Practical guide to reducing the cost, odors, and volume of food waste

Bio-waste (food waste) is the “heaviest” and most demanding waste stream in a hotel: it is produced daily, generates odors, requires a clean handling routine, and directly affects operating costs. On-site management (within the hotel) provides control, measurable results, and better hygiene in the back-of-house.

In practice, the two solutions that work best in a hotel environment are:

• On-site composting (in-vessel / mechanical composting)

• On-site drying (food waste drying)

Let’s see what each one means, where it fits best, and how it can be implemented without disrupting the kitchen’s daily operations.

What a hotel’s “food waste” includes

It almost always comes from:

• Kitchen / preparation (peelings, trimmings, production leftovers)

• Buffet (unsold/unserved food)

• Plate returns (plate waste)

• Where applicable: greens/prunings (handled differently, case by case)

Critical point: success starts with source separation. The fewer “foreign” materials (plastics/packaging/metals), the better the performance—whether composting or drying.

Solution 1: On-site composting (in-vessel / mechanical composting)

Operating principle

In-vessel composting is a controlled aerobic biological process inside a closed chamber/unit, with monitoring and adjustment of critical parameters (aeration, mixing, moisture, temperature, retention time). Under the right conditions, the organic fraction (food waste) is converted into a stabilized material (compost or pre-compost/stabilized organic output), depending on the technology and operating protocol.

Typical subsystems/stages

• Pre-treatment (where applicable): size reduction/homogenization of inputs

• Mixing and aeration: mechanical mixing and/or forced aeration to maintain aerobic conditions

• Controlled biodegradation: temperature profile and moisture kept within operational limits

Suitability for hotels

On-site composting is particularly suitable when:

• There is a strategic goal for circular on-site management, reducing transport and waste flows.

• There is suitable space (back-of-house/technical area) with access for safe feeding and servicing.

• A clear operational responsibility can be assigned (shift supervisor/feeding procedure/basic checks).

• A realistic plan exists for the produced material (internal use for landscaping where practical, or organized removal as stabilized output).

Critical technical success factors

• Input quality control (contamination control): plastics, glass, or metals reduce performance and increase operational burden (cleaning, wear, degraded output quality).

• Correct mix formation: where required, use of bulking/structural material or additives to improve porosity, aeration, and moisture adjustment.

• Stable operating routine: daily/regular feeding and basic checks to avoid peaks that affect odors and process stability.

Solution 2: On-site drying of bio-waste (food waste dryer)

Operating principle

On-site drying is a thermomechanical process that reduces the moisture content of bio-waste through controlled heating, air circulation/recirculation, and mixing. The output is a drier, more stable, and significantly lighter residue, with reduced fermentation potential and therefore a reduced odor footprint during temporary storage and handling.

Typical subsystems/stages

• Drying chamber with mixing/agitation mechanism

• Ventilation/exhaust system to manage water vapor and stabilize the process

• Odor management system (filters and, where required, a biofilter/specialized air treatment)

• Cycle programming (time, thermal profile, daily routine)

Suitability for hotels

On-site drying is particularly suitable when:

• The goal is maximum reduction of weight/volume and optimization of temporary storage/internal movement.

• There are space constraints, or a lower process complexity is preferred compared to composting.

• Predictability (cycles, repeatability) is required and variability from feedstock composition/moisture must be minimized as much as feasible.

Critical technical success factors

• Energy efficiency and correct sizing: select capacity and cycles based on real kg/day and seasonality to avoid under/oversizing and inefficient operation.

• Final residue management: a clear operational plan for removal/disposal of the dried material and its storage requirements.