Storing Tofu, Tempeh and Mushroom Fillings: Fridge and Freezer

Short answer: Cooked tofu, tempeh, seitan and mushroom fillings keep about 3–4 days in the fridge at 4°C (40°F) or below, the USDA guideline for leftovers. Frozen at −18°C (0°F) they stay safe indefinitely and keep their best quality for about 2–3 months. Opened raw tofu should be kept covered in fresh water in the fridge and used within a few days. Thaw in the fridge, never on the counter, and reheat until steaming hot.

Fillings are the heart of a banh mi and also the most perishable part. Unlike pickles, which are protected by vinegar, a lemongrass tofu or a soy-glazed mushroom mix is a moist, low-acid cooked food, the kind that bacteria grow in readily if it is left warm or kept too long. The good news is that most plant-based fillings store and freeze well, some even improve. This guide covers each one, from raw packages to cooked batches, with a quick reference table and the mistakes that most often spoil a good batch.

The ground rules from USDA

The USDA Food Safety and Inspection Service sets out a few rules that apply to every cooked filling in this guide. Refrigerate cooked food within 2 hours of cooking, or within 1 hour if the temperature is above 32°C (90°F), which is often the case in a Vietnamese kitchen or on a summer day. Keep the fridge at 4°C (40°F) or below and the freezer at −18°C (0°F). Eat refrigerated leftovers within 3–4 days. Frozen food stays safe indefinitely, but quality declines over time. Thaw frozen food in the refrigerator, in cold water or in the microwave, never on the counter. Reheat leftovers to 74°C (165°F). A cheap fridge thermometer is worth having, because many home fridges run warmer than their dial suggests.

Quick reference table

The fridge times for cooked foods come from USDA leftovers guidance. Freezer times are quality guidelines, and "opened raw tofu" times reflect common manufacturer advice; follow your package if it says otherwise.

Tofu: raw, opened and cooked

Unopened packaged tofu belongs in the fridge until its date, unless the package is labeled shelf-stable (aseptic cartons). Once opened, rinse any leftover tofu, put it in a container, cover it completely with fresh cold water, and change the water every day. Many manufacturers suggest using it within about 3–5 days. Fresh tofu bought loose from an Asian market or a Vietnamese wet market has no package date, so treat it as very perishable and use it within a day or two.

Freezing raw tofu is a technique worth knowing, not just a storage trick. As the water inside freezes, ice crystals open up the structure, so thawed tofu is spongier, chewier and absorbs marinade better. Freeze it in the package or drained and sliced, thaw overnight in the fridge, then press firmly: the water pours out easily. Many cooks prefer this texture for banh mi fillings. Our plant-based fillings guides use it in several recipes.

Cooked tofu follows the 3–4 day rule. Crisp, fried tofu softens in the fridge as it absorbs moisture; re-crisp it in a hot pan or air fryer for a few minutes rather than microwaving it.

Tempeh and seitan

Tempeh freezes exceptionally well, raw or cooked, with little change in texture. Many cooks keep raw tempeh in the freezer and slice it straight from frozen, as it cuts more cleanly. Small grey or black spots on raw tempeh can be a normal part of the mold culture used to make it, but fuzzy mold of other colors, a slimy surface or an ammonia smell beyond a mild mushroomy aroma are signs to discard it. When in doubt, throw it out.

Homemade seitan keeps best submerged in its cooking broth, which stops it drying out. Freeze it in the broth in portion-sized containers. Thawed seitan slices well for banh mi "cold cuts".

Mushrooms and jackfruit

Raw mushrooms are best stored unwashed in a paper bag in the fridge, where they keep for several days; plastic traps moisture and makes them slimy. Cooked mushroom fillings and mushroom pâté follow the 3–4 day rule and freeze well for cooked uses, though thawed mushrooms release liquid, so drain them or warm them in a dry pan before using. Cooked jackfruit filling stores and freezes like other cooked leftovers. Opened canned jackfruit should be moved out of the can into a covered container and refrigerated.

Portioning for the freezer

How you pack fillings for the freezer decides how easy they are to use. Portion cooked tofu, tempeh or mushrooms into amounts for one or two sandwiches, about 100–200 g, rather than freezing one big block you have to thaw all at once. Freeze slices flat in a single layer on a tray lined with parchment for an hour, then move them to a freezer bag; they stay separate and you can take out exactly what you need. Press the air out of bags, or use rigid containers filled close to the top, to limit freezer burn. Write the contents and the date on masking tape, because frozen tofu and frozen seitan look surprisingly similar after a few weeks.

Thawing and reheating without ruining texture

The safest method is overnight in the refrigerator: move tomorrow's portion from the freezer to the fridge after dinner. For faster thawing, seal the food in a leak-proof bag and submerge it in cold water, changing the water every 30 minutes; small portions thaw in about an hour. The microwave defrost setting is safe if you cook or reheat immediately afterward.

For reheating, a skillet over medium-high heat with a teaspoon of oil restores crispness to tofu and tempeh in 3–4 minutes. An air fryer at 180°C (350°F) for 4–6 minutes works well too. The microwave is fine for saucy fillings like glazed mushrooms or jackfruit; cover and stir halfway so they heat evenly to steaming hot throughout. Some people like tofu cold in a banh mi, which is fine for food you have stored properly within its fridge window; if it was frozen, thaw it in the fridge first.

Signs a filling has gone bad

• Sour, yeasty or unpleasant smell, especially from tofu or cooked mushrooms
• Slimy surface or cloudy, thick soaking water on tofu
• Visible mold, or fuzzy patches on tempeh that differ from its normal white culture
• Bloated packages or containers
• Any cooked filling that has sat out for more than 2 hours, even if it looks and smells fine

The last point matters most. The bacteria that cause foodborne illness usually do not change how food looks, smells or tastes, according to USDA. Time and temperature, not your nose, are the real test. More guidance on safe meal prep is in our meal prep and storage section.

Sources

• USDA Food Safety and Inspection Service – fsis.usda.gov (Leftovers and Food Safety; The Big Thaw)
• FoodSafety.gov – foodsafety.gov (Cold food storage chart)
• USDA FoodData Central – fdc.nal.usda.gov

Frequently asked questions