A practical, step-by-step receiving inspection method to verify glazing percentage on IQF vegetables using low-cost tools. Includes sampling, calculations, tolerances, and documentation tips you can use today.
If you buy IQF vegetables, you already know glaze can be the difference between a fair deal and a short-weight headache. And yet, inspectors using the same lot often report different glaze percentages. Why? Because small differences in water temperature, spray time, and drainage add up. After years testing Indonesian IQF veggies at receiving, here’s the simple, repeatable way we use and recommend to customers.
What glazing is and why it matters
Protective glaze is a thin ice layer applied after IQF to protect the surface from dehydration and oxidation. It stabilizes color and texture during storage and transit. The catch is that excessive glaze inflates gross weight without adding edible product. Too little glaze invites freezer burn and arrival complaints.
Most contracts for vegetables set a target range. In our experience, retail packs often run 6–12% glaze and foodservice 8–15%, but always work to the spec on your PO. The best inspection method is the one your team can repeat exactly week after week. Consistency beats complexity.
The simplest on-arrival method we trust
We rely on a controlled cold-water spray deglaze with standardized timing and drainage. It’s fast, low-cost, and works across product types, from Premium Frozen Sweet Corn and Frozen Mixed Vegetables to Premium Frozen Okra, Frozen Paprika (Bell Peppers) - Red, Yellow, Green & Mixed, and Premium Frozen Edamame.
Equipment you actually need
- Calibrated digital scale (readability 1 g for consumer packs, 5 g for bulk)
- Food-safe perforated colander/sieve that fits over a drain tray
- Spray head with consistent flow (not a power jet). A simple shower head works.
- Clean, potable chilled water at 2–4°C
- Timer or stopwatch
- Infrared or probe thermometer for water and product surface
- Absorbent towels or lint-free wipes
- Data sheet or app for recording. Camera for photos.
Pro tip: Pre-chill your colander, tray, and scale pan in a chiller. I’ve found this alone reduces result variance by 1–2 percentage points.
Step-by-step deglazing SOP (receiving)
This is written for consumer or foodservice packs up to 2.5 kg. For bulk cartons, test a representative inner bag or sub-sample.
- Condition the sample
- Keep cases at -18°C or colder. Pull samples only when you’re ready to test.
- Record product, lot, pack weight, target glaze from spec, and carton temp.
- Gross weigh (glazed)
- Remove the closed pack from the carton, wipe any frost from the bag exterior, and weigh immediately. Record Gross Glazed Weight.
- Transfer to colander
- Open the bag and pour the frozen contents into the pre-chilled perforated colander over a drain tray. Avoid product falling from height. Record the Empty Bag Weight if you want a pack-weight audit.
- Cold-water spray deglaze
- Spray with 2–4°C potable water from 20–30 cm above the product using a gentle shower pattern. Aim for all surfaces, not a single spot.
- Spray in short bursts of 10–15 seconds, then pause 10 seconds to drain. Repeat until surface ice crystals are gone and pieces look matte, not glossy.
- Typical total spray time: 20–45 seconds for most IQF vegetables. Dense items like okra slices can take a bit longer.
- Drain and standardize surface moisture
- Let drain 60 seconds in the colander. Gently shake twice to release trapped water. Do not squeeze or press.
- Quickly blot the outside bottom of the colander with a towel so no water drips onto the scale.
- Net weigh (deglazed)
- Weigh the deglazed product in the colander on the scale. Record Deglazed Net Weight.
- Confirm stability: wait 30 seconds and re-weigh. If change >0.3% of sample weight, drain 30 seconds more and recheck.
- Temperatures and photos
- Record water temperature and product surface temperature right after deglaze. Take one clear photo of the setup and the final deglazed state.
- Repeat for your sample set
Calculation you’ll actually use
- Glaze weight (g) = Gross Glazed Weight − Deglazed Net Weight
- Glaze percentage (%) = Glaze weight ÷ Gross Glazed Weight × 100
- True product net (%) = Deglazed Net Weight ÷ Gross Glazed Weight × 100
To check short-weight against the label, compare Deglazed Net Weight to the Labeled Net Weight. Average across your sample set before concluding.
How many packs should I sample?
We keep it practical at receiving while still statistically defensible.
- Container or full-truck deliveries: 8–12 packs is a good baseline. Pull from at least 4 different pallets and 2 cases per pallet.
- Small LTL shipments: 4–6 packs across different cases.
- If the first 4 samples are out-of-spec in the same direction, expand the sample size before deciding claims.
If you use Z1.4 or MIL-STD tables, AQL 2.5 on consumer packs typically lands you near 13–20 samples depending on lot size. But most buyers don’t have time for that at receiving, and a stratified 8–12 sample set gives reliable direction.
What tolerance should I allow before raising a claim?
Glaze tolerance is a contract item. In buyer–supplier relationships we manage, ±2 percentage points from the target is a fair operating window. Examples:
- Spec 10% glaze. Acceptable 8–12% average across your sample set.
