Keep a correction trail when editing a scanned food label
A compact before-and-after record makes manual transcription corrections explainable, reversible and easy to propagate.
A manual correction should explain what changed and why. Editing a number in place without preserving its source makes it difficult to distinguish a verified repair from an unsupported guess. Use a small correction log alongside the current working record.
Capture the original error
Before editing, save the extracted text or screenshot. Assign the record a stable identifier and identify the affected field precisely: sodium amount in the per-serving column, for example. Include its unit and serving basis so the change cannot be confused with a conversion.
The FDA guide to using a nutrition label provides the label-reading background. The log described here is an editorial recordkeeping method; it is not an FDA-required personal template or a claim about any scanner's accuracy.
Write a complete correction entry
Use six fields: record identifier, field name, old value, new value, evidence and correction date. Add who made the change when several people maintain the notes. The evidence should identify a particular photograph or document section, not merely say checked online.
In a fictional example, a scan reads fiber 8 g per 40 g, while a clear second photograph shows 3 g. A useful entry reads: fiber amount; 8 g to 3 g; package photo second-capture, fiber row; decimal and unit checked; corrected by the recorder on the stated date.
Update the dependent calculations
The old per-100-g result was 8 ÷ 40 × 100 = 20 g. The corrected result is 3 ÷ 40 × 100 = 7.5 g. Save the new result with a link to the correction entry. If the old value also appeared in a custom-portion calculation or shared comparison, list those outputs and update them too.
Keep conversions separate from corrections. Changing 300 mg to 0.3 g can preserve the same quantity; changing 300 mg to 30 mg does not. Your log should reveal whether the underlying transcription changed or only its display unit.
If you later discover that the second photograph belonged to another flavor, reverse the correction using the saved history and mark the field unresolved. A reversible process is useful precisely because manual checks can also be wrong. The current record should show the latest supported value, while the log retains the path by which you reached it.