Steam vs Lye Peeling: Chemical-Free Steam for Fruit and Root Crops
Some plants still peel with caustic (lye) baths. Bigtem steam peelers use steam and water only: the Gentle steam peeler for peaches, tomatoes and peppers without lye, and the DORUK steam peeler for high-tonnage potatoes and root crops. This guide compares the methods with facts already published on Bigtem USA pages.
Bigtem USA engineering guide · updated October 2026
- Gentle steam peeling uses steam and water only — peach and tomato lines peel without lye.
- DORUK covers high-tonnage potatoes and root crops; Gentle covers fruit at lower pressure (8 bar peaches) and potatoes at 15 bar.
- Bigtem does not build chemical (lye) peelers; displacement is a steam (or abrasive/flame) path with NA support from Atlanta.
How steam peeling works
A batch of product is weighed into a pressure vessel. The vessel is sealed and filled with high-pressure steam while it rotates. Steam heats only the outer layer. When pressure is released in one step, moisture under the skin flashes to vapor and lifts the skin. A brush or dry-peel finisher then removes the loosened skin.
On the DORUK steam peeler, six vessel sizes cover about 3,300 to 61,700 lb/h (1.5 to 28 t/h) of potatoes on the Bigtem spec sheet (up to 15 bar). The Gentle steam peeler runs fruit such as peaches at lower pressure (8 bar on the spec sheet) without lye, and potatoes at 15 bar.
What lye peeling is (in brief)
Traditional chemical peeling softens or dissolves the outer skin in a caustic (lye) bath, then rinses and finishes the product. Bigtem USA does not supply lye peelers and does not publish bath concentrations, peel-loss percentages for caustic lines, or competitor brand names on this page. Plants comparing options usually weigh chemical handling and rinse streams against a steam-and-water process.
Side-by-side comparison
| Factor | Steam peeling (Bigtem DORUK / Gentle) | Lye (caustic) peeling |
|---|---|---|
| Method | Pressurized steam heats the outer layer; a sudden pressure release lifts the skin; a finisher removes it | Caustic (lye) bath softens or dissolves the skin; product is then rinsed and finished |
| Chemicals in the peeler | None. Steam and water only (Gentle FAQ: peach and tomato lines peel without lye) | Uses a caustic solution; plants must manage the chemical bath and rinse stream |
| Typical crops (Bigtem steam) | DORUK: potatoes, sweet potatoes, carrots, beets, celeriac. Gentle: peaches, tomatoes, peppers; also potatoes at higher pressure | Historically used on peaches, tomatoes and some other fruit/veg lines — Bigtem does not supply lye peelers |
| Spec-sheet capacity (Bigtem) | DORUK potatoes about 3,300 to 61,700 lb/h (1.5 to 28 t/h), six models. Gentle peaches about 6,600 to 25,400 lb/h (3 to 11.5 t/h) at 8 bar; potatoes about 6,600 to 44,100 lb/h (3 to 20 t/h) at 15 bar (four models) | Not published here — Bigtem does not offer chemical peelers |
| Utilities at the peeler | Steam (up to 15 bar on DORUK; fruit typically 8 bar on Gentle), water, compressed air, power, exhaust and condensate routes | Chemical make-up and bath control, rinse water, and steam/power as the line requires — plus chemical handling |
| Fruit integrity | Gentle runs fruit at lower pressure so skin lifts while flesh stays firm | Depends on bath strength, time and rinse; not characterized on this site |
| Batch or continuous | Batch vessel with a short cycle; continuous output after the finisher | Usually continuous immersion or spray bath (plant-specific) |
Steam capacities and pressures from the Bigtem Ordinary & Gentle Steam Peelers technical specifications (same figures as the product pages). No peel-loss %, caustic concentrations or third-party brand names are claimed here.
Where each Bigtem steamer fits
- Potatoes and root crops (high tonnage): DORUK — about 3,300 to 61,700 lb/h of potatoes across six models.
- Peaches, tomatoes, peppers: Gentle — peaches about 6,600 to 25,400 lb/h at 8 bar; steam and water only.
- Smaller potato / onion lines without steam: often abrasive — see steam vs abrasive.
- Fire-roasted peppers: flame roast-and-peel on the roasting & grill marking line (separate from steam).
When plants move off chemical peeling
Peach, tomato and pepper plants that want to peel without lye typically evaluate the Gentle steamer (steam and water) and confirm tonnage with the sizing calculator. Potato plants already on steam often stay on steam and use the replacement program when the vessel, controls or capacity no longer fit. Bigtem USA is the North American operation of Bigtem — sales, engineering and support from Atlanta; call (770) 999-0587 or request a quote.
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Steam vs lye peeling: FAQ
Does Bigtem still build chemical (lye) peelers?
No. Bigtem focuses on steam, abrasive, air and flame peeling. For peaches and tomatoes, gentle steam peeling replaces lye in most cases. See the peeling hub.
Does the Gentle steam peeler use chemicals?
No. It uses steam and water, so peach and tomato lines can peel without lye. See the Gentle steam peeler.
Which steamer for potatoes vs peaches?
How does this differ from steam vs abrasive?
Abrasive peeling uses rollers and water with no steam and no caustic. Lye peeling uses a chemical bath. Steam peeling uses steam and water only. See also steam vs abrasive.
Can we replace an aging chemical or steam peeler?
Yes. The steam peeler replacement program assesses footprint, utilities and shutdown window for aging peelers from any manufacturer, then configures a DORUK or Gentle system.
Where do the capacity numbers come from?
From the Bigtem Ordinary & Gentle Steam Peelers technical specifications already published on the DORUK and Gentle pages. Capacities are approximate and depend on crop, variety, size and condition.
Related: Gentle steam peeler · DORUK steam peeler · Steam peeler replacement · Steam vs abrasive · Sizing calculator
Planning to leave chemical peeling?
Send your crop, tonnage and steam pressure at the peeler. We recommend Gentle or DORUK and outline the utilities — no prices published; request a quote.