Ultra Low Carb Session Lager (44 L / 11.6 gal)

Can you brew a genuinely great lager that's ultra low in carbs and easy on the booze without making it taste crap? This recipe proves you can,  each pint comes in at around 100 calories, with an estimated 2.8 g of carbohydrates but it still packs flavour! By combining a highly fermentable mash schedule with dextrose and glucoamylase enzyme, this lager finishes incredibly dry while still delivering the crisp, refreshing character you'd expect from a classic session lager!

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Stats

• Style: Ultra Low Carb Session Lager
• ABV: 4.3%
• OG: 1.027 (measured 1.033)
• FG: 1.001 (measured 1.000)
• IBU: 13
• Colour: 3 EBC
• Carbonation: 2.4 vols CO₂
• Batch Size: 44 L (11.6 gal)
• Boil Time: 60 min
• Brewhouse Efficiency: 80%
• System: BrewZilla / RoboBrew 65L
• Carb calculator for finished beer

Ingredients

Grain Bill (4.3 kg / 9.5 lb total)

• 3.3 kg (7.3 lb) Craft Export Pilsner Malt — 76.7%
• 1 kg (2.2 lb) Corn Sugar (Dextrose) — 23.3%

Hops (76.4 g / 2.7 oz total)

Boil

• 19 g (0.67 oz) Pride of Ringwood @ 60 min — 13 IBU

Flameout

• 57.4 g (2.0 oz) Pride of Ringwood @ 0 min

Yeast

• 5.8 packs Fermentis SafLager S-189

Water Profile (Light Lager)

• Calcium (Ca): 23 ppm
• Magnesium (Mg): 5 ppm
• Sodium (Na): 15 ppm
• Chloride (Cl): 31 ppm
• Sulphate (SO₄): 32 ppm
• Bicarbonate (HCO₃): 57 ppm
• SO₄/Cl Ratio: 1.1
• Mash pH: 5.56
• Sparge pH: 5.30

Mash Additions

• 38.261 g Glucoamylase 400
• 1.148 g Gypsum
• 3.826 ml Phosphoric Acid (85%)

Sparge Additions

• 1.167 g Gypsum
• 1.721 ml Phosphoric Acid (85%)

Boil

• 1.531 g Whirlfloc @ 15 minutes

Mash Schedule

High Fermentability Mash

• 64 °C (147 °F) — 30 minutes (Beta Amylase Rest)
• 70 °C (158 °F) — 30 minutes (Alpha Amylase Rest)
• 77 °C (171 °F) — 10 minutes (Mash Out)

Mash Water: 34 L (9.0 gal)

Sparge Water: 20 L (5.3 gal)

Fermentation Schedule

• Primary: 20 °C (68 °F) for 14 days
• Carbonation: 2.4 vols CO₂

Step-by-Step Brewing Method

1. Mash In

Mash the pilsner malt in 34 L (9.0 gal) of water at 64 °C (147 °F). Add the glucoamylase enzyme during mash-in to help break down complex sugars into highly fermentable sugars. Hold for 30 minutes.

2. Alpha Rest

Raise the mash to 70 °C (158 °F) and hold for another 30 minutes to maximise conversion while maintaining a highly fermentable wort.

3. Mash Out & Sparge

Raise to 77 °C (171 °F) for 10 minutes before sparging with 20 L (5.3 gal) of water. Collect approximately 54 L (14.3 gal) of pre-boil wort.

4. Boil – 60 Minutes

• Add 19 g (0.67 oz) Pride of Ringwood at 60 minutes.
• Add Whirlfloc with 15 minutes remaining.
• Add the full 1 kg (2.2 lb) of dextrose during the final 10 minutes of the boil, stirring thoroughly until dissolved.

5. Flameout

At flameout, add 57.4 g (2 oz) Pride of Ringwood to provide a light floral aroma without excessive bitterness.

6. Chill & Transfer

Cool the wort to 20 °C (68 °F), transfer to a sanitised fermenter, and pitch SafLager S-189 yeast.

7. Fermentation

Ferment at 20 °C (68 °F) for approximately 14 days until gravity reaches around 1.000–1.001.

8. Package & Lager

Bottle or keg and carbonate to 2.4 volumes CO₂. For the cleanest flavour, lager the beer cold for several weeks before serving.

Brew Notes

• Brewed: 11 February 2026
• Bottled: 25 February 2026
• Pre-Boil Gravity: 1.029
• OG: 1.033
• FG: 1.000

This batch initially showed noticeable Sulphur while fresh on tap, most likely due to fermenting the lager yeast warmer than ideal. Extended cold lagering should significantly reduce these sulphur notes and improve the overall finish.

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