Scalding Poultry by Steam at Subatmospheric Pressures

Abstract

The poultry industry needs to replace the long existing, almost universally used immersion scalding method by methods that would be more sanitary and esthetically acceptable, provide a safer, more stable product, and minimize pollution and water requirements. There have been several efforts to develop scalding by mixtures of air and steam maintained at proper temperatures; commercial models have been built and tested but so far no substantial commercial use developed.This report describes preliminary tests that establish the possibility of scalding birds for feather removal by exposing them to an atmosphere of steam under controlled subatmospheric pressure and temperature conditions. Scalding was carried out in a cylindrical metal vacuum chamber, connected to a mechanical vacuum pump and condenser and a manually controlled inflow of steam. The system permitted establishment of uniform steam atmospheres of desired temperatures (± 1°F.) within 15 seconds, in the range from 52°C. (125°F.) to 60°C. (140°F.),…