Brewing a gose at home with salt and coriander
Gose is a German wheat beer soured with lactic acid and seasoned with salt and coriander. Kettle souring makes it manageable at home. Getting the salt right is the difference between refreshing and brackish.
Gose is a wheat beer with a seasoning problem to solve
Gose comes from Goslar and was later brewed mainly in Leipzig. It is pale, cloudy and low in alcohol, usually 4.2 to 4.8% ABV from an original gravity around 1.036 to 1.056. About half the grist is wheat malt. Bitterness stays very low, around 5 to 12 IBU, because hops clash with the sourness.
What makes it a gose rather than a Berliner weisse is the seasoning. Salt should be noticeable on the lips but never the main flavour. Coriander should smell fresh and citrusy, not soapy.
Kettle souring gives you control
Kettle souring means letting Lactobacillus acidify the wort before the boil, then boiling to kill it. Your fermenter and kit stay free of souring bacteria. The steps:
- Mash and collect the wort as normal, then boil it for 10 minutes to sanitise it.
- Cool to the temperature your Lactobacillus culture prefers, often 35 to 43 °C.
- Pre-acidify with food grade lactic acid to about pH 4.5. This stops other bacteria getting a foothold before the culture takes over.
- Pitch the culture, purge the headspace with CO2 if you can and cover with cling film on the wort surface.
- Hold the temperature and check pH every 12 hours until it reaches 3.3 to 3.5.
- Boil for 15 minutes, add the hops, salt and coriander, chill and pitch a clean ale yeast.
Keep hops out until the souring is done. Most Lactobacillus strains stop working with even a few IBU present.
A grist and schedule for 20 litres
For 20 litres at an original gravity near 1.040:
- 1.8 kg pilsner malt (50%)
- 1.8 kg wheat malt (50%)
- A handful of rice hulls to help the run-off
- Mash at 65 °C for 60 minutes
- 15 g of a 4% alpha hop for the last 15 minutes of the final boil, about 4 IBU
Ferment with a neutral ale yeast at 18 to 19 °C. The low pH slows yeast, so pitch a full sachet even for this light beer and expect it to take a few extra days to finish.
Salt is measured in grams per litre
A sensible starting dose is about 0.5 g of salt per litre, so 10 g for 20 litres. Some brewers go to 0.75 g per litre. Past 1 g per litre the beer tips into briny for most people. Add it in the last five minutes of the boil.
Use plain non-iodised salt or sea salt with no anti-caking agents. One Indian swap we would avoid: kala namak (black salt). It carries sulphur compounds that smell of boiled egg, which a pale sour beer amplifies. If you want to try it, dose a 500 mL sample first.
Coriander has to be fresh and crushed
Use 10 to 15 g of whole coriander seed for 20 litres, crushed just before it goes in at flameout. Indian kitchens are full of good coriander, which helps, but jars that have sat open for months taste dusty. Smell it: it should be bright and citrusy. Our witbier guide covers the same spice in a softer beer.
Fermenting a sour wort in Indian heat
Once the wort is soured and boiled, it is an ordinary ale fermentation. Hold 18 to 19 °C with a water bath or a fridge and controller, as in our guide to fermentation temperature control at home. Warmer than 22 °C and the yeast adds fruity esters that blur the clean tartness.
Carbonate to about 2.7 volumes. High carbonation lifts both acidity and salt. Sour beers also attack bare metal, so check that your keg fittings and taps are stainless.
Tasting the balance before you package
Gose rewards a bench check. Before you bottle or keg, pour three small samples. Leave one as it is, add a pinch of salt to the second and a squeeze of lime to the third. If the salted sample tastes better, your dose was cautious and you can add a little dissolved salt to the bottling bucket. If the plain one tastes cleanest, leave it alone.
The acid level should land around pH 3.3 to 3.5 in the finished beer, which reads as bright and lemony. Below about 3.2 it starts to bite at the back of the throat. Fruit versions are popular: mango, guava and kokum all suit the style. Add fruit after primary fermentation and expect a second burst of activity as the yeast works through the extra sugar. Wait until gravity is stable for three days before packaging, or the bottles will over-carbonate.
A pH meter comes before the culture
Order a calibrated pH meter and two buffer solutions before you buy the Lactobacillus. Kettle souring without a meter is guessing. pH strips are hard to read in cloudy wort. Calibrate the meter at pH 4.0 and 7.0 the day before you brew.
Common questions
How much salt goes into a gose?
Start with about 0.5 g per litre, so 10 g in 20 litres, added in the last five minutes of the boil. Above 1 g per litre usually tastes briny.
Why do I need to pre-acidify before souring?
Dropping the wort to about pH 4.5 with lactic acid discourages other bacteria while the Lactobacillus gets going.
Can I add hops before kettle souring?
Keep them out. Most Lactobacillus strains are inhibited by even small amounts of hop bitterness.
