Boil 2,5 gallons water to remove the chlorine it contains, let cool and pour in the 5 gallon carboy (boil twice 1 ¼ gallon if this is more convenient). This can be done ahead of time -- the day before or while preparing the starter.
Boil 1 gallon water for 10-15 min to remove the chlorine. Reduce the heat to low and add 12 pounds of honey (around 1 lb of honey per gallon per 10 proof). Maintain at 150°F for 5 min [M1 p. 513] in order to « pasteurize » honey. Due to its pH, its hygroscopy and its hydrogen peroxide, honey is not a good candidate for a bacterial infection, the main hazard are wild yeasts [H4]; so it is not necessary to boil it, boiling would drive off some flavor. (See also sanitation in Syntheses). Remove the foam (it is made of protein which would make a haze in the mead). Cool down in the sink filled with ice. In the mean time, boil 1 gal water to remove chlorine and let it cool down. When the must is below 100°F, pour it into the carboy and add the starter. Then add water to make 5 gallons (or less if you plan to add honey later).
Homogenize the must and take a specific gravity (S. G.) measurement (figure on the right), it should be around 1,09-1,10 (it should lead to 25 proof). Take a sample and measure its pH.
Add the stopper and the air-lock (add some sulfite in the water to repel bacteria).
This step takes several weeks at 70°F (ideal temperature depends on the kind of yeast but in general high temperature are to be avoided, fermentation would be faster but the quality would be lower). (See also temperature in Synthesis). Do not shake the carboy as this could drive off volatile organoleptic compounds and modify the taste [V2] (this increases the speed of fermentation though, because yeasts at the bottom of the vessel are less efficient).
If a dessert mead (sweet and with a high alcohol content) is what you want, it is necessary that the initial S. G. be high (1.12 or 1.15). This may inhibit the fermentation, as yeasts do not like to have too much sugar at once. It may be a better idea to have an initial gravity (I. G.) of 1.08 or 1.10 and then add more honey after a week or so. When honey is added, it is safer to weigh it and extrapolate the change in density rather than use the hydrometer. Honey will not be well mixed immediately and the gravity will be under-estimated (even if the carboy is shaken and the must looks homogeneous).
The fermentation is done when the number of bubbles becomes very low. That is, when there is no more sugar or the alcohol content is no longer withstood by the yeast. It is also possible to choose to stop the fermentation before it is over, generally if a rather sweet mead is seeked. In this case extra care is necessary to prevent the fermentation from restarting (see sorbic acid in Chemicals).
The mead must not be left on the lees (especially when the weather is hot) lest the yeast will feed itself of them (autolysis) giving a bad taste [H2, h2].
Sanitize a new carboy, a rubber stopper, the hose, the funnel and the hydrometer. Boil ½ qt water to remove chlorine and let it cool down.
Place the new carboy lower than the first one. Hold the hose with one hand, both ends up and at the same height. Fill it entirely with water and stop one end (use the hand holding the hose). Remove the stopper and the air-lock. Place the free end of the hose in the carboy that contains the mead (be careful if the carboy is full) and then the other end in the new carboy. Siphon mead to the second carboy leaving lees in the first one (see figure). The hose must be at the bottom of the second carboy to avoid splashing, and therefore aerating, the mead (avoid oxidation).
If some air gets into the hose and the process stops, start over.
Take a S. G. measurement. Take a sample, taste it then measure its pH. If necessary, add some water so that the liquid in the carboy is close to the stopper (5 mm) as the less air the less oxidation. Put the air-lock back on.
Air brings in essentially two things: oxygen and bacteria. Bacteria are not something we are looking for (apart for the malo-lactic fermentation of wine). Oxygen, on the other hand, can be welcome or not, it depends. To start fermenting yeasts need energy, they get this energy from respiration, which requires oxygen. But then oxygen must be banished from the must, because mead -- if it behaves the same way white wine does -- is very sensitive to oxygen and will oxidize easily (browning, bitterness): see oxidation in A problem?
Maintain around 60 °F and rack as many times as required (in general the second racking takes place two weeks to one month after the first one, then rack every two months or so; it is pointless to rack if there are no new lees). Taste the mead each time you rack. If the taste is too flat, add some acid in a small sample (not in the whole batch). If the taste is improved, add acid to the whole batch. This can be done in several steps, adding little acid at a time to avoid adding too much.
If the temperature is lower than the fermentation temperature, check the airlock because the contraction of mead and air due to the drop of temperature can drive some of the water of the airlock into the mead. If rackings take place at room temperature and the mead is then stored at a lower temperature, the level of the liquid must be close to the stopper within a few millimeters because the contraction due to the decrease of temperature will increase the air space. So if there is 5 mm at the beginning, there could be almost 1 cm at lower temperature. Also check that enough water remains in the airlock. Add some if necessary, for an empty airlock is absolutely useless and the mead can be lost quite fast.
Bulk ageing lasts 3 to 6 months for light white wines and fruit wines, 6 months to a year for other white wines and light reds [V5]. Mead should be somewhere between 3 months and one year. In any case the mead should not be bottled before it clarifies and above all before the fermentation is over (if the mead is bottled too early, the fermentation could restart and bottles explode.)
What if the mead is not good? Either it is too young (can improve) or it is just bad [H13]. A batch which is not satisfactorily and may never be so should not be bottled. If some ageing seems necessary, let the mead bulk age until it prove good before bottling.
If the mead does not spontaneously clarify in a few months, fining agents can be added to speed up the process and rack until the mead can be bottled. Given the ageing needed for mead, it is pointless to hurry up and to want to bottle right after the fermentation stops. On the other hand, if mead really does not clarify, fining is an option which should not be refused a priori.
Before bottling, add sulfite to ensure the stability of mead during ageing.
Reference: chapters 14 to 16 in V2.