Managing extreme seasonal flow variations, pomace and lees handling, and high-strength organic effluents from wine and cider production.
Winery and cidery effluent is highly seasonal and acidic, with organic loads that spike dramatically during harvest, pressing and tank-cleaning periods. Strong sugars, ethanol, tartrates and suspended solids drive COD well above municipal limits, while low pH and nutrient imbalance complicate biological treatment. Reynolds & Bauhm design buffered, robust systems — equalisation, pH correction and biological treatment — that absorb the vintage peak without upset. The result is reliable discharge compliance and water-reuse opportunity across the whole production calendar, not just the quiet months.
Winery and cidery wastewater is defined by one overriding characteristic: extreme seasonal variation. During the crush and harvest period, flows can surge 10 to 50 times above off-season averages, driven by grape pressing, juice extraction, and intensive cleaning operations. This concentrated window – typically 2 to 6 weeks – overwhelms conventional treatment systems not engineered for such hydraulic and organic shock loads.
Pomace and lees represent the primary solid waste streams. Grape pomace retains significantly higher moisture than brewery spent grain, typically 82–85% moisture content, making mechanical dewatering more challenging. Lees – the sediment of yeast, tartarates, and colloidal matter – are rich in proteins and polyphenols, which complicate polymer selection for dissolved air flotation (DAF) and can inhibit advanced biological treatment if not managed correctly.
Barrel washdown introduces additional chemical complexity: tartaric acid deposits, sulphur dioxide (SO2) residues used as antimicrobial agents, and oak tannins leached from new or refurbished casks. SO2 concentrations can reach 50–500 mg/L during peak washdown periods, requiring dedicated stripping or neutralisation to protect downstream biology and meet discharge limits below 1 mg/L.
Stuck fermentation wastewater – where fermentation halts prematurely – presents a uniquely difficult effluent: high residual sugar, extremely low pH (often below 3.5), and elevated SO2 levels. Without targeted pre-treatment, these streams can crash pH and overload biological stages, making flow segregation and dedicated equalisation essential design features.
Typical winery and cidery wastewater parameters by season, with treatment targets for compliant discharge.
| Parameter | Crush Season | Off-Season | Treatment Target |
|---|---|---|---|
| BOD | 3,000 – 8,000 mg/L | 500 – 1,500 mg/L | <20 mg/L |
| COD | 5,000 – 15,000 mg/L | 1,000 – 3,000 mg/L | <50 mg/L |
| TSS | 1,000 – 3,000 mg/L | 200 – 500 mg/L | <15 mg/L |
| pH | 3.0 – 5.5 | 5.0 – 7.0 | 6.5 – 8.5 |
| SO2 | 50 – 500 mg/L | 10 – 50 mg/L | <1 mg/L |
| Polyphenols | 100 – 800 mg/L | 20 – 100 mg/L | <10 mg/L |
A six-stage approach engineered for seasonal surge, pomace solids, and polyphenol-rich effluents.
Rotary drum or screw screens remove grape stems, skins, seeds, and apple pomace to protect downstream equipment and recover solids for dewatering.
Tanks sized for peak harvest flows (12–24 hour HRT at maximum daily volume) balance seasonal surges and stabilise influent quality before biological stages.
Automatic alkali dosing raises pH to 6.5–7.5. Aeration or chemical oxidation strips residual SO2 to <1 mg/L, protecting biomass and meeting consent.
Dissolved air flotation with polyphenol-tolerant polymers removes yeast cells, colloidal tannins, and fine suspended solids. Achieves >85% TSS and >60% polyphenol removal.
MBBR or compact SBR degrades residual sugars, organic acids, and soluble organics. Designed for low off-season loads with capacity for crush-season peaks.
Final clarification, UV disinfection where required, and pH correction before discharge to sewer or watercourse. Fully automated with SCADA monitoring.
Equalisation tanks must be sized for the crush peak, not the annual average. Typical design: 12–24 hour hydraulic retention time (HRT) at the maximum daily flow during harvest.
Peak flow = 400 m³/day → EQ volume @ 18 hr HRT = 300 m³
Peak flow = 1,000 m³/day → EQ volume @ 18 hr HRT = 750 m³
For wineries with highly concentrated 2-week crushes, a 24-hour HRT provides additional buffering against weekend loading spikes and equipment downtime.
Recover value from winery and cidery by-products while minimising disposal requirements.
Screw presses achieve 18–22% dry solids (DS) from grape pomace despite its high initial moisture. Low-energy operation with continuous discharge of dewatered cake suitable for composting or distillation.
Belt presses are preferred for apple pomace, reaching 20–25% DS due to the firmer cell structure. Gentle squeezing preserves pectin content for potential recovery in food-grade applications.
