Well in my attempt to brew a gluten free beer I have gathered my ingredients, Certified oat flakes, quinoa, kasha, and some sweet rice, along with my hops and dry yeast. I have about 2 # of each grain and I want to make a 3 gallon batch to start with. II will also add frozen sweet cherries to the primary to add flavor. My question is how much grain to add to get a abv of 4 to 5%. I can use any combination of the above grains or just 1. Help me with a recipe.
What you are asking is probably the most advanced brewing procedure there is without involving yeast culturing or water chemistry.
You want to do an all-grain, 100% adjunct, gluten-free beer with 4 different types of grain and then do a fermentation over fruit. First, may I just say that unless you have a lot of experience under your belt, you should perhaps reconsider your fermentables.
In any case, just to help, here is how you can figure out sugar content of various grains and what it would contribute to your beer.
1lb of Sugar has about 48 pts of Sugar in it. 1lb of Complex Carbs has about 70% of that, or 33.6pts. This is in 1 gal of water, so if you want to make 3gal of something, divide by 3. This is also to say 1.048 for sugar, and 1.0336 for carbs. You need to find the nutritional content of whatever you are adding and use this data to approximate total potential sugar content. Make sure the fruit is also part of this analysis, Fructose counts as sugar too.
Then, you need to decide what your efficiency will be. It should be near 100% on a bag of sugar, slightly lower on mashed fruit, lower on whole fruit, lower still on well-crushed grain with great enzymes to convert into sugar (around 80% here), lower still as you lose crush or enzymes (70%), lower still as you use weird adjuncts (60%), lower still as you leave out some of the enzymes (only alpha, 50%).
Anyway, you get the idea. Fairly complicated but I hope that helped.