A retained sample is a few finished units from each batch, kept back in their own packaging, labeled with the lot, and stored the way customers store the product, until the batch's shelf life has run out and a little longer. They're there for the day something is questioned: a customer says the jam tastes off, a shop says a jar separated, a buyer asks whether a lot met its specification. With a retained sample you can taste, test or show the same batch, instead of guessing from memory or a different batch. For most food and cosmetic makers it's good practice rather than a rule; dietary supplement makers are required to keep reserve samples of every lot they distribute (21 CFR 111.83). In the example below, a complaint about one pack of kūlolo is answered in an afternoon by tasting the retained pack from the same batch. Below is why to keep them, how many, how long, the log, and how they fit your stock records.
The short version
- Keep a few finished units from every batch, in their own packaging, labeled with the lot.
- Store them as customers will: shelf, fridge or freezer.
- Keep them until the shelf life has passed, plus a margin.
- Log what was kept, where, and when it can be thrown away.
- Count them out of stock as samples, so the books match the shelf.
- Use them when a complaint, a buyer's question or a shelf life check comes up.
- TaroStack records retained units as an adjustment with the reason "sample", by lot. More below.
Why keep them
| When | What the retained sample does |
|---|---|
| A customer complains | Taste or test the same batch; is it the batch or how it was kept? |
| A buyer questions a delivery | Show a unit from the lot, unopened |
| A supplier's ingredient is recalled | Test product from the batches that used it, if testing is needed |
| You're checking shelf life | See how real batches age, not only study samples |
| A recipe or supplier changed | Compare the new batch with the old, side by side |
How many, and how long
Keep enough to taste or test twice: two to four units for most products, more if a test needs a lot of product. Keep them until the best-by date has passed, plus a margin such as a month, so a complaint that arrives late still has a sample to answer it. Dietary supplements have a set rule: reserve samples of each lot distributed, held in the same container-closure system, identified by lot, and kept for one year past the shelf life date, or two years from the last distribution if there's no shelf life dating (21 CFR 111.83), and stored under the conditions on the label (21 CFR 111.465). This is general information, not legal advice.
A worked example
Windward Roots, the made-up taro business I use in these examples, keeps two packs from every batch of kūlolo in a marked box in the walk-in.
| Retained sample log | |
|---|---|
| Batch | KUL-1010-1 |
| Made | October 10 |
| Best by | October 17 |
| Units kept | 2 packs |
| Where | Walk-in, retained samples box, top shelf |
| Keep until | November 17, a month past best-by |
On October 16, Kailua Natural calls: a customer says a pack from KUL-1010-1 tasted sour. One retained pack is opened and tastes as it should, and the batch record shows its cook temperature was within the limit. With the shop's other packs of the same lot fine too, the likely cause is how that one pack was kept after it left the shop. The answer, and the replacement pack, go back the same afternoon, and the complaint is recorded with the lot; how is in customer complaint log.
Keeping the log, and the books, right
Every retained unit is a unit that won't be sold, so it should come off stock as a sample, with its lot, when it's set aside; otherwise the count will always be two packs short of the books. Throw retained samples away on the keep-until date, and record that too. Retained units are also a cost of the batch; a batch that makes 42 packs and keeps 2 sells 40. How a batch's yield and its samples are accounted for is in batch yield formula, and what makes a record like this log useful is in food business record keeping.
Where this stops working
A retained samples box works until nobody remembers what's in it. Packs without lot codes, a box that's never cleared, two packs set aside but still counted as stock, and on the day of a complaint, a search through the walk-in for a pack that might be from the right batch.
How TaroStack does it
TaroStack keeps retained units on the record, by lot, with everything else that happened to the batch.
Set aside as samples, by lot. Retained units come off stock as an adjustment with the reason "sample", from the batch's lot, so the books and the shelf agree and losses are reported by reason, item and site. Every movement is a permanent record of who, when and why.
The batch, findable from its code. Every batch goes into a lot with its code and best-by date, lot labels print with the code, and the batch record shows its ingredient lots and the checks recorded on it, like the cook temperature. A complaint about a lot leads straight to its batch record and every customer who got it.
And dates that remind you. Lots close to their date show in your alerts, so the retained samples for a batch whose shelf life has passed are easy to find and clear.
| The job | Samples box | In TaroStack |
|---|---|---|
| Two packs set aside | Still counted as stock | An adjustment, reason "sample", by lot |
| Which batch is this pack? | Whatever the label says, if it has one | The lot code, on a printed label |
| The batch's record | In a binder | The batch record, with its lots and checks |
| Who else got this lot? | Read the orders | One report, lot to customer |
Lots, lot labels, adjustments with reasons, batch records and recalls are on every plan, from $49 a month. The first 30 days are free, with no credit card. If you'd like a hand setting up, ask, and we'll do it with you.