KeepsUntilSearch My fridgeDairy Products & Eggs · USDA FoodKeeper

How long does Cheese last in the fridge once opened?

5 kinds · each with its own window

Cheese, hard such as cheddar, swiss, block… · Once opened · in the fridge

Use by3 weeks to 4 weeks

Counted from the day you opened it

Safety limit · past it, throw it out

How this date is worked out

From KeepsUntilIt is past the dateWhat to do when the window has run out, and when tasting is not a test Where these numbers come fromThe USDA source, the parse rules and what this site cannot tell you Every food on the siteOne page, every product, longest first

Turning the range into a date

Cheese (hard such as cheddar, swiss, block parmesan) keeps 3–4 weeks in the fridge once opened. Each kind gets its own dated rows here, 9 rows across the 5 the USDA lists under this name, because a date is only worth printing against the window it belongs to.

Cheese, hard such as cheddar, swiss, block parmesan

In the freezerUse by6 months after the day you bought it
Unopened · in the fridgeUse by6 months after the day you bought it
Once opened · in the fridgeUse by3 weeks to 4 weeks after the day you opened it

Cheese, parmesan; shredded or grated

Unopened · in the fridgeUse by12 months after the day you bought it

Cheese, shredded; cheddar, mozzarella, etc.

In the freezerUse by3 months to 4 months after the day you bought it
Unopened · in the fridgeUse by1 month after the day you bought it

Cheese, processed slices

Unopened · in the fridgeUse by3 weeks to 4 weeks after the day you bought it

Cheese, soft such as brie, bel paese, goat

In the freezerUse by6 months after the day you bought it
Unopened · in the fridgeUse by1 week to 2 weeks after the day you bought it

Cheese, hard such as cheddar, swiss, block… · Unopened · in the fridge

6 months

Counted from the day you bought it

6.4×

Cheese, hard such as cheddar, swiss, block… · What opening the package costs180 days sealed in the fridge ÷ 28 days open in the fridge

The USDA rates 5 kinds of this separately

Cheese, soft such as brie, bel paese, goat keeps 1 week, which is shorter than the window this page answers with. The USDA files 5 separate entries under this name, each listed below with its own windows, and they do not keep for the same time: at its best the shortest-keeping of them holds 1 week to 2 weeks outside the freezer, the longest 12 months.

What opening the package actually costs

Opening the package is the decision that settles this page. Sealed, the item holds 6 months sealed in the fridge; once open it holds 4 weeks open in the fridge, the same food measured in weeks instead of months, a drop of 6.4 times. On the same shelf it sits 4 of 31, between Margarine at 6 months and String Cheese at 5 months. Cheddar, swiss and parmesan are the same food in the source list.

Every storage figure the USDA publishes for this item

The USDA rates this item cold or frozen and never at room temperature: no pantry figure exists for it, as for 222 of the 466 foods in the data that get no pantry time at all. The source also indexes it as cheddar, swiss, parmesan and shredded.

Cheese, hard such as cheddar, swiss, block parmesan

In the freezer6 months
Unopened · in the fridge6 months
Once opened · in the fridge3 weeks to 4 weeks

Cheese, parmesan; shredded or grated

In the freezernot recommended
Unopened · in the fridge12 months

Cheese, shredded; cheddar, mozzarella, etc.

In the freezer3 months to 4 months
Unopened · in the fridge1 month

Cheese, processed slices

In the freezernot recommended
Unopened · in the fridge3 weeks to 4 weeks

Cheese, soft such as brie, bel paese, goat

In the freezer6 months
Unopened · in the fridge1 week to 2 weeks

From KeepsUntilWhere these numbers come fromThe USDA source, the parse rules and what this site cannot tell you

Can you freeze cheese?

Yes. The USDA gives cheese (hard such as cheddar, swiss, block parmesan) 6 months in the freezer from the day you buy it, and held at 0 °F food stays safe beyond that: the figure is about quality. It advises against freezing cheese (parmesan; shredded or grated) or cheese (processed slices). Dairy can separate or turn grainy once thawed, so frozen it is better cooked with than eaten as it was.

How to tell if cheese has gone bad

Go by the date first: cheese keeps 3–4 weeks in the fridge once opened. Sour or off smell, lumps in milk or cream, and mold mean it goes out. On hard cheese, cut away 1 inch around a moldy spot; soft cheese with mold goes out whole.

Sources: USDA FSIS: the danger zone USDA FSIS: freezing and food safety USDA FSIS: molds on food FDA: are you storing food safely FoodSafety.gov: the FoodKeeper app.

Is it still safe to eat, or just past its best?

The answer at the top of this page reads 3 weeks to 4 weeks in the fridge once opened. What decides that is the food and not the shelf the source files it on: it is an animal food, or made with one. Past it, it is not safe to eat: throw it out without tasting, because bacteria build up while food still looks and smells fine.

The figures in the freezer and in the fridge here are a quality window. The same page carries windows of more than one kind, so which sentence applies depends on which row you are reading, not on the food.

It is past the date. Now what?

Say the calculator above puts it past its 3 weeks to 4 weeks in the fridge once opened window, or the container sat out on the counter overnight. Throw the container out without tasting it, and count any hours it already spent out of the refrigerator as part of that window rather than on top of it.

The USDA's limit for perishable food standing at room temperature is 2 hours, or 1 hour when the kitchen is above 90 °F, and that clock runs whatever the storage figure says. Freezing stops the clock but does not turn it back: food already past its window is not rescued by putting it in the freezer. The whole rule, including the cases the source does not cover, is set out under what to do when the date has passed.

Items that behave the same way

Every one of the 6 nearest items keeps the same or less, 5 weeks to 6 months against the 6 months of Cheese, hard such as cheddar, swiss, block parmesan, which makes it the durable end of the cluster.

Where these numbers come from

Every storage time on this page is the USDA’s own published figure from the FoodKeeper data, one of the 9 it keeps per food, reproduced unchanged and never an estimate of ours. Where the USDA lists several kinds under one name, each kind keeps its own windows, and the page names the kind its answer is for. The dates and multipliers are ours, computed from those ranges.

Source: USDA FoodKeeper, retrieved 1 September 2026. Found a figure that does not match the source? Tell us on the contact page. How the site is built is on the method page.

Comparisons and the place in the category are computed for Cheese, hard such as cheddar, swiss, block parmesan, which is the kind the plain name means here, chosen kind by kind rather than by the order the source happens to list them in.

Also searched as: swiss cheese

USDA index terms: bel paese, brie, cheddar, goat, grated, mozzarella, parmesan, processed slices, shredded, slice, slices, swiss

KeepsUntil is an independent reference built on public USDA data. It is not affiliated with, endorsed by, or connected to the U.S. Department of Agriculture or the Food and Drug Administration. Whether a given window is a safety limit or a quality window is stated on the page that prints it.