gloopy almond milk

[headdress]

Each time I make almond milk after a day or so it goes gloopy. I started of putting it in a glass bottle. I thought maybe it was not sealing well enough so I bought a kilner jar that seals completely. Still no joy. Please tell me where I am going wrong if anyone knows?!

I blend the almonds after soaking with a couple of dates and s pinch of salt. I then put it in a nutmylk bag bought from Wholefoods and squeeze out the milk.