Boil Washing
It does help to put boil washing into historical context.
Before modern laundry detergents and indeed automatic/mechanical washing machines laundry as we all know was a three or four day long process.
Soaking items in cold water first (with a bit of washing soda or borax) came first. This lossened surface soils and more importantly protien based soils/oils (sweat, urine, blood, etc), and prevented those stains from being set. After the soak water was drained off or laundry taken out of the soaking bath, they were put into a large tub of boiling water or water that was heated and allowed to come to a boil. Boiling hot water combined with the detergency of soap (and probably washing soda and or borax, loosened soils and grime. Heat also caused textile fibers to swell further easing the release of soils from laundry. Boiling provided some sanitation and also killed the various vermin which were pretty common on bed/body linens and apparel until rather recently. Pests such as lice, bed bugs, fleas. In addition to boiling,mechancial action was provided in the way of a dolly stick.
Now, once the boiling/dolly sticking had been done, laundry would be lifted out of the wash tub and examined for any remaining soils/stains. These would be scrubbed out either on a washboard/sink or with a brush. Many people believe all laundry was scrubbed on a wash board, which usually was not true, but rather only stains/soils that remained after all that soaking/boiling. Until modern enzyme detergents came along, hot to very hot water was needed as mechanical action alone was not usually enough to shift heavy soils/stains from laundry. Commercial laundries back in the day were famous for being harsh on laundry. That was usually because the products used required very high wash temps to get the job done. As the prevous post stated, several years ago the average wash temp was around 160F for commercial laundries. This has come down recently to 140F and even 120F, the ideal temperature range for enzyme detergents to do their thing.
In Europe boil washing prevailed even after modern detergents came on the scene because of their preference for oxygen bleaches versus chlorine. Until recently sodium perborate was the favourite oxygen bleach in Europe/UK, and that bleach requires 140F and above temperatures to really get going. Even with bleach activators, best results are achieved with temps above 120F. Lower temps require longer contact times. Recently in reaction to EU banning borates in laundry products, sodium percarbonate has replaced sodium perborate. Sodium percarbonate oxygen bleach will work in warm, cool and even cold water without the need for activators, unlike perborate bleach.
The key to good laundry results is having the proper detergent to soil ratio regardless of water temperature. Commercial laundries spend lots of time with their chemical suppliers tweaking product to load size/soil level to achieve the best results. Without proper product dosing not only are soils and stains not removed, the soils redeposit themselves not only on the laundry, but inside the machine as well. This leads to the muck and "biofilm" seen inside some washing machines.
I tend to look at it like when one is washing dishes in the sink; if enough soap is in the water, oils are suspended and dishes are clean. OTOH if too little product is used oils and muck cling not only to dishes but the sides of the sink and anything else the dirty water touches.
L.
