Question 1

How much water do I add to cut 2 L of 63% spirit down to 40%?

Accepted Answer

The quick estimate uses conservation of alcohol: the ethanol volume before and after dilution is the same, only the water changes. Alcohol present: 2.00 L x 0.63 = 1.26 L of pure ethanol. Final volume needed: 1.26 / 0.40 = 3.15 L. Water to add: 3.15 - 2.00 = 1.15 L. Two refinements matter in practice. First, ethanol and water contract on mixing, typically 1 to 3%, so the true water requirement is slightly more than the simple arithmetic suggests; the calculator's OIML Precise mode handles this. Second, add the water in stages and re-measure with an alcoholmeter at 20 degrees C between additio

Question 2

My sugar wash started at 1.090 and stopped at 1.020 after a week. Stuck or finished?

Accepted Answer

Stuck. A healthy sugar wash ferments essentially dry, to 1.000 or below, because there are no unfermentable dextrins in plain sucrose. Stopping at 1.020 means roughly a quarter of the sugar is still sitting there unfermented. The likely cause at 1.090: combined osmotic and alcohol stress on underfed yeast. At 1.020 the wash is already near 9% ABV, and if the nutrients went in as a single dose at pitch, the nitrogen ran out just as the alcohol stress peaked. The restart sequence that usually works: confirm temperature is in the yeast's range, add a small nutrient dose, rouse gently to resuspen

Question 3

How much do I throw away as foreshots on a 25 L wash run?

Accepted Answer

Work from charge alcohol, not from a flat percentage of the collection. The rule is 2.5 mL of foreshots per litre of wash charge, with a minimum of 25 mL. For 25 L of an 8% wash: 25 x 2.5 = about 63 mL discarded, and rounding up costs almost nothing. Two notes on the reasoning. The foreshots discard exists because acetaldehyde and ethyl acetate concentrate at the very front of the run, and those compounds have well-documented unpleasant acute effects. It is not about methanol, which a clean sugar wash barely contains. And the discard is a safety margi

Question 4

My alcoholmeter reads 84% but the spirit is at 30 degrees C. What is the real strength?

Accepted Answer

Lower than the display shows. Warm spirit is expanded and less dense, the alcoholmeter sinks deeper, and the scale reads a few points high. The correction therefore goes downward, and the direction trips people up constantly, so here it is done properly. Alcoholmeters are calibrated at 20 degrees C. At 30 degrees C the reading of 84% corresponds, via the OIML alcoholometric tables, to a true strength of roughly 80.5 to 81% ABV at 20 degrees C: the warm reading overstates the alcohol because the whole liquid expanded, not just the water. The practical rule: near spirit strength, each degree ab

Question 5

I have 5 L at 60%. How many 700 mL bottles at 42% will that make?

Accepted Answer

Alcohol conservation again, in two steps. Total ethanol: 5.0 x 0.60 = 3.0 L. Final volume at 42%: 3.0 / 0.42 = 7.14 L. Bottles: 7.14 / 0.70 = 10 bottles, with about 140 mL left over for the tasting glass. Contraction shaves the real final volume slightly below 7.14 L, so plan for 10 bottles rather than hoping for 11, and remember the practical losses: racking, filtering and the wet film every vessel keeps all come out of the same budget.

Question 6

Added water to my gin and it instantly went cloudy. Did I ruin it?

Accepted Answer

No. That is louching: botanical oils dropping out of solution as the alcohol strength falls. Ethanol was holding those oils dissolved; below roughly 46% ABV, and higher still for oil-rich recipes, it no longer can, and the emerging micro-droplets scatter light. Your options, none of which involve pouring it out: keep the bottling strength a little higher, at or above the point where your recipe stays bright; dilute more slowly next time, resting between additions, which often keeps the same final strength clearer; or chill the diluted gin near 0 degrees C for a day and filter it cold, removing the

Question 7

Is one 5 g packet of EC-1118 enough for 19 L of mead at 1.100?

Accepted Answer

Lalvin doses EC-1118 at about 25 g/hL, scaled up for high gravity. 19 L at 1.100 works out to about 6.3 g, so one 5 g packet is slightly light; a packet and a half removes the doubt. Rehydrate in about 63 mL of water at 30 to 35 C before pitching.

Question 8

One calculator says 4 g of Fermaid-O per addition, another says 20 g. Which is right?

Accepted Answer

The difference is the organic nitrogen efficiency factor. Fermaid-O provides about 40 ppm YAN per gram per litre as a raw mass balance, but organic nitrogen is used roughly four times more efficiently, the basis of the TOSNA protocol. For 19 L at 13 percent that means about 28 g total, roughly 7 g per addition at 0, 24, 48 and 72 hours, not 111 g.

Question 9

How much sorbate and Campden to stabilize 23 L of cider before back-sweetening?

Accepted Answer

At pH 3.3: 6.2 g of potassium sorbate (200 mg/L sorbic acid at 74 percent) and about 1.0 g of potassium metabisulfite, roughly two Campden tablets, for a free SO2 of about 25 mg/L. Confirm fermentation is finished, rack, dose both, then wait a day before sweetening.

Question 10

My mead finished at 0.996. How much honey to sweeten 19 L up to 1.010?

Accepted Answer

14 gravity points at roughly 3.7 g of honey per litre per point comes to about 52 g/L, or just under 1 kg for 19 L. Stabilize first and add in stages to taste.

Question 11

How much boiling water raises a 6 kg mash in 16 L from 62 to 68 C?

Accepted Answer

The mash thermal mass is 0.41 x 6 + 16 = 18.5 L equivalent. With 98 C water: (68 - 62) x 18.5 / (98 - 68) = about 3.7 L. Stir while adding and confirm with a probe.

Worked Answers