Technically, don't use it You opened it last year and haven't used it for at least six months. It's not sealed, so you don't have to look at the expiration date. I suggest you throw it away. For the sake of health, don't be careless
You can also check for yourself whether it has gone bad. Look at the color and taste.
Personal advice, don't use it. Time is too long. There are hidden dangers to health.