Stabilize & Sweeten
Sorbate, sulfite and sweetener for a finished ferment
Digital pH Meter: The sulfite dose depends directly on pH, and test strips are not precise enough in the wine range. A calibrated meter is the difference between guessing and dosing.As an Amazon Associate we earn from qualifying purchases.
View on AmazonHow This Is Calculated
Three additions come out of this calculator, and the order matters: sulfite and sorbate first, sweetener a day later once the stabilizers are mixed through.
Potassium sorbate. The standard stabilizing dose is 200 mg/L of sorbic acid. Potassium sorbate is 74 percent sorbic acid by weight, so that means about 268 mg/L of the powder. Following Peynaud, the calculator raises the dose to 250 mg/L sorbic above pH 3.5, where sorbate is less effective, and it never exceeds the 300 mg/L sorbic acid maximum permitted in finished wine under US regulations.
Potassium metabisulfite. Only molecular SO2 protects the ferment, and its share of free SO2 falls steeply as pH rises. The calculator targets 0.8 mg/L molecular SO2 using the standard relationship from wine chemistry:
Potassium metabisulfite yields 57.6 percent of its weight as SO2, which converts the free SO2 target into grams of powder. At pH 3.4 the target lands near 32 mg/L free SO2; by pH 3.7 it is roughly double.
Sweetener. Each gravity point (0.001 SG) requires about 2.6 g of sucrose per litre, the same density relationship used across this site. Honey is treated as 80 percent fermentable sugars, so it needs about 3.7 g per litre per point, shown as an approximation because honeys vary.
The Order of Operations
Stabilization only works on a ferment that is genuinely finished and clear. Take two hydrometer readings three days apart; if they match, fermentation is done. Rack off the lees, because sorbate stops yeast reproducing but does nothing about the millions of viable cells sitting in the sediment.
Dissolve the metabisulfite and the sorbate in a little water and stir both into the racked batch. Wait at least 12 to 24 hours before sweetening, so the stabilizers are fully distributed before any sugar arrives. Then sweeten in steps toward the target gravity, tasting as you go: sweetness perception varies with acidity, and a high-acid mead carries 1.015 the way a soft one carries 1.008.
Never rely on sorbate without sulfite. Lactic acid bacteria metabolise sorbic acid into a compound with a pronounced geranium smell, and the fault is permanent. The sulfite dose exists to keep those bacteria out of the picture. Check your finished strength with the Mead ABV Calculator or Wine ABV Calculator, and if you are still planning the ferment, dose nutrients with the Mead Nutrient Calculator first.