Gravity thickening of lees in dedicated cone-bottom tanks achieves 3–5% solids before dewatering. Supernatant is returned to the equalisation tank; thickened lees feed the press or decanter.
Winery lees and pomace retain valuable polyphenols including resveratrol, tannins, and anthocyanins. Selective solvent extraction or membrane concentration can recover these for nutraceutical or cosmetic markets.
Dewatered pomace at 20% DS is ideal for aerobic composting (C/N ratio ~20:1). Alternatively, co-digestion with dairy or food waste in anaerobic digesters yields biogas at 250–400 m³/tonne VS.
Concentrated pomace syrup (60–70% solids) is a high-energy feed supplement for ruminants. Must meet DAERA/Defra or local pathogen reduction standards via pasteurisation or acidification.
Equalisation and process train sizing for extreme flow variation between crush and off-season.
| Parameter | Value | Notes |
|---|---|---|
| Average off-season flow | 20 m³/day | Barrel washing, bottling, general cleaning |
| Crush peak flow | 200 – 1,000 m³/day | 2–6 week harvest window |
| Peak-to-average ratio | 10 – 50× | Highest in beverage industry |
| Equalisation HRT at peak | 12 – 24 hours | Depends on crush duration and buffer need |
| Required EQ tank volume | 200 – 1,000 m³ | Scaled to peak daily flow |
A 500-tonne crush capacity winery operating an 8-week harvest with a peak flow of 400 m³/day requires:
Designing for the peak ensures compliance during crush; designing for the minimum ensures biological stability during the quiet months.
Realistic project scopes and budgets for winery and cidery wastewater treatment systems.
| Project Name | Medium Winery – 500 Tonne Crush |
| Crush Capacity | 500 tonnes grapes / season |
| Peak Flow | 400 m³/day (8-week crush) |
| Influent | BOD 5,000 mg/L, COD 10,000 mg/L, TSS 2,000 mg/L, pH 3.5–5.0, SO2 200 mg/L |
| Treatment Process | Pomace screen → 600 m³ EQ → pH adjustment → SO2 stripping → DAF → MBBR → clarifier → discharge |
| Key Equipment | Rotary drum screen (3 mm), 600 m³ equalisation tank, DAF unit (50 m³/hr), MBBR (800 m³ bio-volume), screw press (500 kg DS/hr), polyelectrolyte station |
| Project Name | Large Winery – 2,000 Tonne Crush |
| Crush Capacity | 2,000 tonnes grapes / season |
| Peak Flow | 1,200 m³/day (6-week crush) |
| Influent | BOD 6,500 mg/L, COD 12,000 mg/L, TSS 2,500 mg/L, pH 3.0–4.5, SO2 350 mg/L, polyphenols 400 mg/L |
| Treatment Process | Rotary screen → 1,500 m³ EQ → pH adjustment / SO2 strip → DAF → MBBR → lamella clarifier → UV disinfection → discharge |
| Key Equipment | Rotary screen (2 mm), 1,500 m³ EQ (2-cell), DAF (120 m³/hr), MBBR (2,500 m³ bio-volume), lamella clarifier (80 m³/hr), UV system (150 m³/hr), belt press (1,000 kg DS/hr), SCADA panel |
| Project Name | Craft Cidery – 200 Tonne Apple Crush |
| Crush Capacity | 200 tonnes apples / season |
| Peak Flow | 150 m³/day (4-week crush) |
| Influent | BOD 4,000 mg/L, COD 8,000 mg/L, TSS 1,500 mg/L, pH 3.5–5.0, low SO2 |
| Treatment Process | Screw screen → 250 m³ EQ → pH correction → DAF → compact SBR → discharge |
| Key Equipment | Screw screen (3 mm), 250 m³ EQ tank, DAF (20 m³/hr), compact SBR (2-tank, 150 m³ each), screw press (200 kg DS/hr) |
Why Choose Our Winery & Cidery Solutions
Equalisation and process trains engineered for extreme seasonal variation from off-season trickle to harvest peak without compromising treatment quality.
Dedicated SO2 stripping and neutralisation ensures discharge below 1 mg/L, protecting receiving waters and meeting stringent environmental consents.
Specialised DAF polymers and coagulants target tannin and polyphenol removal, preventing colour carryover and toxicity in biological stages.
Integrated screw and belt press systems reduce pomace volume by 75%, cutting transport rates and producing stabilised cake for compost or feed.
SCADA-controlled systems automatically adjust aeration, chemical dosing, and sludge wasting to match off-season and crush-season operating modes.
Biological stages engineered for stable operation at 5–10% of design capacity, avoiding biomass starvation during quiet months without manual intervention.
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