Great at first, but seemed to expire - Review for John Allan’s Slickwater Pre-Shave Solution

This product was AMAZING at first. A little goes a long way. So long, that the bottle lasted a very long time. The only problem was that towards the end, the consistency seemed to change. Does it expire? I don't know. All I know is the last shave was not as good as the first and I used the same shaving cream and always fresh blades.