Brewing a Czech pale lager at home

Richer and rounder than German pils

Czech premium pale lager is golden and full of soft bready malt, with a long, clean bitterness and spicy Saaz aroma. Typical numbers: original gravity 1.044 to 1.060, about 4.2 to 5.8% ABV, 30 to 45 IBU and a deep gold colour around 3.5 to 6 SRM. Final gravity runs slightly higher than a German pils, which gives the rounder body.

A small amount of diacetyl is accepted in the Czech style, unlike most lagers. That does not mean butter should be obvious. It means a faint richness is not a fault.

Very soft water is the foundation

Plzeň water is famously soft, very low in minerals. That softness lets a lot of Saaz bitterness taste smooth rather than harsh. Most Indian borewell water is far harder. Municipal water varies by city.

The simplest route is RO water or packaged drinking water with very little added. For 20 litres, about 1 g of calcium chloride is enough for yeast health. Add acidulated malt or a little lactic acid to bring mash pH down to 5.2 to 5.4. Our guide to rice lager covers the same water approach.

A pilsner malt grist

For 20 litres at about 1.050:

• 4.4 kg Bohemian or other pilsner malt (92%)
• 0.25 kg light crystal malt such as CARAHELL (5%)
• 0.15 kg acidulated malt (3%)

Czech brewers traditionally use decoction mashing, which builds the deep malt flavour. A single decoction is achievable at home. A step mash at 52 °C, 63 °C and 72 °C gets close. A single infusion at 65 °C with good pilsner malt still makes a very good beer.

Boil 90 minutes to drive off DMS, which pilsner malt produces more of than pale ale malt.

Pilsner malt from different maltsters varies more than most homebrewers expect. Floor-malted Bohemian malt tastes richer and more bready than a standard continental pilsner malt. If you can only get one kind, brew with it twice before you change anything else in the recipe. That way you learn what the malt gives before you start blaming the yeast or the water.

Saaz hops in generous amounts

Saaz is the classic hop: low in alpha acid, around 3 to 4.5%, with spicy, herbal and floral aroma. For about 35 IBU in 20 litres with a 3.5% Saaz, you need roughly 60 g at 60 minutes, plus 30 g at 30 minutes and 30 g at 10 minutes. That is a lot of hop material for a pale beer. Expect a large trub pile and some extra wort loss.

Freshness matters. Saaz loses its character quickly when stored warm. Buy the most recent harvest you can find and keep it frozen.

Cold fermentation and a long lager

Pitch a Czech or other clean lager strain at 8 to 10 °C, with two sachets of dry yeast or a big starter for 20 litres. Ferment there for 10 to 14 days. Raise to 14 to 16 °C for a two to three day diacetyl rest, then drop slowly to 0 to 2 °C. Lager for four to six weeks or more.

This schedule needs a fridge or freezer with a controller. Our guide to brewing a lager at home covers practical set-ups for Indian homes.

Carbonation and pouring

Carbonate to about 2.4 to 2.5 volumes. Czech lager is often poured with a thick, wet head, sometimes almost entirely foam. That pour softens carbonation and lifts aroma. Serve at 6 to 8 °C.

Store finished beer cold. Pale lagers with delicate hops oxidise and lose freshness quickly in warm storage. In an Indian summer, a bottle left on a shelf can taste stale within weeks.

If you bottle, prime with about 6 g of sugar per litre and give the bottles two weeks at room temperature before chilling them for a few more weeks. Keg brewers have an easier time. A keg kept at 2 °C carbonates and lagers at once. You can sample the beer as it develops.

Faults to watch for

Harsh bitterness usually means hard water. DMS means a weak boil or slow cooling. Strong butter means the diacetyl rest was skipped or too short. Grassy notes mean old hops or too long a dry contact. Judging a slight diacetyl richness against a clear fault is a fine sensory line and one that style training covers in depth.

Test the water before the malt

Test your brewing water before you buy any malt. A cheap TDS meter or a water report from your municipality tells you how far you are from soft Plzeň water. If you read more than about 100 ppm, plan to brew with RO water.

Common questions

Why does Czech lager need soft water?

Soft water lets high Saaz bitterness taste smooth. Hard water makes it harsh.

Is diacetyl acceptable in Czech pale lager?

A faint richness is accepted in the style. Obvious butter is still a fault.

Do I need to decoction mash?

No. Decoction is traditional, but a step mash or single infusion with good pilsner malt works well at home.