Can I cook rice ahead of time, and how do I hold it safely?

Yes — the risk in cooked rice is how long it sits warm, not the reheating. The two safe routes are hot-holding above 63°C and fast cooling into the fridge, and here is how to do each.

Difficulty: beginner
Time: 10 min
Read: 4 min
Safety: warning

Short answer

Cook the rice, then take one of two routes and never a route in between. Either hold it above 63°C continuously — a low oven in a covered dish, a bain-marie, a rice cooker on 'keep warm' that genuinely stays that hot — or spread it thin to cool within one hour, refrigerate, and use within 24 hours. What you must not do is leave it standing at room temperature or lukewarm for hours, because that is the window in which the toxin forms and reheating will not undo it.

The folk version of this — 'never reheat rice' — is wrong in a way that matters, because it makes people afraid of the harmless step and relaxed about the dangerous one. Reheating rice is fine. Leaving it out is what causes the problem, and no amount of reheating fixes rice that has already been left out.

Safety

Bacillus cereus spores are naturally present in dry rice and survive boiling. If cooked rice is left standing between roughly 8°C and 60°C, those spores germinate and some strains produce a heat-stable emetic toxin that reheating cannot destroy. The control is time and temperature, not reheating: cool cooked rice within one hour, refrigerate, use within 24 hours, and reheat only once until piping hot throughout. Rice held hot must be held above 63°C continuously, never lukewarm.

Where the real risk in cooked rice is, and it is not the reheating

Step by step

Understand what you are actually managing.Bacillus cereus is a soil bacterium and its spores are on dry rice as a matter of course. Boiling kills the growing bacteria but not the spores. If the cooked rice then sits warm, the spores germinate, the bacteria multiply, and some strains produce cereulide — a toxin that survives boiling. Cooking cannot remove the spores and reheating cannot remove the toxin. The only lever you have is not giving them the warm hours they need.
Decide before you cook whether you are holding hot or cooling.These are two complete routes and drifting between them is the failure mode. Rice for a meal in the next hour or two: hold hot. Rice for tomorrow, or for a batch: cool immediately. Rice that has been sitting on the hob 'until people are ready' for three hours is neither.
To hold hot, hold properly hot.Above 63°C, continuously. A covered dish in an oven at 80–90°C, a bowl over simmering water, or a rice cooker whose keep-warm setting genuinely holds that temperature. Check with a probe once so you know what your equipment does — many keep-warm settings sit well below 63°C, and a lukewarm rice cooker left on all evening is the classic version of this problem.
To cool, spread it out immediately.Tip the rice onto a wide tray or two in a thin layer as soon as it is cooked. Depth is what governs cooling speed — a deep pan of rice can stay warm for hours while a 2 cm layer on a tray is cold in twenty minutes. Do not put a hot lidded pan of rice in the fridge; it cools slowly and warms everything around it.
Get it in the fridge within one hour.One hour from the end of cooking to the fridge is the practical UK guidance and it is easily achievable with the tray method. Cover once it is cool. A fridge running at 5°C or below stops the bacteria multiplying.
Use refrigerated rice within 24 hours.One day, not the three or four you might allow another leftover. This is specific to rice and it is because the spores are already present and the fridge only slows them.
Reheat once, thoroughly, and eat it.Piping hot all the way through — steaming, above 75°C, stirred so there are no cold pockets. A splash of water and a covered pan, or the microwave with a cover and a stir halfway. Do not reheat a second time and do not put reheated rice back in the fridge.
Freeze if you want it to keep longer.Cool fast as above, then freeze in portions the same day. It keeps a month or more and reheats from frozen in the microwave in a few minutes. Freezing is the honest answer to 'I want cooked rice available all week'.

Tips

Cold cooked rice is better than fresh for fried rice — the grains have firmed up and separate cleanly. That is a genuine reason to cook it the day before, done properly.
Rinsing before cooking and salting do nothing for this. Neither removes spores.
The same rules apply to cooked pasta, cooked potatoes and cooked grains, though rice is the one where it bites most often because it is so often cooked in quantity and left standing.
Shop-bought pouches of cooked rice are commercially sterilised and sealed, which is why they sit on a shelf. Once opened, treat them exactly like rice you cooked yourself.

Common mistakes

Leaving the pan on the hob with the lid on 'to keep warm' — A covered pan off the heat passes slowly through the whole danger range and can sit there for hours. That is precisely the condition the bacteria need.
Believing that reheating makes standing rice safe — The toxin is heat-stable. Reheating deals with bacteria, not with what they have already produced.
Cooling a deep container in the fridge — The centre of a deep mass stays warm for hours and you have also warmed the fridge. Spread thin first.

Questions people ask

So is it actually safe to reheat rice?

Yes, if the rice was cooled quickly, kept refrigerated and is reheated once until piping hot. The 'never reheat rice' advice is a garbled version of a genuine risk that lives entirely in the cooling and standing, not in the reheat.

How long can cooked rice sit out at a party or buffet?

Treat it like any high-risk food on a buffet: no more than two hours at room temperature in total, or hold it above 63°C. In a warm room, shorter.

What does the illness look like?

Vomiting typically within one to five hours of eating, or diarrhoea after a longer interval, depending on which toxin type is involved. It is usually short-lived but genuinely unpleasant, and it is one of the more common causes of food poisoning traced to a takeaway or a buffet.