Should New Raw-Material Deliveries Be Kept Separate From Existing Approved Inventory Until Basic QC Is Completed?

Yes, and physically, not just on paper

Keep every new delivery on its own shelf, in its own container, with a status tag, until basic QC is done and the release is signed. A note in a log that says "new lot, not yet checked" does not stop a busy hand from grabbing the nearest bag. Physical separation does.

The reason is not tidiness. Incoming QC compares a new lot against a known reference and decides whether it may enter production. If new material is mixed into approved stock before that decision, three things break at once: you can no longer test the new lot on its own, your retained sample no longer represents what is in the bin, and any fault that appears later cannot be traced to either lot. You have not skipped a check; you have made the check impossible.

Worked example: what one top-up does to traceability

Picture two ordinary shortcuts on a delivery day. They feel efficient. The arithmetic shows why they are not.

The wax bin

Your approved wax bin holds 4 kg of the old lot. A new 10 kg bag arrives and, to save space, it goes straight into the same bin. Every scoop is now roughly 4 ÷ 14 = 29% old lot and 71% new lot, and the ratio changes as you go down the bin because the new wax sits on top. If candles from next week show more frosting, there is no clean way to say which lot caused it. Your 100 g retain from the old lot is still on the shelf, but it no longer represents what you are pouring.

The oil bottle

You have 300 g left of approved Lavender and a new 1 kg bottle arrives. Topping up the old bottle gives 1,300 g of mixed oil. At 16 g per 200 g candle at 8%, that is 1,300 ÷ 16 = 81 candles, rounded down, carrying a blend of two lots in an unknown ratio. The material at risk, at the listed 1 kg price, is ₹5,221.00 for the new bottle plus 300 g at ₹5,221.00 ÷ 1,000 = ₹5.221 per gram, which is ₹1,566.30, making ₹6,787.30 of oil that can no longer be qualified cleanly.

Deliberate blending of two approved lots can be a legitimate production decision, made after both have passed and recorded on the batch sheet. What defeats QC is mixing before the new lot has been judged at all.

A shelf layout that works in a small studio

You do not need a warehouse. You need four clearly different places and a rule about which direction material may move between them. A single steel shelving unit, a few lidded crates and some coloured tape are enough for most home studios.

Put the quarantine zone further from the pouring bench than the approved zone. Distance is a surprisingly effective control: nobody walks past the approved shelf to take a bag from quarantine unless they mean to. Keep the rejected box closed and below eye level so that it never looks like spare stock.

Labels and containers that make the status obvious

A status tag should be readable from across the room and hard to lose. Coloured card tags on string, tied through a bag clip or around a bottle neck, work better than sticky notes that fall off. Each tag carries the receipt code, the date received and the status; the approved tag adds the date of release and initials.

Where the supplier's pack carries no printed lot number, the receipt code you write on it becomes its identity. Use a permanent marker on the bag or bottle itself as well as the tag, so that if the tag is lost the material is still traceable to its invoice and delivery date.

Releasing without undoing the separation

Release is the moment separation is most easily lost. When a new wax lot is approved, do not pour it into the bin that still holds the tail of the old lot. Finish the old lot first where you can, or run the old and new lots as separate production batches recorded against their own receipt codes. When you do open the new lot, the batch sheet should show which receipt code went into which candles from that day on.

The same applies to oils. Keep the old approved bottle until it is empty, then start the new bottle as a fresh line on the batch sheet. If you need both at once, pour from them into separate labelled candles rather than combining them.

Rejected material deserves the same discipline. Do not quietly move a rejected bag to the approved shelf because the supplier has not replied yet, and do not use it for a production run you consider low-stakes. If you and the supplier later agree it can be used for a limited purpose, write that condition on a yellow tag and treat it as a conditional release with its own record.

Finally, look at the shelves once a week with one question: is anything on the approved shelf without a green tag, or anything in production that came from the quarantine shelf? If the answer is ever yes, the layout needs changing, not a stern word. Controls that rely on memory fail on busy days; controls built into where things physically sit keep working.

Where this page fits

CSI already has guides that cover parts of this question. This page covers the goods-in check for the question above; these go deeper on the rest:

Three things to buy for this job

Frequently asked questions