What will the fava bean look like when it is mature?
The pods become large and the beans will be FULL feeling inside and firm. The bean’s pod may begin to darken slightly    Main thing to watch for is aphids.  Spray weekly with parsley tea (big hand full of dried parsley steeped in 1 gallon boiling water for half hour). Let cool and spray plants with this.
 Any special instructions on growing?
Some plants become tall and need stacked. Others are shorter. It is still helpful to hill soil around them for support. Watch for aphids!!
What then? Pick and let dry? Do they have to dry? Can dry beans be kept in freezer until ready to sprout at a later time, like in winter?
The green pods are the most useful part of the plant. Juice them at any size (as long as they are pretty…not black spotted).  Juice and freeze juice or make fava chips by adding ground flax seed. Salt to taste and dry blobs in dehydrator. These really work good for l-dopa.
You can also just drink the juice or freeze in ice cube trays perhaps in whatever dose size your body needs. Everyone is different!!
How do you sprout them?
Soak beans overnight in a large stainless steel or glass bowl. Then, rinse three times a day for 3 whole days. Peel, rinse and steam them for 8 minutes. They are then ready to freeze or stir fry with garlic & onions or make into Fava Sprout Balls :: Mash steamed beans: Add peanut butter and ground oatmeal.
Look up : “No Bake Cookies” on internet and revise as needed. People only have to find sproutable organic fava beans at the health food store to make these They are a very good source of l-dopa.
I really prefer using sprouts instead of the tincture of bean sprouts because there is not a great deal of l- dopa when it is completed. Thus for the tincture I prefer using the fava plant tops.
About how many beans make how much tincture?
Use 2 cups of steamed, mashed sprouts to 1 C Brandy
Will the tincture “go bad†– thinking about how much can be made ahead.
This I cannot answer…haven’t had it for more than a month at a time.  The fava tops tincture has lasted a year (haven’t had it any longer).
In my research I found a Fava called “Ianto’s Return†(sometimes Ianto’s, or sometimes Lanto’s) “Originally introduced by Alan Kapuler of Peace Seeds. A large-seeded Guatemalan variety that reaches 6 feet tall. The bright yellow seeds are reputed to contain elevated levels of dopamine.†Is this the variety that you grow?
I have never had this variety . I buy generic, organic fava beans from the health food store in 20 lb bags.
I do highly recommend a G6pd blood test for anyone planning to try using favas for medicine.
I also recommend making your own fermented papaya. It helps symptoms amazingly well, even dried store papaya is helping a friend who is going natural like me. My friend also uses mucuna capsules 2AM   and one  1 PM and fava tops tincture in between and she is doing wonderfully.
May God Bless You and guide you in your quest for optimum good health.
Aunt Bean