Thai curry paste can go bad once the jar has been opened or if has been kept past its expiration date. Each Thai curry paste brand will have a recommended amount of time that can be kept after it has been opened. Most Thai curry paste mixes will stay good in the fridge for up to 4 weeks once opened if stored correctly.
Thai curry paste is made up of a range of spices and oils which can separate and lose their flavor once opened. When the paste is exposed to air it can grow bacteria and mold.
We use Thai curry paste all the time in our house so keeping track of when it is opened is important. We are using a jar each week so we are usually using them within 3-4 days.
How to know if Thai curry paste has gone bad
Here are some things to look out for to tell that your Thai curry paste has gone bad.
Thai curry paste can be kept unopened in the cupboard for 1+ years up to the expiration date.
Smells
Thai curry paste will not smell like delicious spices and oils anymore and can have a rancid or vinegar smell. The spices can start to ferment and if bacteria and mold grows, they can release gases which tell you the paste has gone bad.
Thai curry paste that smells bad should not be eaten, it will taste terrible and poses a food safety problem.
Mold
Thai curry that has gone bad can grow white or blue mold which appears on the surface of the paste. This mold growth is unsafe to eat and will taste bitter.
Separation
Another way to tell that Thai curry paste has gone bad is when the spices separate from the oil. While this does happen to a small degree once you open the jar, a paste that has gone bad will look very oily on the top.
The oils will seep out of the spices and sit as a green or red puddle on the top. A small amount is fine but if your jar has been open for longer than a week it might have gone bad and should not be eaten.
Days in the fridge
Knowing how long your jar of curry paste has been in the fridge is important as this will be the key to knowing when it is time to say goodbye and start with a new one.
Bacteria and mold can be invisible, it is only once they grow to large colonies that we can see them. Small amounts of invisible bacteria could also be hiding in paste that has been in the fridge a long time even if you can’t see it.
The safest method is to date the jar when you open it and finish it before the recommended time, for the curry paste I use, that is 4 weeks.
How to keep Thai curry paste for longer
There are some ways to keep curry paste for longer unopened in the cupboard or opened in the fridge. Here are my favorite tips to stop curry paste from going bad.
Keep it in the fridge
Once you open a Thai curry paste jar it is important to keep it in the fridge. Close the lid on tightly and place it near the back of the fridge. This is where it will stay coldest and be less effected by the loss of cook air as the door of the fridge is opened.
Write the date on the jar when you open it and place it in the fridge so you know when it was opened.
This simple hack will help you to immediately calculate how long it has been in there and if it is still good to eat.
Mix it once you open it
Thai curry paste that has been in the fridge for 3-4 days will release a small amount of oil from the paste. I always notice about half a teaspoon of oil sitting on the top of my Thai green curry paste in the fridge. For small amounts of oil, give it a mix before using it to incorporate it.
The oil on the top of the paste is fine to leave there while it is in the fridge. The paste will coat your food better if it is mixed together before using, particularly if you are pre-coating meat in the paste before cooking.
Only keep one of each type of paste in the fridge
The easy way not to get confused about which jar of Thai curry paste to use first is to only open 1 of each paste at a time. I have definitely made the mistake of opening more than one jar of Thai green curry paste and found myself digging through the back of the fridge to find out which one I opened first.
Remember to check your fridge before you open another jar to make sure you don’t waste an already opened paste.
Store in a dark, dry cupboard when before opening
Unopened Thai curry paste they will keep in good condition in a dry, dark cook cupboard. The less light the paste is exposed to the more the spices will hold their flavor. Cupboards or shelves that get sunlight can heat up and cause the paste to lose its flavor.
If you notice any damage to the jar, lid or seal you should not use the paste. For jars with a pop top lid, make sure you listen for the pop when you open it to make sure the seal was closed.
This will give you the most delicious curry paste possible without the risk of air entering the jar and turning it bad.
How to keep track of how long Thai curry paste has been opened
Keeping track of how long Thai curry paste has been open in its jar in the fridge is as easy as writing the date on the side of the jar. Use a sharpie and write the current date so you can quickly see when you put it in there.
This is the easiest way to avoid using an old jar of paste that could be bad. Always check and smell the paste before using it to make sure it looks clean and smells delicious.
Does Thai Curry Paste Go Bad? | Summary
Thai curry paste will go bad after opening as the air can reach the paste. There is the chance that bacteria or mold could grow on the surface of the paste which will smell horrible and is bad to eat.
I like to buy small jars of curry paste so I can use them up in 2-3 weeks and they still taste fresh and delicious each time.
Happy cooking.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.