If you're really neurotic about it and you can't brew the batch in the near future there are several things you can do.
- You can freeze it, just be sure to seal it inside something first. This will also kill any bugs (literally bugs, not bacteria) that may be in your base grain such as Weevils for example.
- You can dry it out more fully in the oven. This is still a risk and there is a good chance it'll reduce your enzyme potential but if you do it well you shouldn't have issue. It's still a risk as you have no way to tell the moisture content so using it within the next couple months isn't a bad idea in any event and you should probably give it a week or two before use after drying in the oven.
If you dry it in the oven put it in a somewhat shallow evenly spread out layer on a cookie sheet no deeper than the depth of the cookie sheet used. Put it in an oven on the lowest setting you've got. Ideally 150 if you've got it but if you're limited to 170 or 200, you can usually leave the door cracked open and lose 15-30% of the selected temperature (dropping you down to ~136-185 degrees). A fan is helpful as well. The downside to this is the higher the temp the more enzymes you're going to kill, the upside is it'll give you a unique flavor to your kit and possibly even make it a tiny bit sweeter depending on how much water the grains actually absorbed. The guy over at
Barleypop heavily advocates a week or two rest afterwards but I'll admit I don't always abide by that as I like the taste of a fresh convection baked amber grain in my beer.