Frequently asked questions about homebrewing
Answers to common homebrewing questions: brewing water, fermentation, hops, bottling, carbonation and the Brauwerkstatt calculators.
Do gypsum and calcium chloride raise alkalinity?
No. The salts add calcium, sulphate and chloride, but no bicarbonate. Alkalinity stays the same; general hardness rises. In the mash, the calcium does lower residual alkalinity.
Why does nothing change when I change the calcium target?
With two salts you can only set two values. The amounts follow your chloride and sulphate targets; calcium follows from them. The calcium target is just a check value.
Alkalinity target or beer colour, which should I use?
Both aim for the same result, a mash pH of about 5.4–5.5. The fixed alkalinity target is simple; beer colour takes calcium into account and often saves a little lactic acid. The measured mash pH is what counts.
Can you taste a few mg/l of residual alkalinity?
No. About 18 mg/l of residual alkalinity shifts mash pH by only about 0.03, which is below the accuracy of typical pH meters.
Why does the pH of cold water drop so much after adding lactic acid?
Water has little buffer, and the CO₂ formed stays dissolved in cold water. It escapes when heated. In the mash the malt buffers strongly; only the lower KH matters there.
I added too much lactic acid. What now?
If alkalinity is too low, add untreated tap water. Under “If overdosed” the calculator shows how much to add and whether you need to top up the salts.
My mash pH is too low. What should I do?
Between 5.2 and 5.4, do nothing. Below 5.2, dissolve a little plain baking soda in water, stir it in, wait 5 minutes and measure again. The calculator gives the amount.
How do I measure pH correctly?
Take a small sample from the mash and cool it to about 20 °C (68 °F). Measured hot, the meter reads too low and the electrode ages faster. Calibrate the meter with pH 4.0 and 7.0 buffer solutions before brew day, and always store the electrode moist in storage solution, never in distilled water.
Why does my IBU differ from other software?
Each program uses slightly different assumptions, especially for the whirlpool and pellets. Differences of 2–3 IBU are normal and not noticeable.
My hops have a different alpha acid than the recipe. What now?
Bitterness rises directly with alpha acid. Enter your value in the final-beer calculator and adjust the amount until the target IBU matches again.
How much sugar goes into a bottle?
It depends on the target CO₂ and the beer temperature after fermentation. For example, a Kölsch at 5.5 g/l and 18 °C (64 °F) needs about 3.6 g (0.13 oz) of table sugar per 0.5 L (about 16.9 fl oz) bottle. The carbonation calculator works it out exactly.
Acid sanitiser (e.g. Star San) or a quaternary ammonium product?
For everything after the boil an acid sanitiser is more practical because no rinsing is needed. Quaternary ammonium products work more broadly but must be rinsed thoroughly with drinking water, as residues harm yeast and foam.
How do I scale a recipe to my batch size?
Open the recipe and enter your amount under “Batch size calculator” at the top. Mash water, sparge water and total water update right below as you type. With “Convert”, malt, hops, water, yeast and the amounts in the steps are adjusted, also in the PDF. Gravity, IBU and colour stay the same.
How much water do I need?
It depends on batch size, amount of malt, boil time and your system. The water volume calculator under “Calculators” works out mash and sparge water and tells you how hot the water has to be. After your first brew, enter the evaporation and losses of your own system under the fine settings.
Do I have to treat my water?
Not necessarily. Many beers work well with soft to medium tap water. With hard water and pale beers treatment pays off, because otherwise the mash pH is too high. The brewing-water calculator shows you what is needed.
My tap water smells of chlorine. What should I do?
Chlorine and chloramine give beer a medicinal taste. A Campden tablet neutralises both within minutes; the dose is on the pack. Free chlorine also escapes if the water stands open overnight, but chloramine does not.
My fermentation won’t start. What should I do?
Stay calm: it often takes 12–48 hours before you see anything. An airlock that doesn’t bubble means little if the lid isn’t fully airtight. Better check with the hydrometer: if the reading drops, the beer is fermenting. If nothing has happened after 2 days, check the temperature and pitch fresh yeast if needed.
My beer is still flat after 2 weeks in the bottle. What now?
Leave the bottles at room temperature (18–22 °C) for another 1–2 weeks, as yeast hardly works in the cold. Gently turn each bottle upside down once so the yeast mixes in again. If the beer stays flat, usually a cap was leaking or there was too little sugar in the bottle.
My beer is hazy. Is that a problem?
Usually not, and a wheat beer is even meant to be hazy. Irish moss in the boil, fast chilling of the wort and a few weeks of cold conditioning make beer clearer. Haze that only appears when the beer is cold is chill haze. It is harmless.
How long until the beer is ready?
Brew day about 5–7 hours, fermentation 1–2 weeks, bottle conditioning 2 weeks. Ales are ready after about 4 weeks, lagers like the Helles need 6–8 weeks including cold lagering.