In any winery, the volume of wine that ends up in the bottle is always less than the volume of juice that went into the ferment. Losses are inherent to winemaking. What matters operationally is whether those losses are measured, understood, and managed — or whether they accumulate silently until year-end reconciliation reveals a gap that nobody can explain.
For New Zealand wineries — particularly those exporting and operating under MPI's Wine Act documentation requirements — loss tracking is not just a financial exercise. It is a compliance imperative.
Where Wine Is Lost in New Zealand Cellars
New Zealand's wine industry is characterised by a high proportion of cool-climate, aromatic white wine production. This shapes the specific loss profile of a typical New Zealand winery.
Press house losses. Pressing whole-bunch grapes — the standard approach for premium Marlborough Sauvignon Blanc — generates gross lees that are typically settled and racked before fermentation. The solids and fine lees from juice settling contain significant residual juice. Well-run operations can recover 85–92% of the theoretical juice volume from whole-bunch pressing; less careful operations see yields at the lower end of this range.
Fermentation losses. During active fermentation, CO₂ carries aromatic compounds and small volumes of ethanol out of the tank. In cool-climate fermentation (10–15°C for premium Sauvignon Blanc), these losses are relatively modest compared to warm fermentations, but they are real. Open-top red wine fermenters — used for Pinot Noir in Central Otago, Martinborough, and Nelson — also lose volume during pump-overs and punch-downs.
Lees racking. After fermentation, settling wine off gross lees and fine lees removes a significant volume fraction. For white wines, the total lees loss across multiple rackings may be 3–8% of the fermented volume. For barrel-fermented Chardonnay, individual barrel geometry means some barrels give up less lees than others.
Barrel evaporation. New Zealand's relatively humid, mild winery environments — particularly on the South Island — tend to produce lower evaporation rates than warmer wine regions globally. A well-maintained barrel cellar in Marlborough or Central Otago with humidity in the 70–80% range should see annual evaporation rates of 2–4% per barrel. Dryer or warmer conditions push this higher.
Transfer and filtration losses. Line volumes, pump priming, filter media absorption, and hose rinsing all contribute small but cumulative losses. For a winery doing multiple rackings, transfers, and filtration steps per batch, these aggregate losses can reach 1–3% of the batch.
Blending and sampling. Formal trial blends, quality tastings, and the wine sent out for export analysis and certifications all represent small, legitimate losses that should be recorded.
MPI and Wine Act Documentation Requirements
The Wine Act 2003, administered by MPI (Ministry for Primary Industries), requires that New Zealand wine producers maintain adequate records of wine production and sales. While the Act does not specify the precise format of these records, audits under the Act typically look for:
- Grape intake records (grower, variety, region, weight)
- Winemaking records linking intake to production batches
- Volume of wine produced per batch
- Volume of wine sold, exported, or destroyed
- Current cellar inventory
When volumes do not balance — when the intake weight and calculated juice yield do not reconcile with production and inventory records — the discrepancy needs to be explainable. Documented, categorised losses (racking losses, evaporation, filtration, etc.) provide that explanation.
For export wines, the export permit process requires accurate volume declarations. Producers whose internal records do not support the declared volumes face delays and potential compliance issues with MPI's export certification.
Benchmarks for New Zealand Wine Production
General benchmarks for volume losses in well-managed New Zealand wineries:
- Juice yield from whole-bunch pressing (white varieties): 650–720 L per tonne, depending on variety, press efficiency, and extraction target.
- Fermentation and settling losses (whites): 3–6% of juice volume.
- Barrel evaporation (annual): 2–4% per barrel in good cellar conditions.
- Total production loss, tank-fermented whites (Sauvignon Blanc): 5–10% from juice to finished wine.
- Total production loss, barrel-aged reds (Pinot Noir): 12–20% over an 18-month production cycle including all racking, blending, and filtration losses.
Operations consistently running at the high end of these ranges should investigate whether specific loss sources are above normal. Operations significantly above these benchmarks have a genuine financial problem.
Tracking Losses in Practice
The foundation of loss management is a real-time cellar inventory — knowing the current volume in every vessel, updated each time a transfer, racking, or other volume-affecting event occurs.
Vessel volume tracking: For tanks, this means maintaining accurate capacity calibrations (vessel dip tables or electronic level sensors) and recording fills and transfers at the time they occur. For barrel programs, it means regular barrel inventories — typically a monthly or quarterly physical check of bung levels and barrel condition.
Transfer documentation: Every pump transfer should be recorded with source vessel, destination vessel, volume transferred, and any volume lost (hose, pump, line). This creates a complete movement history for each lot of wine.
Loss categorisation: Rather than recording a generic "loss" entry, categorise losses by type — press lees, racking lees, filtration, evaporation, sampling, breakage. This breakdown makes it possible to identify whether a specific loss category is running high.
Reconciliation schedule: At a minimum, conduct a full cellar reconciliation at the end of vintage and at the end of the financial year. Better operations do it quarterly. The reconciliation compares intake volumes (converted from grape weight to juice volume) against production records, current inventory, dispatched volumes, and documented losses. The balance should be close to zero.
Reducing Losses Without Compromising Quality
Loss reduction should always be evaluated against quality impact. Some losses are worth incurring — for example, discarding the most turbid press fraction rather than incorporating it into premium wine.
That said, several loss-reduction strategies reliably improve efficiency without compromising wine quality:
Press efficiency: Modern pneumatic presses — the standard in New Zealand — are more efficient than older screw or basket presses. Press program optimisation (pressure ramp rates, number of press cycles) can improve yield by 30–50 L per tonne without quality impact.
Cellar humidity management: Investing in barrel cellar humidity control reduces evaporation losses and pays back in wine volume retained. Even modest humidity improvements (from 60% to 75%) make a measurable difference over a barrel program's lifetime.
Lees management: Allowing lees to compact fully before racking — through extended settling or centrifugation — reduces the volume discarded with each racking. For high-value lots, lees recovery using a lees filter or centrifuge can reclaim significant additional volume.
Transfer volume recovery: Designing hose runs and pump positions to minimise dead-volume in the transfer system reduces the wine left in lines after each transfer. Using nitrogen or wine to flush hoses before rinsing with water recovers meaningful volume in high-frequency transfer operations.
Integrating Loss Tracking with Winery Management Systems
Manual loss tracking — in notebooks or spreadsheets — is manageable at small scale. As the number of batches, racking events, and transfer movements grows, the manual tracking burden increases and the risk of errors rises.
Winery management platforms that record all vessel movements as structured data automatically calculate losses as the difference between source and destination volumes at each transfer. Over a vintage, these recorded losses by category give a clear picture of where wine is going and whether any category is running above the expected range.
Cepaos, for instance, links vessel movements directly to lot records, so that every litre transferred or lost is traceable back to its origin batch — exactly the kind of documentation that MPI and export certification processes require.
For New Zealand wineries competing in premium export markets, where the expectation of supply chain transparency is rising, this kind of integrated volume accountability is rapidly becoming a baseline requirement rather than a competitive advantage.