LalBrew Voss is a warm-fermenting kveik ale yeast. Its useful trick is a manufacturer-supported high temperature range. To plan a batch, identify the exact product, choose a temperature you can maintain and measure fermentation progress. “Voss” on a recipe is not enough to specify a pitch or a packaging date.
LalBrew Voss: temperature, attenuation and character
This guide uses Lallemand's dry LalBrew Voss specifications. The manufacturer identifies the culture as coming from Sigmund Gjernes in Voss, Norway, and describes a relatively neutral profile with light orange and citrus character. Its published figures are reference ranges, not a prediction of your final beer. Lallemand Voss technical data sheet.
| Specification | Manufacturer reference |
|---|---|
| Fermentation temperature | 25–40°C / 77–104°F |
| Optimal range | 35–40°C / 95–104°F |
| Apparent attenuation | 76–82% |
| Flocculation | Very high |
These figures describe this commercial product. Check a different supplier's instructions if you have a liquid Voss culture or a mixed farmhouse culture.
How long does Voss take?
Lallemand reports about two days at 40°C, three to four at 30°C and five to seven at 25°C in its standard test wort. Pitch, handling and wort nutrition affect the result. These are fermentation observations, not a guarantee that a home batch is ready to package on that day. See the technical sheet above.
Build your schedule around checkpoints: record the starting gravity, record the actual fermentation temperature and compare later gravity readings. The American Homebrewers Association's hydrometer guide explains repeat readings for judging fermentation completion. A batch that has stopped changing at an unexpectedly high gravity needs investigation before bottling.
Calculate the pitch for a 20-litre batch
Lallemand's published pitch range is 50–100 g per hectolitre. One hectolitre is 100 litres, so a 20-litre batch is 0.20 hL: 50 × 0.20 = 10 g at the lower end and 100 × 0.20 = 20 g at the upper end. Manufacturer pitch-rate reference.
This arithmetic converts units; it does not select the right point in that range for every wort. Use the current package guidance for the exact product and batch. Do not copy a liquid-yeast cell count into a dry-yeast weight calculation.
Try it: what is the same range for 10 litres?
10 litres is 0.10 hL. The corresponding range is 5–10 g. The weight halves because the volume halves; the rate per hectolitre stays the same.
Choose a use or substitute deliberately
A warm-fermented ale is a clearer learning goal than promising a lager from an ale yeast. For a first comparison, keep the malt bill and hop schedule steady and ask one question: how does your chosen fermentation plan affect the result?
If Voss is unavailable, choose a replacement by the job it must do. Compare its supported temperature, pitch instructions, attenuation and supplier flavour description. A familiar kveik name is a candidate to investigate, not proof of an identical culture or interchangeable process. If your temperature plan falls outside the replacement's instructions, revise the plan before brewing.
Turn the guide into a learning experiment
Use the Beer Lab to practise recipe decisions, then write a short batch record: exact yeast product, amount, original gravity, temperature observations, later gravity and what you would change next time. Keep simulator predictions separate from measured results. A useful result is a decision you can explain, even when the batch does not match your first estimate.