Free tool
Honey is short on the nitrogen yeast needs, so a mead ferments far more happily if you feed it in stages. Put in your batch size and target strength, and it gives you a Fermaid O dose and a simple staggered schedule.
Add 1.13 g four times: at pitch, then at 24, 48 and 72 hours (or by gravity, at pitch and then around a third and two thirds of the way down). This follows the TOSNA approach, about 1 g of Fermaid O per litre for a 14% mead scaled to your target. Use organic Fermaid O, rehydrate your yeast with GoFerm separately, and stir gently to release the CO2 with each dose.
Dumping all the nutrient in at the start can stress the yeast and leave harsh nitrogen behind. Feeding it in four small doses over the first three days keeps the yeast healthy through the busiest part of the ferment, which is the whole idea behind TOSNA. This tool gives a sensible estimate, about a gram of Fermaid O per litre for a 14% mead scaled to your target. It is a starting point, not gospel, so lean on your yeast maker's notes for anything unusual.
New to mead? Our mead recipes and yeast guide are a good place to start.
TOSNA stands for tailored organic staggered nutrient addition. Honey has very little of the nitrogen yeast needs, so mead ferments do better when you feed them organic nutrient (Fermaid O) in several small doses over the first few days rather than all at once.
As a rough guide it is about 1 gram of Fermaid O per litre for a standard 14% mead, scaled up or down with your target strength. For a 4.5 litre batch at 14% that is around 4.5 g in total, split into four.
Split the total into four equal doses: at pitch, then at 24, 48 and 72 hours. If you prefer to go by gravity, add at pitch and then at roughly a third and two thirds of the way down. Stir gently each time to release the trapped CO2.
GoFerm is a rehydration nutrient you mix with warm water to wake the yeast up before pitching, separate from the staggered feeds. TOSNA deliberately uses organic Fermaid O rather than DAP, which is a harsher inorganic nitrogen that can be rough on yeast at higher strengths.
Demijohn Journal keeps your recipe, nutrient additions and gravity readings together, so you can repeat what worked. Free.
Get Started Free