I designed this recipe based on Guidelines for brewing Altbier from a German brewing text book. This is an Alt that is very much in line with the average German commercial Alt. Though a large amount of Munich malt is used, it is a very well attenuated easy drinking dry beer dominated by hop bitterness without being being very bitter (compared to Pale Ales or even IPAs). The Carafa gives it just a hint of roast in the aroma and taste and most of the time you won't even know it's there. Though the used yeast doesn't flocculate well, the resulting beer is clear after finning with gelatin and bottle conditioning with a flocculant lager yeast.
Feel free to simplify the procedure if you don't want to bother with the single decoction or the priming with Kraeusen, otherwise give these advanced techniques a try.
I did not give specific weight amounts for the grains and hops. You can get them by using a brewing calculator and entering 89lb, 10lb and 1lb for the grain amounts, adjusting the final gravity to 11.5 *P (1.046 SG) by changing the efficiency or batch size and then scaling the recipe to the actual batch size and efficiency.
for brewers who build their own water
30L (assuming 25L (6.25 gal) pre-boil volume) reverse osmosis water +
0.8g NaCl (table salt)
0.6g MgSO4 (epsom salt)
1.8g NaHCO3 (baking soda)
4.0g CaCO3 (chalk)
(58mg/L Ca; 3mg/L Mg; 32mg/L Na; 10mg/L SO4; 21mg/L Cl; 150mg/L HCO3)
89% Weyermann Munich I (light Munich)
10% Weyermann CaraMunich I
1% Wyermann Carafa II special
Aim for a post boil gravity of 11.5 *P (1.046 SG)
German Spalter Hops to get to 27 IBU (Tinseth) at a 60 min boil time. Substitution with German Magnum possible, though the bitterness will not be as smooth.
Wyeast 1007, propagated to yield about 80 ml (~2.5 oz) for a 19 L (5 gal) batch.
protein rest : 54 *C (131 *F) for 20 min
saccrification rest : 65.5 *C (150 *F) for 45 min; water/grist ratio 3.5 - 4.0 l/kg (1.75 - 2 qt/lb)
mash-out : 76 *C (169 *F)
This is a fairly thin mash, but the water/girst ratio use is fairly standard in German brewing practice.
Add hops after 10 min boil and boil for another 60 min. Chill to pitching temperature of 17 *C (64 *F). Keep about 2L of the wort (freeze in soda bottle)
Ferment at 17 - 19 *C (63 - 67 *F) until fermentation is complete. Perform fast ferment test to determine limit of attenuation or use other means to ensure complete fermentation.
Once fermentation is complete cool the beer below 10 *C (50 *F) and add gelatin once beer is at that temperature. To fine with gelatin, dissolve 1/2 pk (3.5 g) of unflavored Knox gelatin in 100 ml (3 oz) of warm water. Add to fermenter when completely dissolved and swirl to distribute. This can be done in the primary fermenter or a secondary. Use secondary vessel if you plan to age the beer in it for more than 2 weeks.
One day before bottling, defrost the wort you kept, boil it, chill it and pitch a highly flocculant yeast. If you don't have a lager going at this time (like I usually have) use Wyeast 1056 or Nottingham Ale yeast. Let this start fermenting and gently add the fermenting starter w/o its sediment or Kraeusen to the bottling bucket. Add the beer and bottle.
(for 17L (4.5 gal) beer, you should need about 1.5 L (1.5 qt) Kraeusen for bottling. This assumes that the gravity of the Krauesen has not dropped below 9*P (1.040 SG) yet)
Keep the bottles at fermentation temp for about a week and the beer should be ready for drinking. Some age (2-4 weeks) will benefit it though.
You can also find this recipe on Brewer's Friend - Kaiser Alt