- Above 12% suggests overglaze and potential short-weight. Below 8% risks dehydration and arrival defects later.
For net weight, most markets expect the average to meet or exceed 100% of the labeled net. Individual pack variability happens, but a low average triggers a short-weight discussion.
Why do different inspectors get different glaze results?
Three avoidable reasons show up again and again:
- Water too warm or inconsistent. Spraying with 10–15°C water melts more than glaze. Use 2–4°C and record it.
- Over-spraying. The goal is to remove the shell of glaze, not thaw the vegetable. Keep total spray time as short as possible and use pauses to drain.
- Poor drainage control. Trapped water in a non-perforated pan or rushed transfers add weight. Always use a perforated insert with a drain tray and standardize a 60-second drain.
We also see unchilled colanders and scale pans causing micro-thaw that skews results. Pre-chill the hardware and you’ll get tighter repeatability. This simple step is the least obvious, most impactful fix we recommend.
What water temperature removes glaze without thawing the product?
Use 2–4°C. Colder water reduces heat transfer into the product core and focuses energy on the exposed glaze. You can maintain this easily with a small ice bath feeding your spray line or by keeping a chilled jug in a reach-in chiller.
Is there a widely accepted standard method?
There isn’t a single global standard specific to vegetables that everyone follows. Most buyers adapt a cold-water spray-and-drain method similar to approaches used in seafood glazing checks. What matters is that your method is written, repeatable, and shared with suppliers ahead of time. When our customers align with our SOP, dispute rates drop dramatically.
Common mistakes to avoid
- Using running tap water at ambient temperature. It strips glaze and starts thawing.
- Leaving product sitting in water. You’re adding water weight, not removing ice.
- Skipping the stability check. If your weight keeps dropping, you’re still draining.
- Mixing product types in one test. Okra and corn behave differently. Keep tests product-specific.
- Judging from one or two packs. Random variability is real. Use a stratified sample.
Documenting results that stand up in a claim
If you ever need to escalate, clean records win the day.
- Record everything: lot, pack size, target glaze, water temp, product temp, all weights, spray time, drain time.
- Photos: pack label, your scale display for gross and net, and the deglazed product in the colander.
- A short 10–15 second video helps when results are borderline.
- Average the sample set and show both glaze% and net vs label. Suppliers respond better to grouped data.
If you’d like a one-page SOP and a calculator sheet we use with customers, need help adapting tolerances to your labels, or want us to sanity-check your first inspection run, just Contact us on whatsapp. We’re happy to share templates and talk through edge cases.
2026 trend watch: what we’re seeing
- Buyers are writing glaze targets as ranges with explicit ± tolerances instead of “up to X%.” It reduces gray areas.
- More teams are capturing water and product temperatures in the photos. This simple practice has cut back-and-forth emails by days.
- Video-based inspections are becoming normal. A 30-second clip of the spray-and-drain sequence removes doubt.
Quick answers to the questions we get most
What’s the simplest way to measure glaze at receiving?
Use the cold-water spray method above. Weigh sealed pack. Pour to a perforated colander. Spray with 2–4°C water in 10–15 second bursts. Drain 60 seconds. Weigh. Calculate glaze% from the two weights.
How much variance should I allow before a claim?
If your contract doesn’t say, we suggest ±2 percentage points on glaze. For net weight, hold the average at or above 100% of label.
How many packs do I need to sample?
Aim for 8–12 packs from multiple pallets for full loads. For small shipments, 4–6.
Why do inspectors disagree on the same lot?
They’re using different water temperatures, spray times, or drainage periods. Standardize those three and disagreement shrinks fast.
How do I calculate glaze percentage accurately?
Glaze% = (Gross Glazed − Deglazed Net) ÷ Gross Glazed × 100. Always average across your sample set.
What about dehydration loss vs glaze at arrival?
Low glaze increases dehydration during transit. If you see matte, whitish surfaces or tough texture on arrival and your measured glaze is below spec, you likely have a dehydration issue. Photographs and texture notes help make that case.
When this advice applies (and when it doesn’t)
Use this method for true IQF vegetables and blends. It doesn’t apply to blocks, sauce-coated items, or pre-fried products with batter, where water interacts differently with the surface. For products like Premium Frozen Potatoes that are par-fried, adapt the spray time and be extra cautious with temperature to avoid surface softening.
Takeaway you can use today
- Lock water at 2–4°C. Standardize spray in 10–15 second bursts and a 60-second drain.
- Pre-chill your colander and scale pan to cut variance by up to 2 points.
- Sample 8–12 packs across pallets. Average results. Use ±2 percentage points as a working glaze tolerance if your contract is silent.
Want help tailoring this SOP to your receiving setup or Indonesian supply lane? Send your current method and target specs and we’ll mark them up with practical tweaks. Or if you’re reviewing a new line of IQF vegetables, browse what we produce and export year-round. View our products.