Brewing an altbier at home
Altbier is the traditional copper ale of Düsseldorf. It uses ale yeast fermented cool, then weeks of cold conditioning. The result is clean like a lager, with firm bitterness and a rich malt base.
Alt means old, as in older than lager
Alt means old in German. The name refers to the older, top-fermenting brewing method that survived in Düsseldorf while most of Germany turned to lager. Typical numbers: original gravity 1.044 to 1.052, about 4.3 to 5.5% ABV, 25 to 50 IBU and a copper to brown colour around 9 to 17 SRM.
The flavour is bready, toasty malt with firm bitterness and a clean, dry finish. Fruit esters should be low. It is closely related to kölsch, Cologne's pale cousin. It uses a similar cool fermentation.
A grist led by Munich malt
For 20 litres at about 1.049:
- 2.5 kg pilsner malt (55%)
- 1.6 kg Munich malt (35%)
- 0.25 kg CARAMUNICH type crystal malt (5%)
- 0.15 kg melanoidin or aromatic malt (3%)
- 0.08 kg dehusked black malt (2%)
- Mash at 65 to 66 °C for 60 minutes
The dehusked black malt adds colour without harsh roast. Some recipes use a step mash or a single decoction for deeper malt flavour. A single infusion with melanoidin malt gets most of the way at home.
Firm bitterness from German hops
Altbier can be surprisingly bitter for a malty beer. Aim for about 35 to 40 IBU. With a 4% alpha German hop like Spalt or Tettnang, that is about 60 to 70 g at 60 minutes for 20 litres. A small addition of 15 g at 15 minutes adds a little spice. Keep late hops restrained. Altbier is about balance and bitterness, not hop aroma.
Low alpha German hops mean more hop matter in the kettle. Allow for some extra loss and a slightly larger trub pile.
Cool ale fermentation
Use a German ale or altbier strain. Pitch at 13 to 15 °C and hold there for about a week. Cool fermentation keeps esters low and gives the clean profile that defines the style. Then let the temperature rise to 17 to 18 °C for two or three days to finish and clean up diacetyl.
In an Indian home this almost always needs a fridge or freezer with a temperature controller. A water bath at 15 °C in summer means changing ice every few hours, which is tiring. Our guide to fermentation temperature control covers the cheaper set-ups.
Cold conditioning is not optional
After fermentation, cold condition the beer at 0 to 2 °C for three to four weeks. This is what turns a cool-fermented ale into an altbier. Yeast drops out, sulphur fades and the malt and bitterness integrate. Rushing this step gives a beer that tastes rough and yeasty.
Carbonate to about 2.5 volumes. Serve at 8 to 10 °C in a small straight glass.
If you can only fit one fermenter in the fridge, plan around it. Brew the altbier when nothing else needs the cold space for six weeks. A spare chest freezer with a controller is the single most useful upgrade for German styles in India, since it handles fermentation at 14 °C and conditioning near 0 °C in the same box. Bottle conditioning works too: prime with about 6 g of sugar per litre, leave the bottles at room temperature for two weeks, then move them to the fridge for another two or three. The beer clears and smooths in the bottle, though more slowly than in a keg.
Water and mash pH
Düsseldorf water is moderately hard, which supports the darker malts. If you use RO or soft water, add about 3 g of calcium chloride and 2 g of gypsum to the 20 litres. That gives calcium for yeast and a balanced flavour. If you use hard borewell water, check alkalinity before mashing. Aim for mash pH 5.3 to 5.4.
What makes an alt taste right
A good altbier is clean, malty and bitter, with a dry finish that makes the next sip appealing. Fruity esters mean the fermentation ran warm. Harsh roast means too much black malt or a husked version. Sweetness means too much crystal or a hot mash. Judging that balance in a glass is a big part of style training.
Altbier is also a good food beer. Its bitterness cuts through fried snacks and its toasted malt suits grilled meat, sausages and mutton seekh kebabs. Serve it in small glasses and pour fresh ones rather than letting a large glass warm up.
A steady 14 °C is the entry ticket
Set your fridge controller to 14 °C and log the temperature of a bucket of water for three days. If it holds within a degree, you can brew an altbier this month.
Common questions
Is altbier an ale or a lager?
It is an ale, brewed with top-fermenting yeast, but fermented cool and cold conditioned like a lager.
How long should altbier be cold conditioned?
Around three to four weeks near 0 to 2 °C.
How bitter should altbier be?
Firmly bitter for a malty beer, usually 25 to 50 IBU, with about 35 to 40 a good homebrew target.
