Thanks for all the replies!
What temperature is the room where your mead is located?
What yeast nutrients are being used?
Its somewhat puzzling about why its not fermenting.
Some thoughts are:
Yeast energizer is best used when re-hydrating the yeast. Beyond that, yeast nutrients are used.
The recommended method is to add yeast nutrient 24 hrs after the yeast has been pitched.
I'd try to get the yeast going again by stirring it up and bringing the fermenter to a warmer location, if available.
Nutrient is from RJS Craft Winemaking. Contains DAP, Yeast Hulls, Vitamin B complex, and Magnesium Sulfate
Energizer is from Brewcraft. No ingredients but claims to be "high in nitrogen, potassium, and phosphorus"
I read so many different things about nutrient and energizer. Couldn't find a basic mead recipe on this site so i improvised.
I gave it a stir and turned up the thermostat a bit, I see some slow bubbles...
What's the temperature? What's the pH? what's the sell by date of the yeast? How well did you aerate the must? Those are my questions. My observation is that 5t of nutrient in about 6 gallons of must is an enormous amount. Who makes this nutrient? I use about 1/4 t to a gallon. I am not sure what "energizer" does. I never use it. But here's what I would do:
1. Get another pack of yeast and rehydrate this in say, 1 cup of water with either Goferm (it's nutrients designed for rehydrating - rehydrating with standard nutrients will damage or kill yeast cells) or with simply a low concentration of honey or sugar and water (to a gravity of about 1.040).
2. When you know that the yeast is actively fermenting add 1 cup from your stalled batch to the starter and watch.
3. When you know that the batch you added is being fermented (You know because you are measuring the change in gravity) then you add 2 cups from the stalled batch: the idea being that each time the starter ferments the added batch you add the same volume to the volume that is fermenting (doubling the volume each time). This process of transferring from the stalled batch to the starter batch can take a day or more to complete. What the process does is shifts the fermentation away from the batch that may have a systemic problem to a batch that you know does not and you use the volume and energy in the starter batch to swamp any problems in the stalled batch.Try it.
Temperature is roughly 15-19C where it's brewing, I read that's great for D47. When I went away the temp probably hovered around 14 or 15 for a few days. I'll keep it a little warmer now.
Yeast should have been good, came in a pack of 10, the best before date is May 2021. I keep all my yeast in the fridge until I'm going to use it then let it come up to room temp before use.
Thanks for the restarting suggestion. You recommended this last time I got stuck and it worked for a little while, then it got to a point where the must stalled out again (1.020) and I couldn't get it going. I managed to save 2 gallons of my 10 though...
I'll bring a sample in to work to figure out the pH. What do you guys use? Strips?
Reality check:
- Doing the math 6kg of honey (13.25 US Pounds) added to 5 gallons water = roughly 1.075 OG with a total volume of roughly 6 gallons. (Check)
- D47 yeast has an alcohol tolerance of ~14% (I have pushed it greater than 15%) and a temp range of 60 - 68 Deg F (15-20C) You are well within the alcohol tolerance of your yeast. (Check) Temp of your brew area?
- Agree with Bernard for a traditional mead with this yeast sounds like a lot of nutrients. But depends on the nutrient i guess. (I use 2.5tsp Fermaid-O spread out over 4 additions) I only use 1 tsp energizer Go-ferm in a starter if I use it at all.
- pH is important - At this stage should be between 3.6 and 4.6.
- What water did you use? - Anything from a municipality likely has water treatment chemicals in it that could hinder your yeast. Chlorine, fluoride etc.
In addition to what Bernard said...
- Kick your temp up to 66-68DegF
- Check and adjust pH accordingly 3.6-4.6
- Aerate the heck out of it by shaking it or use a lees stirrer and drill a couple times a day until SG of 1.045 or so. (START SLOWLY - Mead fountains are really messy - Think Diet coke and Mentos)
- Give it a couple days and let us know how it is going.
Good Luck
For my starter I used tap water cause I read an article saying that mineral free water is hard on the yeast (
https://morewinemaking.com/web_files/intranet.morebeer.com/files/wineyeastrehydration09.pdf)
For the rest of the 5 gallons I use demineralized water.
I'll keep stirring a few times a day and keep the temp up a little.