Hi Dasorge,
I can't really offer any suggestions as to the specific ratio of each grain (e.g. how much corn compared to how much rye, and how much barley malt). That's going to depend on what you're trying to accomplish WRT flavor. But there are some techniques and guidelines you can use to determine things like your OG and the amount of malt that you will need.
The first thing you should do is get a copy of John Palmers, "How to Brew" and read it cover-to-cover. Or read the online version at:
http://www.howtobrew.com/sitemap.html It's a fairly quick read and the time you invest in reading it will pay you back in spades. The book has more illustrations and it's easier to navigate IMO.
In any case, the system Palmer describes is based on "points per pound per gallon" or simply PPG. A "point" being equivalent to a specific gravity increment of 0.001. For example, a grain rated at 10 PPG would yield a gravity of 1.010 if you used one pound per gallon. A grain (or adjunct) rated at 20 PPG would yield a gravity of 1.020 if you used one pound per gallon ... and so on. You can find the PPG for several common grains/adjuncts at:
http://www.howtobrew.com...tion2/chapter12-4-1.html So, let's say you take advantage of ohyeah's experience and and advice, and shoot for a 10 gallon wort at around 6% abv. That's an OG of about 1.040 ... which means you need 40 PPG. Since you have 10 gallons, you need 40 points x 10 gallons = 400 total points. Once you have the total points you can adjust your grain bill as you see fit. But let's use your original ratios of 80 parts corn, 12 parts rye and 8 parts barley malt (I'll use the "typical" ppg for flaked corn, rye and 6-row barley)
0.80 x 33 = 26.40 (Corn at 33 ppg)
0.12 x 25 = 3.00 (Rye at 25 ppg)
0.08 x 30 = 2.40 (6-row barley malt)
-------------------------------------------------
Total = 31.80 ppg
Now you know how many points you get from a single pound of the mixed grains at the given ratios.
To get your total grain weight: 400 total points / 31.80 ppg = 12.57 (or about 12.5 pounds of grain). You end up with a grain bill of:
Corn: 0.80 x 12.5 = 10 pounds
Rye: 0.12 x 12.5 = 1.5 pounds
Malt: 0.08 x 12.5 = 1.0 pounds
Using that grain bill should produce a 10 gal. wort with an OG of 1.040 (or 6% PA). Plus or minus any math errors.
At this point we're still not done though. If you plan on mashing (which you will have to do if you don't add any sugar), you're going to need some enzymes. This will normally come from your malt. But you have to make sure your grain bill has an adequate "diastatic power" to convert all those starches into sugars. The diastatic power (DP) is basically the "enzyme strength" of malt. It's given as "degrees Lintner" (°L). A malt with a DP of 35 °L is supposed to have sufficient power to convert itself. So the minimum average DP would be about 35 °L. However, I've found several references that recommend an average diastatic power somewhere in the neighborhood of 40 - 50 °L.
Again if we look at your grain bill we can calculate the average DP. Let's say you use Briess 6-row with a DP of 160 and unmalted corn and rye. You would have an average DP of 160 / 12.5 = 12.8, so you wouldn't have enough enzymes to convert all of your starches. This leaves you with a few choices:
[LIST=1]
Adjust your grain bill to get the needed enzymes (i.e. - add malt, reduce corn)
Use powdered enzymes
Just make a sugarhead and forget about mashing altogether.
[/LIST]
All of this is why using a tried and true recipe is always a good idea. You'll know that all the details have been worked out for you, you'll know that others have tried it (and that it is in fact, "true"), and you can ask for help/suggestions from those people.
Anyway, sorry for the long post. I figured it might be useful in the event anyone is suffering from insomnia.
Regards,
--JB
