The Verification Venue · a kitchen rule, rebuilt from the heat equation

The Roast Keeps Cooking After You Pull It

Every recipe says to rest the meat. Most explain it the same wrong way: that cooking "pushes the juices to the center," and resting lets them flow back out. That story is folklore. One reason is carryover cooking: the hot outer shell keeps cooking the core by conduction after the oven is off. Here it is, live.

The shell of a roast comes out far hotter than the middle. Heat doesn't stop at the oven door; it keeps flowing down the temperature gradient, from the scorching outside into the cool core, for many minutes. So the core temperature keeps climbing after you pull it. Drag the moment you pull the roast and watch the core overshoot your target — the whole curve is integrated live from the heat equation, not played back.

drag the pull line ← → · or use the slider below

Core when you pull

63.0 °C

your target / doneness

Carryover overshoot

+13.2 °C

core keeps rising, oven off

Peak core (after rest)

76.2 °C

medium-well → well done

Pull from oven at core — 63.0 °C

Pull early. The overshoot finishes the job. With the other controls at their defaults, pulling at 48 °C reaches about 63.4 °C during the 30-minute rest, above the cited medium-rare range of 54–57 °C.

Roast size (radius) — 5.0 cm

A bigger roast stores more shell heat and carries over more — a thin steak barely carries at all.

Oven temperature — 175 °C

Hotter oven → hotter shell → bigger carryover. High-heat roasts overshoot well past the typical band.

Rest time — 30 min

The core peaks part-way through the rest, then everything cools together toward the room.

core temperature held fixed by assumption

Turn on the comparison and the line is flat because the code holds the core temperature fixed. Moving water, including "juice", can carry thermal energy; this line does not simulate moisture redistribution. The carryover curve climbs, consistent with the rise recorded by a probe thermometer. This comparison shows what the heat model predicts, not whether water moves during rest.

The check — every number recomputed in front of you

The curve above is integrated live by a 1-D radial finite-difference solver — the exact same code as the offline verifier. For your current settings:

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The four examples below show how size and oven temperature change the computed carryover. The published typical range (≈3–14 °C / 5–25 °F) is a comparison, not a bound on this model:

roast	oven	pull	peak	overshoot

Meat thermal diffusivity is α = 1.22×10⁻⁷ m²/s, computed live from α = k/(ρ·c) with sourced (k, ρ, c) for cooked lean meat — squarely in the published 1.0–1.7×10⁻⁷ band. Run it yourself: node research/the-roast-keeps-cooking/verify-the-roast-keeps-cooking.mjs.

What's exactly modelled, what's idealised, and the one number to distrust

Exactly modelled (heat transport). The core curve is the numerical solution of the spherical heat equation T_t = α(T_rr + (2/r)T_r) by an explicit finite-difference scheme, run stably (Fourier number 0.15 ≤ ⅙, the binding limit at the center node). The carryover overshoot is a genuine prediction of that PDE: with the oven off, the shell is still much hotter than the core, so heat keeps flowing inward until the gradient flattens. This part is physics, not decoration.

The free choices (named, not hidden). Thermal diffusivity varies with cut, fat content, and water phase — it shifts during protein denaturation and near freezing — so we use a single representative value (k=0.45, ρ=1050, c=3500 → α≈1.22×10⁻⁷) and quote the range, never a false "true" number. The oven heating uses a convective boundary with an effective film coefficient chosen so the surface tracks the measured roast plateau (~90–110 °C), capped at boiling to stand in for evaporative cooling — real meat surfaces stay near 100 °C while wet. The rest phase cools by natural convection to room air (h≈9 W/m²K). The overshoot depends on these choices: changing only the oven coefficient from 7 to 10 W/m²K gives about 16.4 °C with the other defaults unchanged. The AIDIC study estimates an oven coefficient near 10 W/m²K. Carryover persists in this comparison, but 3–14 °C is not a bound on the model.

What's only schematic (moisture). This sim models heat exactly and moisture loss only schematically. The second real reason resting helps — water-holding capacity recovers as the protein gel cools, so a rested cut loses less juice when sliced — is chemistry we do not simulate here; we only name it. And resting is a genuine trade-off, not a free win: a long rest also lets a crisp crust go soft (AmazingRibs argues this can hurt bark). Treat the page as a proof of the carryover mechanism, not a verdict that you should always rest for 30 minutes.

The myth, precisely. "Cooking pushes juice to the center; resting lets it flow back" implies a measurable inward-then-outward migration of free water. Feyissa's Table 4-2 found no increase in central water content during roasting; later work noted occasional rises near the centre. The samples were frozen immediately, so this did not test redistribution during rest. Water is held within the muscle structure, not all tightly bound to protein. The flat comparison above holds the core fixed by assumption; it does not simulate water movement. Carryover is a heat-transfer mechanism, and this simulator does not settle the moisture question.

Corrections

Corrected 2026-10-14: This page presented carryover cooking as the only reason to rest meat. The cited accounts also discuss moisture retention during cooling; found by the assay line, 2026-10-14.

Corrected 2026-10-14: This page said studies did not find an inward-then-outward water pattern. The experiment reported in Feyissa's Table 4-2 froze samples immediately after roasting and did not test redistribution during rest; found by the assay line, 2026-10-14.

Corrected 2026-10-14: This page advised pulling near 48 °C for medium-rare. With all other controls at their defaults, the model reaches 63.4 °C during a 30-minute rest, above the cited 54–57 °C range; found by the assay line, 2026-10-14.

Corrected 2026-10-14: This page said moving water carries no heat and presented a flat temperature as the prediction of juice redistribution. Moving water can transport thermal energy; the flat line is imposed by the code, which does not model moisture transport; found by the assay line, 2026-10-14.

Corrected 2026-10-14: This page said reasonable parameter changes keep carryover within 3–14 °C. Changing only the oven heat-transfer coefficient from 7 to 10 W/m²K gives 16.4 °C in the model with other defaults unchanged; found by the assay line, 2026-10-14.