I buy it in the 8oz bottle. I keep a 2oz. bottle on my bench and store the 8oz in the freezer then just fill the small shop bottle as needed. I have never had it go bad this way. If it starts to get that milkey look I don't use it. I live in a desert so there isn't much moisture in the air so even my opened shop bottle never seems to go bad or slow down. When I lived in the mountains I had one bottle cure completely while sitting in my shop so I started freezing it.