"Jasmin, listen closely." He waited until she met his gaze, ensuring he had her full attention. "This next part involves heat and the lye solution we made. The danger increases. The lye, when mixed with the hot fat, will react. It will generate its own heat. There might be fumes – irritating, not poisonous, but we keep the door cracked for ventilation." He pointed towards the slightly ajar door. "Most importantly: slow and steady. We add the lye gradually. We stir constantly, gently. No sudden movements, no splashing. If any of this mixture gets on your skin, even through the gloves, rinse it immediately and thoroughly with cold water from that bucket. Understood?"
Jasmin nodded solemnly, her eyes wide but focused. The transformation from timid butcher's assistant to apprentice clandestine chemist was progressing rapidly, fueled by trust and the underlying promise of her mother's recovery. "Yes, my lord. Slow. Steady. Careful stirring. Rinse if splashed. I understand."
"Good." Lloyd placed the heavy iron cauldron securely over the growing fire, adjusting its position until it sat stably above the flames, receiving even, moderate heat. "Now, the fat."
Together, they carefully scooped chunks of the solidified white tallow from the storage jar into the cauldron. Lloyd estimated the amount by eye, aiming for roughly two parts fat to one part lye solution by volume – a standard starting ratio he recalled from his fragmented Earth knowledge, adaptable later based on results.
"We need to melt this slowly," he instructed, picking up one of the long wooden paddles. "Gently now. We don't want it to scorch or splatter."
They took turns stirring the tallow as it gradually softened, liquefied, and warmed over the steady heat. The air filled with the rich, slightly heavy scent of melting beef fat. Lloyd kept a careful eye on the temperature, occasionally lifting the cauldron slightly off the direct flames if it seemed to be heating too quickly. He explained to Jasmin how judging the temperature by feel (holding a hand cautiously near the side of the pot) or by observing the fat's clarity and movement was crucial.
Finally, the tallow was fully melted, a clear, pale golden liquid shimmering in the cauldron, warm but not boiling. "Alright," Lloyd declared, taking a deep breath. "The critical moment. The lye."
He carefully measured out the required volume of the brownish lye solution into one of the earthenware bowls, using rough estimations based on the cauldron's size and the amount of melted fat. Then, positioning himself carefully, holding the bowl steady, he addressed Jasmin, who stood ready with the other long wooden paddle.
"Start stirring, Jasmin. Gently, constantly. A slow, steady swirl. Don't stop, no matter what."
Jasmin nodded, her knuckles white as she gripped the paddle, and began stirring the warm, liquid tallow with smooth, careful strokes.
"Here we go," Lloyd murmured, mostly to himself. He took the bowl of lye and began pouring it into the swirling fat. Not all at once, but in a thin, steady stream, moving the stream around the edge of the cauldron as Jasmin stirred.
The moment the lye hit the hot fat, there was a subtle change. A slight cloudiness appeared where the stream entered. A faint hissing sound, barely audible above the crackle of the fire. The rich, fatty smell was now tinged with that sharper, alkaline tang of the lye.
"Keep stirring," Lloyd urged quietly, his focus absolute as he continued the slow, steady pour. "Even pace. Keep the mixture moving."
He emptied the bowl, the full measure of lye now incorporated into the melted fat. The mixture in the cauldron looked… unpromising. Cloudy, slightly separated, like poorly mixed salad dressing. Droplets of fat seemed to resist combining with the watery lye.
"This is normal," Lloyd reassured Jasmin (and perhaps himself). "It takes time. The transformation doesn't happen instantly. Now, we stir."
And stir they did. Taking turns with the heavy wooden paddles, they maintained a constant, slow, deliberate motion, swirling the mixture round and round in the warm cauldron. Minutes stretched into what felt like hours. The initial cloudiness persisted, then slowly, almost imperceptibly, began to change.
"See that, Jasmin?" Lloyd pointed with his paddle. "It's becoming… thicker. Creamier. Less like oil and water, more like… like thin porridge."
Jasmin peered into the pot, her eyes alight with fascination despite her aching arms. "It is, my lord! It's changing color too, slightly lighter?"
"Emulsification," Lloyd explained simply. "The lye is starting to break down the fat. The two are beginning to truly combine, forced together by the heat and the constant motion. This is the start of saponification. The start of soap."