Quick Answer
Lemon bars can be safely left at room temperature for 2-3 hours. After that, they should be refrigerated to prevent bacterial growth. Refrigerated lemon bars will last 3-5 days. For longer storage, lemon bars can be frozen for 2-3 months.
How Long Can Lemon Bars Be Left at Room Temperature?
Freshly baked lemon bars can be left at room temperature for 2-3 hours before refrigeration is needed. During this time, the bars will be safe to eat. After sitting out for more than 2-3 hours, bacteria can begin to multiply quickly in the cream cheese, eggs, and dairy in the lemon curd filling. For food safety, it’s important to refrigerate the bars within that 2-3 hour window.
Here are some general guidelines for how long lemon bars can be left unrefrigerated:
- 1-2 hours: Best quality and safety
- 2-3 hours: Still safe to eat, but quality starts to decline
- Over 3 hours: Increased risk of foodborne illness, bars will start deteriorating
The temperature of the room also plays a role. The warmer the room, the faster bacteria can multiply. On a hot summer day, aim to refrigerate lemon bars after no more than 1-2 hours at room temp.
How to Tell if Lemon Bars Are Bad at Room Temperature
As lemon bars sit out at room temperature for too long, signs of spoilage will become apparent. Here are some ways to tell if your lemon bars have been left out too long and may be unsafe to eat:
- Drying out – The lemon curd filling and crust will dry out.
- Cracking – The surface may crack or weep liquid.
- Mold growth – You may see fuzzy mold growing, especially on the crust.
- Off smell – An unpleasant or sour milk smell indicates spoilage.
- Off flavor – The filling will taste sour or bitter if bacteria has multiplied.
- Change in texture – The bars will become soft or mushy.
Trust your senses – if the bars look, smell or taste off after being left out, it’s best to throw them away. Don’t take risks with foodborne illness.
How Long Do Lemon Bars Last in the Fridge?
Properly stored in the refrigerator, lemon bars will last 3-5 days. The bars should be covered or in an airtight container in the fridge. This prevents them from picking up odors from other foods and avoids drying out.
Make sure your fridge temperature is set below 40°F. The colder environment keeps bacteria growth in check and extends the shelf life.
Look for signs of spoilage before eating refrigerated bars, like mold, off-smells, drying or cracking. Discard if the quality has deteriorated.
For maximum freshness, aim to eat refrigerated lemon bars within 3 days. The bars will start to lose their texture and flavor after that.
Can Lemon Bars Be Frozen?
Freezing is a great option for storing lemon bars long-term. Properly frozen lemon bars will keep for 2-3 months in the freezer.
To freeze lemon bars:
- Let the freshly baked bars cool completely first.
- Cut into portions if freezing a whole pan.
- Place bars in a freezer-safe container or bag.
- Seal tightly to prevent freezer burn.
- Label container with name and freeze-by date (2-3 months).
- Freeze for up to 3 months.
Thaw frozen lemon bars overnight in the refrigerator. Let them come to room temperature before serving.
Freezing prevents bacterial growth and slows down chemical reactions that cause food to deteriorate. The bars may lose a bit of texture, but will still taste great after freezing.
Can You Refrigerate or Freeze Lemon Bar Batter?
Raw lemon bar batter can also be refrigerated or frozen:
Refrigerating batter:
Cover and refrigerate batter for up to 3 days before baking. Whisk before using to reincorporate ingredients. Add a few extra minutes to the bake time.
Freezing batter:
Pour batter into a freezer-safe container, sealing tightly. Freeze for up to 3 months. Thaw overnight in fridge before baking. This may affect the texture, so add extra baking time.
Refrigerating or freezing the batter gives you the flexibility to bake fresh lemon bars over several days, instead of all at once.
How to Thaw Frozen Lemon Bars
To safely thaw frozen lemon bars:
- Place the frozen bars in the refrigerator overnight. Allow 8-12 hours for thawing.
- Transfer to the counter about an hour before serving. This allows them to come to room temperature.
- Check that bars are completely thawed before serving. The filling should not be icy or frozen.
- Do not try to thaw at room temperature or in warm water. This allows bacteria to multiply.
- Consume within 3-5 days of thawing.
Refrigerator thawing keeps the bars out of the temperature danger zone while defrosting. Bars thawed on the counter may have bacteria growth.
For quicker thawing, you can slice frozen bars before refrigerating overnight. Cutting into smaller pieces helps them thaw faster.
Reheating Thawed Lemon Bars
To restore crispness and flavor, thawed lemon bars can be briefly reheated in the oven:
- Preheat oven to 350 ̊F.
- Place bars on a baking sheet.
- Heat for 5-10 minutes, watching closely to avoid burning.
- Remove once crust is crispy and filling is warm.
- Let cool slightly before serving.
Microwaving is not recommended, as it can make the crust soggy.
Only reheat thawed lemon bars once. Reheating more than once increases the risk of foodborne illness. Discard any uneaten reheated bars.
Storing Lemon Bars
Follow these storage guidelines for fresh lemon bars:
At room temperature: Eat within 2-3 hours of baking.
Refrigerator: Store in airtight container for 3-5 days.
Freezer: Seal in freezer bag or container for 2-3 months. Thaw overnight in fridge before serving.
Batter: Refrigerate for up to 3 days or freeze for up to 3 months before baking.
Proper storage prevents drying out, quality loss and dangerous bacterial growth. Discard bars if moldy or smell or taste off. Enjoy your lemon bars fresh or store them safely using these guidelines.
FAQs
Can you get food poisoning from lemon bars?
Yes, you can get food poisoning from eating lemon bars that have been left out too long at room temperature. The dairy and eggs in the filling can grow dangerous bacteria after 2-3 hours unrefrigerated. Eating contaminated bars can cause symptoms like nausea, vomiting, stomach cramps, and diarrhea.
Do lemon bars need to be refrigerated?
Yes, lemon bars do need to be refrigerated for food safety. After baking, lemon bars should be refrigerated within 2-3 hours. Refrigeration prevents bacterial growth. Refrigerated lemon bars can be stored for 3-5 days.
Can you leave lemon bars out overnight?
No, do not leave lemon bars out overnight. The bars must be refrigerated within 2-3 hours of baking. Leaving them at room temperature overnight poses a high risk of food poisoning from bacterial growth.
How can you tell if lemon bars are bad?
Signs that lemon bars have gone bad include mold growth, cracking, weeping liquid, an off smell or flavor, drying out, or a change in texture. Discard bars that display any sign of spoilage.
Can you freeze lemon bars?
Yes, lemon bars freeze very well. To freeze, let bars cool completely, wrap tightly in plastic, and freeze for up to 3 months. Thaw refrigerated overnight before serving. Frozen storage stops bacteria growth and preserves freshness.
Conclusion
Lemon bars can only be left at room temperature for a maximum of 2-3 hours for safety and quality. Refrigerating extends the shelf life to 3-5 days. For long term storage, freeze bars for 2-3 months. Keep an eye out for signs of spoilage and discard bars that look or smell off. Following proper storage methods will keep your lemon bars fresh and prevent foodborne illness.
