What heat, cold and time do to your food.

Frozen. Freezing slices halts staling and — crucially — converts some of the starch into resistant starch. Toasting straight from frozen can cut the blood-sugar spike of a slice by up to 30–40% versus fresh bread.

Chilled. A loaf in the fridge stales fast (starch retrogrades in hours, not days). The upside: that retrograded starch behaves more like fibre. The downside: texture turns rubbery. Freeze instead of fridging.

Cooked. Re-toasting bread that has been frozen then thawed compounds the effect — more resistant starch, drier crumb, deeper flavour. Sourdough wins twice: its acidity already slows starch digestion.

Frozen. Cooked grains freeze beautifully. Thawing and gently reheating preserves the resistant starch that formed during cooling — a free fibre upgrade.

Chilled. Cook, cool uncovered, then refrigerate overnight. Type 3 resistant starch forms as the amylose recrystallises. White rice cooled 24h can have roughly double the resistant starch of freshly steamed.

Cooked. Reheating does NOT undo the resistant starch — it's heat-stable up to ~130°C. Microwave or stir-fry cold cooked grains; don't boil them back to fluffy.

Frozen. Freezing raw potato turns to mush. Freeze them cooked and cooled — gnocchi, cubed roasties, mash patties — to lock in resistant starch and prevent freezer burn.

Chilled. Potato salad is the classic example: a boiled-then-chilled potato has ~3× the resistant starch of a hot one, and a markedly lower glycaemic load.

Cooked. Roasting at high heat caramelises sugars (Maillard) but also gelatinises starch. Cool fully before reheating to bank the fibre benefit.

Frozen. Cooked pasta freezes well in portions. Pre-toss with olive oil so strands don't fuse. Reheat in a hot pan, not boiling water.

Chilled. Al dente pasta, drained, oiled and refrigerated overnight, gains resistant starch and drops in glycaemic index by roughly a quarter.

Cooked. Overcooked pasta gelatinises more starch and digests faster — keep it firm. Reheating cold pasta in a sauce is better than serving it freshly boiled if blood sugar matters.

Frozen. Cooked pulses freeze indefinitely with no loss of fibre or protein. Freeze in their cooking liquid to keep skins intact.

Chilled. Already high in resistant starch raw; cooling cooked pulses bumps it further. A 24h fridge rest also mellows the flavour.

Cooked. Pressure-cooking destroys lectins and phytic acid more thoroughly than simmering, improving mineral absorption. A splash of vinegar near the end firms the skins.

Frozen. Freezing forms ice crystals that rupture cells — small loss in juiciness, no loss in protein. Vacuum-pack or wrap tightly; freezer burn is oxidation, not spoilage.

Chilled. Dry-aging in the fridge (uncovered, on a rack, 1–4 days) concentrates flavour and tenderises via natural enzymes. Always cook to safe internal temps.

Cooked. Cooking denatures proteins but does not destroy them. Resting meat 5–10 min after cooking lets juices redistribute — slicing too early loses up to 15% moisture.

Frozen. Freeze raw within 2 days of purchase. Thighs survive freezing far better than breast — less water loss on thaw.

Chilled. Brining in salted water or kefir for 4–12h before cooking helps the muscle hold moisture through the heat.

Cooked. Poaching and sous-vide keep proteins tender; high heat tightens them and squeezes water out. Once cooked, chill within 90 minutes and use within 3 days.

Frozen. Frozen-at-sea oily fish often beats 'fresh' counter fish on omega-3 retention. Thaw slowly in the fridge to avoid texture loss.

Chilled. Best eaten within 1–2 days of catch or thaw. Curing (salt + sugar + dill) chemically 'cooks' the protein without heat — gravadlax is a fridge transformation.

Cooked. Gentle heat (≤60°C internal) protects omega-3s. Frying at high temp oxidises them; bake, steam or pan-sear briefly.

Frozen. Whole eggs in shell crack. Whisk and freeze in ice-cube trays — perfect for batch baking. Whites freeze flawlessly; yolks need a pinch of salt to stop them gelling.

Chilled. UK eggs are sold unrefrigerated but last longer in the fridge once home. Older eggs peel more easily when hard-boiled (a 7-day-old egg is the sweet spot).

Cooked. Cooking denatures egg protein and boosts its digestibility from ~50% (raw) to ~90% (cooked). Hard-boiling reduces some B-vitamins; soft-boiling preserves them.

Frozen. Freezing kills most live cultures and splits the texture — fine for cooking, poor for spooning. Freeze hard cheese grated for cooking only.

Chilled. Live cultures keep working slowly in the fridge — kefir gets tangier and lower in lactose over 5–7 days. Fibre supplements like psyllium swell more in cold dairy.

Cooked. Heating above 70°C kills the probiotics. If you're after gut benefits, stir kefir or skyr in off the heat.

Frozen. Frozen at the peak of ripeness, berries often have more polyphenols than 'fresh' ones shipped underripe. Vitamin C loss is small (<10%).

Chilled. Wash leafy greens, spin dry, store in a sealed box with a paper towel — they'll keep crisp for 7–10 days, losing only minor folate.

Cooked. Brief steaming actually increases bioavailable lutein and beta-carotene in kale and spinach. Boiling leaches water-soluble vitamins — keep the cooking liquid for stock.