Wikipedia
A slow fire is a term used in library and information science to describe paper embrittlement resulting from acid decay. The term is taken from the title of Terry Sanders' 1987 film Slow Fires: On the preservation of the human record.
Solutions to this problem include the use of acid-free paper stocks, reformatting brittle books by microfilming, photocopying or digitization, and a variety of deacidification techniques.
Usage examples of "slow fire".
The farther they rode, the worse the smell became - it had a rich warmth to it, Dallandra decided, as if the filth were being stewed over a slow fire.
The main course had been ham, smoked over a slow fire, served with fat-dipped bread and roasted beans with chilies.
An almost indescribable sensation flowered in her loins, spreading like a slow fire through her belly and thighs into her chest and arms and down to her ankles.
A slow fire was lit and kept burning upon the rock until it had heated to a dull glow.
His penis stiffened, grew, pulsed with waves of slow fire which swelled when they reached his penis's root, then burst to expand throughout his body as he merged with the rippling reflections and with the water through which he waded, mechanically scattering pellets of insect poison.
Once we caught one of the hairy men with our vine nets and tied him over a slow fire and left him there until he died and the thing sucked his screams moving in my face like smoke and no one could eat the flesh-fear of the hairy man and there was a smell in the cave bent us over.
Bad times those general sir, there were no secrets of state that were not in the public domain, there was no order that was carried out with complete certainty ever since the exquisite corpse of General Rodrigo de Aguilar had been served up at the banquet table, but he didn't care, he didn't care about the stumbling of power during the bitter months in which his mother was rotting away in a slow fire in the bedroom next to his after the doctors most adept in Asiatic scourges decreed that her illness was not the plague, or scabies, or yaws, or any other Oriental pestilence, but some Indian curse that could only be cured by the one who had cast it, and he understood that it was death and he shut himself up to care for his mother with the abnegation of a mother, he stayed to rot with her so that no one would see her cooking in her stew of maggots, he ordered them to bring her hens .
Even your occasional Moroccan school-teacher hung over a slow fire three days ago can't compete with that stuff.
Same for all of his brothers, but you could have roasted them over a slow fire before they admitted to such weakness in front of their baby sisters.