Going back to work in 2 months. Aiming to express so that DS can have one expressed feed a day. I am not that great at expressing so I don't want to express loads and find it is unusable. He is not that great with bottles so I can't tell whether him refusing it is a milk problem, or a bottle problem, or something else. Is there another way to tell high lipase apart from baby refusal?
Have you tasted it? Probably the fail safe way to know if it tastes bad. I tried a small spoonful of my frozen breast milk when my daughter refused it and despite having followed all the guidance about expressing, freezing and thawing it tasted soooooo grim. No unpleasant smell at all but tasted utterly horrific! I've since tried freezing a couple more batches and it's all horrible.
Easiest way to find out would be express a small amount freeze it, defrost it and taste it. High lipase resulting in unpalatable milk is often described as tasting soapy, like sour milk or even fishy!
Even if you do discover you have high lipase levels in your milk it doesn't mean it won't be possible to express and freeze your milk. All you have to do is scald the milk before freezing and it should be fine.
Basically, lipase affected milk is minging. I had problems with dd1 refusing bm expressed more than 24 hours previous. I tasted some (quite by accident, had dropped a bit on my wrist to check temp, no muslin to wipe so I licked it off) it tasted like washing up liquid with a hint of haddock. There is no mistaking it and no wonder babies won't drink it!