Tofu is often sold submerged in water in a sealed tub, but once you open it the original shelf life no longer tells the whole story. The unused portion has been exposed to hands, utensils and air. How you store it depends on whether it's a refrigerated block, shelf-stable unopened pack or freshly prepared tofu.
For an opened refrigerated block, the priorities are cleanliness, cold storage and following the manufacturer's after-opening instructions. Keeping it in clean water may be recommended for some firm tofu, but it isn't a universal instruction for every variety or brand.
Check which tofu you've bought
Firm and extra-firm tofu may be packed in water. Silken tofu can come in a different container, and some unopened aseptic packs are shelf-stable until opened.
Read the label before moving anything. A product that was shelf-stable sealed may still need refrigeration immediately after opening.
Flavoured marinated tofu and ready-to-eat smoked tofu also have their own storage directions.
Keep unopened packs as directed
For refrigerated tofu, keep it in the fridge and observe the use-by date. Store packs where raw meat juices cannot drip onto them.
If an unopened product explicitly says it can be stored at room temperature, follow the producer's directions for the sealed pack.
Don't assume a supermarket product is shelf-stable simply because you found a similar-looking box online.
Use clean hands and utensils
When you open the packet, use a clean knife or spoon to remove the required portion. Avoid dipping hands that have handled raw meat or unwashed vegetables into the container.
Pour away packing liquid according to the instructions. Keep the work surface clean so an otherwise suitable block isn't contaminated.
Cut the remainder into manageable pieces only when that suits your planned use.
Transfer the remaining block if needed
For ordinary water-packed firm tofu, some producers advise transferring unused tofu to a clean airtight container and covering with fresh cold water.
Other products advise simply covering and refrigerating without added water. The label takes priority.
Use a food-safe container large enough that the block isn't crushed by the lid.
Change the water where required
If the manufacturer's method calls for storage under water, use clean drinking water and refresh it on the schedule they recommend.
Water left stale for days can become unpleasant and doesn't make tofu immune from bacterial growth.
Do not store tofu in warm water on the kitchen counter. Cold storage remains essential.
Refrigerate promptly
Return opened tofu to the fridge as soon as you've taken the portion you need.
Keep it at the refrigerator's recommended temperature and use within the shorter after-opening period specified on the package.
Don't rely on the original unopened use-by date to justify keeping half a block for two weeks after opening.
Check for signs of spoilage
Tofu that's turning slimy, developing mould or smelling markedly sour or rotten may be spoiled. Discard it.
Different fermented tofu products have intentional strong aromas, but ordinary unfermented tofu should not develop an alarming smell in storage.
Taste testing questionable tofu isn't a suitable way to determine safety.
Can tofu be frozen?
Yes, many types of tofu can be frozen, particularly firm varieties used in cooked dishes. Freezing changes their texture as ice crystals form.
Thawed tofu often becomes more porous and sponge-like, which can help it absorb marinades. It won't return to its original fresh smooth consistency.
Silken tofu usually becomes grainy or separated after freezing, so consider how you intend to use it.
Drain before freezing
For a firm tofu block, follow a suitable freezing method and manufacturer guidance. Some recipes drain or press tofu first.
Portion into freezer-safe packaging and label with the date. Avoid freezing spoiled tofu just to avoid wasting the remainder.
When thawing, use the refrigerator and handle as a perishable food.
Pressing tofu for cooking
Pressing helps remove excess moisture from some firm tofu, making it easier to brown in a pan.
Wrap in clean suitable material and use a dedicated tofu press or a safely weighted plate. Don't crush a delicate silken block.
Pressing is a cooking-preparation technique, not a method of keeping tofu indefinitely after opening.
What about cooked tofu leftovers?
Tofu stir-fries, curries and soups are prepared dishes, not unopened tofu products.
Cool promptly, refrigerate and follow the storage requirements for the whole dish. A sauce containing meat or seafood may have additional considerations.
Reheat thoroughly if serving hot, avoiding multiple unnecessary heating cycles.
Tofu with a marinade
Commercially marinated tofu may have preservatives or packaging designed for a specific shelf life. Once opened, follow the label.
Homemade tofu in a sauce belongs in the fridge. A marinade isn't automatically a food-preservation treatment.
Oil, garlic and other ingredients can introduce additional safety concerns when left improperly stored.
Keeping tofu for packed lunches
Transport tofu salads and cooked dishes in suitable chilled containers, especially during warm weather.
Don't leave a tofu-based meal on a sunny dashboard until lunchtime and assume that a sealed box will keep it safe.
Follow school or workplace food-safety recommendations where applicable.
What if the pack swells?
Unexpected swelling, leaks or damaged seals on unopened tofu can indicate a problem. Don't use a pack with signs of compromised integrity.
If a newly purchased pack appears defective, contact the retailer or producer.
Never try to rescue a suspicious pack by boiling it for longer.
How much tofu should you buy?
If you regularly throw away half a block, look for smaller packages or plan two recipes close together.
A larger pack can be economical when you can cook or freeze the remainder promptly.
Check whether the tofu you're buying is already frozen or can be divided conveniently for future meals.
The after-opening routine
Read the pack, move unused tofu into a suitable clean container, keep it refrigerated and use it within the producer's stated after-opening period.
For water-packed firm tofu, follow any fresh-water instructions and replace that water as recommended. Freeze a sound surplus if a changed texture will work for your next recipe.