Shelf life of dog treats 4-6 months, please help!

We have a peanut butter, oatmeal and gluten free flour dog treat that is all human grade and we want to sell these treats at an upcoming trade show.

We are nervous about their shelf life. During our tests, sometimes they lasted for several months with no mold but recently I saw mold after one month.

The recipe calls for 1/2 cup water and I have reduced this to 1/4 cup and 1/4 cup of honey. They do turn out like little cookies and are somewhat crumbly if you apply pressure.

Please help us determine which preservative would work best and how much to put in. Also, how to make the cookies a bit harder. Thank you so much!!

Chef's Answer ~ One possible explanation for the different spoiling times is the ambient temperature where the treat was kept. The warmer and moister the air around the treat, the quicker it will spoil.

A great preservative can be found at K9 Cakery.com. They have all kinds of great tools and dog treat decorations to make homemade dog treats.

As far as the crumbly texture of your cookies, one thing to double check is how you are measuring your flour. For baked goods, it's best to sift the flour first, or what I do is lightly spoon (and shake) the flour into the measuring cup, overflow it slightly, then level off the excess with the back of a butter knife.

I hope this helps. Happy Dog Treat Baking! :)