Onion Peeling Machines for Professional Kitchens: When They Pay Off

How an onion peeling machine works

The produce goes into a drum lined with carborundum, a very hard abrasive. As the drum turns, the onions rub along the wall and the skin comes away. Once the set time has elapsed the cycle stops, and a skin ejector releases the peeled produce.

What sets these machines apart from simple peelers is the water. In the FLOTT machines from Flottwerk, the peeling water collects inside the drum instead of draining away immediately. The onions are therefore washed at the same time, the cushion of water softens the impact against the drum wall, and consumption drops because fresh water is not running through continuously. At the end of the cycle the machine empties by slowly restarting, so the peeled produce is not flung out.

For the choice of model, one point matters above all. The carborundum coating is matched to the produce. Anyone working mainly with garlic needs a different version from someone peeling onions. The peeling system is selected to suit your focus when you order; further systems can be retrofitted if your requirements change.

The three sizes compared

Flottwerk builds the ZS range in three sizes. The first figure for capacity applies to onions, the second to garlic, the third to other bulb and root vegetables.

At 56 centimetres wide, the smallest machine still fits into a cramped preparation kitchen. The ZS 25 needs almost a metre of floor space and, at just under 1.20 metres, is too tall to slide under a worktop.

A note on the throughput figures. The kilograms per hour refer to pure machine time with continuous loading. In practice, filling, emptying and trimming come on top. Budget realistically for half to two thirds of the catalogue figure.

What the machine will not do for you

A peeling machine peels — it does not trim. The root end and neck stay on the onion, and depending on variety and storage time, individual pieces of skin remain. Both have to be finished by hand. Anyone buying in the expectation that onions go in one end and ready-to-use produce comes out the other will be disappointed.

Here is the realistic picture. The actual peeling work, removing the dry outer skin, is handled entirely by the machine. The trimming remains, but it is considerably quicker than peeling from scratch by hand — and it can be done sitting down while the next batch runs.

And then there are the skins. They come away with the peeling water, in substantial quantities. Without a collector, everything ends up in the drain, and after a few weeks that drain is blocked. A skin collector with sieve is therefore basic equipment, not optional extra. It is available in plastic from around 150 euros and in stainless steel for continuous use.

When it pays off

The following calculation is a model with its assumptions laid open, not a guarantee — your figures will depend on variety, staff and organisation. It assumes four minutes per kilogram for hand peeling including trimming, one minute per kilogram of trimming when using the machine, 25 working days per month, and 20 euros per hour as fully loaded staff costs.

The threshold therefore sits at roughly 20 kilograms a day. Below that, the machine takes years to pay for itself and the money is better invested in other equipment. From 40 kilograms the case becomes clear-cut — typically kebab businesses, staff canteens, snack kitchens that process their own onions, and operations preparing for several sites.

At 80 kilograms a day, however, the ZS 3 is no longer the right choice: 20 batches of 4 kilograms means constant refilling. The ZS 10 is the sensible option here, even though the payback calculation looks shorter for the smaller machine.

Two items are missing from the table that belong in the calculation. Water and electricity barely register — 0.25 kW is less than a kettle. More noticeable is that machine-peeled onions lose slightly more flesh than careful hand work. If your margins are tight, allow two to five per cent extra raw produce.

Connections: the point that gets overlooked

All three machines run on 400 volt three-phase power. A standard socket will not do. If there is no three-phase supply in your preparation kitchen, you will need an electrician — a mid three-figure sum depending on the distance to the distribution board, and more in awkward cases.

Add to that a water connection (DN 15 to DN 25 depending on model) and a drain within reach. Sort both out before you order. We see it regularly: the machine arrives and the connection is missing.

The machines are built to stand on the floor. To bring one up to working height and make the floor underneath easier to clean, add the mobile base frame.

Safety and maintenance

A drum spinning with an abrasive lining is not a harmless device. The FLOTT machines therefore have a personnel protection circuit: the drive stops the moment the filling lid, housing lid or discharge flap is opened. After a power cut, a restart lock prevents the machine from starting up again by itself.

Wear mainly affects V-belts, seals and bearings — those fall due after a few years of continuous operation. Flottwerk offers pre-assembled service kits for this, from a small set covering belts and safety switches to a large package with all seals and ball bearings. The thinking behind it is simple. A cracked acrylic lid or a lost cap nut otherwise brings preparation to a halt for days until the spare part arrives. With the kit in the cupboard, such faults are fixed in minutes.

The machines are made entirely of stainless steel and built in Germany. Given the service life we are talking about here, that is not an advertising line but the difference between an investment for ten years and one for three.

Frequently asked questions

The models in our shop

• Onion and garlic peeling machine FLOTT ZS 3 — 4 kg of onions per batch, up to 100 kg/h, €6,706.28 excl. VAT. For businesses from around 20 kilograms a day.
• Onion and garlic peeling machine FLOTT ZS 10 — 12 kg per batch, up to 300 kg/h, €10,834.28 excl. VAT. The size for canteens and kebab businesses with daily processing.
• Onion and garlic peeling machine FLOTT ZS 25 — 25 kg per batch, up to 600 kg/h, €15,908.28 excl. VAT. For central kitchens and operations preparing for several sites.

You will find all models and the matching accessories under peeling machines, and the full range under Flottwerk. If potatoes rather than onions are your concern, our guide to the potato peeling machine will help; for cutting after peeling, read the guide to vegetable cutters. Kebab businesses will find the right grill technology in the kebab grill guide.