Hi and thanks for asking about "how to" with raw beef pancreas. We actually have a section on it on this page:
https://epi4dogs.com/enzymes-in-brief/
but i am also copying it for you here and this should answer all your questions.
FEEDING RAW PANCREAS: If you would like to try using raw pancreas; fresh beef, pork or lamb pancreas are recommended. Raw BEEF Pancreas is available for purchase in the USA at
http://www.hare-today.com/ or
http://www.greentripe.com/ . or Sirius Natural Pet Foods . There is also an amazing selection of raw pancreas at:
https://www.mypetcarnivore.com/ . If you are in the U.K. you can look into
http://rawtogo.co.uk/ .
One to three or four ounces of raw pancreas can replace one teaspoon of pancreatic extract. Raw pancreas may be frozen in cubes for future use and thawed naturally, but never heat on the stove or in the microwave.
First puree the raw pancreas and (for your convenience) then freeze it in 1 ounce packets (or an ice try should work). Once you figure out how many ounces of raw pancreas your dog responds best to per 1 cup of food....(whether it is 1, 2 ,3 or 4 ounces of the raw pancreas)..... let the proper amount of frozen raw pureed pancreas thaw naturally.... and mix in with the food. It appears to usually work best when allowed to "incubate"... we suggest 15 - 20 minutes... but some do fine with less time, and some seem to need a few minutes more. IN the beginning there will be some trial and error until you figure out what works best for your dog.
If possible beef or lamb raw pancreas is recommended over pork pancreas because of the “possibility” of the transmission of pseudorabies, although rare.
http://en.wikipedia.org/wiki/Pseudorabies
Also… raw pancreas is not all the same. Each and every gland has a different potency of enzymes. This is not just species to species. The potency can vary from one farm animal to another farm animal as well. If you use 1 ounce of raw pancreas with the batch you are currently using the next batch may need to be tweaked. Fresh pancreas has a shelf life (in the freezer) of up to 3 months.
Adding enzymes to a raw fed meal:
Since raw food is harder to measure by the cup since the densities of different meat/bones will require different levels of enzymes, it is easiest to go by weight rather than amount! ” To add the enzymes, you can either puree a portion of the raw meat and add the enzymes to that pureed slurry and pour over the remainder of the raw food, let sit for 20 minutes and serve, or you can add the enzymes to something like yogurt/kefir and either add to the food as mentioned above, or serve the enzymed slurry first ahead of the meal. Try both to see which works best with your EPI dog. (Thank you Cait for these great suggestions!)