As Rik Shaw says, you need to do a few test runs on that stuff. From experience I have found that one sample is never enough to be sure,you must take several samples. The downside is that by the time you have reached a verdict,there,s nothing left for cooking,but if you,re still standing,then it must be OK.
I have carried out this test many times,and it has never failed,but cannot say the same for the cooking !
PS I found a Christmas pud in my freezer,during a recent defrost,been in there for the last two years,never tasted better ! So,be brave !