product | Rakuten customer reviews (“Minna no Review”) (viewed October 3, 2026) |
Suitable as a Gift?
The Rakuten Ichiba product page shows noshi as not supported. We found no listing for gift wrapping, a message card, or wrapping, so we could not confirm them. The product is treated as not eligible for Rakuten Ichiba’s feature for sending a gift directly to the recipient (Social Gift) (viewed October 3, 2026). If you are considering it as a gift, checking the following points with the shop before buying will help avoid misunderstandings.
- Whether noshi and wrapping are supported (noshi is shown as not supported; wrapping is not mentioned on the product page)
- Whether it can be delivered directly to the recipient’s address (Rakuten’s feature for sending directly to the recipient is treated as not eligible)
- Whether the recipient can store them in a place out of the sun and wind. In winter, the listing advises keeping them in a heated living room or similar
Among the reviews we read, some posts said they used it as a gift or for a seasonal greeting. This is how those buyers used it, separate from the shop’s official gift support listing (Source: Rakuten customer reviews, viewed October 3, 2026).
What Public Reviews Say
Below is a summary of the Rakuten Ichiba product reviews, organized by topic. The rating figures are as of the time viewed and may change afterward.
| Site | Rating | Reviews | Date Viewed |
|---|---|---|---|
| Rakuten customer reviews (product page) | 4.89 / 5 | 1,415 reviews | October 3, 2026 |
Rating breakdown: ★5 1,285 / ★4 112 / ★3 12 / ★2 5 / ★1 1 (as shown by Rakuten Ichiba, viewed October 3, 2026). The rating and review count above are the values shown by Rakuten Ichiba. We read 78 of them, and their trend may not represent the current condition of the product.
Range read: the first 60 in the standard sort order (posted October 2025 to October 2026, the most recent in October 2026), plus 1 review at ★1 (January 2016), 5 at ★2 (January 2015 to December 2016), and 12 at ★3 (January 2015 to November 2018), 78 in total. All 18 reviews at ★3 or below were posted in November 2018 or earlier, and none were from the past 2 years. This is a trend within the reviews we read and may not represent the current condition of the product. The counts for each topic are approximate numbers counted by eye.
What Reviewers Praise
Sweetness
About 35 of the 60 in the standard sort order mentioned sweetness. These include posts saying they found it sweeter than the sweet potatoes bought at a supermarket. All were ★4 to ★5 posts, from October 2025 to October 2026.
Moist, smooth texture
About 20 of the 60 in the standard sort order mentioned finding it moist, sticky, or smooth. All were ★5 posts, from November 2025 to October 2026.
Appearance, size, and condition
About 26 of the 60 in the standard sort order mentioned that the potatoes were clean-looking, fine in size, and free of damage. These were ★4 to ★5 posts, from December 2025 to September 2026.
Taste as baked or steamed sweet potatoes
About 23 of the 60 in the standard sort order mentioned how they cooked it, saying it tasted good as a baked sweet potato (in a toaster, an air fryer, etc.) or a steamed sweet potato (in a rice cooker, etc.). About 10 of these were posts about steaming it.
Source: Rakuten customer reviews (“Minna no Review”) (viewed October 3, 2026)
What Reviewers Note
Rot, damage, and breakage
Of the 18 reviews at ★1, ★2, and ★3, 7 (1 at ★1, 2 at ★2, and 4 at ★3) mentioned that part of what arrived was rotten, damaged, or broken. All were posted between January 2015 and February 2018, and none are from the past 2 years.
How to check: the storage method is summarized in the “Storage Method” row of “Basic Information” in this article.
Mild or weak sweetness
Of the 18 reviews at ★1, ★2, and ★3, 6 mentioned finding the sweetness mild or weak. All were posted between January 2015 and February 2018, and none are from the past 2 years.
Large size, so baking takes time
Of the 12 reviews at ★3, 3 mentioned that each potato was large and took a long time to bake as a baked sweet potato. They were posted between January 2015 and January 2016, and none are from the past 2 years.
How to check: the baking method the shop gives for baked sweet potatoes is summarized in the “State / How to Eat (Whether Heating Is Required)” row of “Basic Information” in this article.
Source: Rakuten customer reviews (“Minna no Review”) (viewed October 3, 2026)
Who It Suits / Who Should Be Careful
Who It Suits
- You want to buy 3kg (about 6 to 10 potatoes) of sweet potatoes with soil on at once
- You want to eat them as baked sweet potatoes (the seller recommends them for baking)
- You can open the box on arrival to check the contents and store them out of the sun and wind
Who Should Be Careful
- You want to check the number of servings, the best-before date, and allergen labeling before choosing (none were found; not confirmed)
- Because they spoil at 10°C or below, you want to consider whether you can keep them in a heated living room or similar in winter
- You want to use it as a gift that assumes noshi and wrapping (noshi is shown as not supported)
- You care about the size of each potato (M, L, or LL by the shop’s standard) or the baking time
Prices, stock, shipping fees, and delivery dates are subject to change. This article’s information-as-of date is October 3, 2026. Please be sure to check the listing at the link before purchasing.
This article contains affiliate links (advertising). Editorial Policy
Summary
- The contents are a single 3kg size (about 6 to 10 potatoes). Store them out of the sun and wind; the listing says they keep for about 1 month (no best-before date is shown, so this is not confirmed)
- Many reviews praise the sweetness, the moist texture, and the good appearance. Comments about rot or mild sweetness were limited to old posts from November 2018 or earlier (within the 78 reviews we read; this may not represent the current condition of the product)
- The number of servings, allergen labeling, and gift wrapping could not be confirmed, and noshi was shown as not supported
Related Pages
This article organizes information published on various retail and review sites. Product details such as contents, storage method, and ingredients are subject to change. Please check the seller’s listing for the latest information.
Comments on taste or quality are summarized from third-party posts cited with their source, and are not Ochinity’s own evaluation. Our approach to writing articles is described in our Editorial Policy.
Information as of: October 3, 2026 / Sources: Rakuten Ichiba “古川養豚場” product page, Rakuten customer reviews (“Minna no Review”), Consumer Affairs Agency, Japan, “About Allergen Labeling”
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