Hi Cheesemkr,
To find out if they are still "good", try this. Buy a 1 litre box of "UHT" skim milk. This isn't much good for making hard cheese, but it's great for making "culture cubes". It's also sterile. So, open it, and put a few grains of your culture in it. If it's a meso culture, just close the UHT loosely so there's air exchange, and leave it out at room temp (22 C type thing) for 24 hours. For a thermo, put it in a warmer spot (I put it in the closet on top of our hot water cyllendar). If it's good, then after 24 hours it should have thickened into a yogurt like consistency. You can then pour this into ice cube trays (you'll get about 40 cubes) and freeze them. I then keep them in zip lock type freezer bags. When you go to make a cheese, you can add these cubes instead (I use 2 or 3 in a 10 litre make).
Anyway, I've been doing this for over a year now, and have only had to make my second batch of ice cubes (but, I've got both meso and thermo cubes, and a I also made a batch of cubes from 600 ml of buttermilk). The cultures were well over a year by then. It's possible, of course, for some of the strains to die off while other bits are still active, so the resulting cubes might not have the same mixture ratio of bacteri.
But, at least this will let you know if they are still working. I suspect they are probably fine if they were stored in the freezer the whole time.
- Jeff
