Marking Deer Sausage in the Smoker

[Deer S]

We are making several types of deer sausage at the same time. When they are in the smokers how can you tell one recipe from the other? They all look the same in the casings. We used to have a system but with different people removing the meat from the smoker we have had the batches get mixed up. We are making several small test batches with recipe variations and want to do taste testing before sausage fest. Any ideas would be appreciated.