First brew: dry hopped mead, probably stuck. How to best proceed?

Grats on your first brew!

This has been well answered on process corrections.

The harsh bitter is from the hop tea, if the cascade was 6.6%AA 60min boil you have about 45 IBUs there which is the top end of pale ales and the start to some IPAs. With no malt to balance, it can taste much more bitter.

At your fermentation temp you can expect some fusel alcohols adding to a harsh taste. I would keep 68°-72°F as your top end during the vigorous fermentation.

The cooler temp will force the yeast to work slower and gives them time to build up their cell walls to tollerate the increasing ABV and be able to hang on longer for the whole job. I suspect this was the cause of the stall.

I am going to repeat a lot of what Molot has already said but will add a few extra points:

1. start with healthy yeast, if possible make a starter at least 24 hours in advance. Use a whole packet at once, maybe use 2 packs.
2. make sure you have cleaned off all bleach, any left will ruin your brew
3. add all your nutrients at the start when the yeast need them most Stick with your staggered yeast nutrient additions.
4. leave it to sit on the yeast cake for at least a couple of weeks to get those last few points of attenuation.
5. Make sure you only use single variety honey, never use blended honey as you will get medicinal off flavour if there is any eucalyptus honey blended.
6. Hop very very lightly, as mead usually has little residual sweetness unless you use a low attenuating ale yeast such as S04; and as such can end up horribly unbalanced.
7. I usually add juice of a lemon or orange to my meads to ensure the yeast has some fresh vitamins. Along with the recommended amount of yeast nutrients.

My process at this point would be to ignore fixing it now, but to bottle it up in plastic soda bottle and store it for 1-2 months then re-taste it.

And, secondly start again, with a new batch, thinking on the points above.

Finally have you used brewtoad or brewersfriend or similar brew planing tool to draw up your recipe and pitch rates, also helps you check the sweetness bitterness balance, if not I heartily recommend you do.

We make a lot of meads and I think the majority of your process looks pretty good. (Including the staggered nutrient additions). You might want to consider using a blend of nutrients like DAP and Fermaid K. They both contribute different vital compounds.

I suspect that the hop additions pre ferment didn't help you much. That yeast is not very hop tolerant as it is a wine yeast. Your title indicates a dry hopped mead. I'd recommend not boiling any hops to create iso-alphas. Just ferment out a great mead and then dry hop for hop aromatics. I haven't found too many meads that benefitted from a hop bittering charge of any sort.

Lastly, at day 9 you should have checked the SG first, then decided to leave it be on the yeast. Now that you've removed the yeast cake its going to be tough to get it going again. 1.010 isn't all that bad. Its probably still going to be drinkable.

If you want to get it going again, you could pitch an active but of yeast. Get get another packet rehydrated (a full packet) pitch it into some honey based starter solution (~1.030SG) and wait for it to truly start bubbling. Then pitch the whole active lot. You need awake and active yeast to move the gravity of something that is already pretty alcoholic.

IMO, chasing mistakes and trying to correct them often doesn't make for great end results. At least I haven't had a lot of luck trying it. Sure the gravity may move but you've had a stressed ferment already and its not likely that just moving the gravity more will change that aspect of it. I'd say drink this one or let it age for blending later. Start again with the same idea making the critical changes and you'll get 1. a better result and 2. you'll be more the wiser for it.

Good luck.

My answer will not be full, but there are some things I can tell:

1. Splitting half a dollar worth yeast packet in five? Why?! Especially in double-difficult brew, as it is both pretty high gravity (has to be for 10% ABV), and it is mead (no nutrient found in wort)

2. Nutrient. Why add it in parts? I always understood we want yeast to multiply over as short period as possible. Slowing down nutrient addition is not a way to do it, it only starves your yeast more than usually needed.

3. Can't really see a point in degassing so soon.

4. Racking off? When your yeast is on the bottom? This can't help.

Now, as for fixing it. Does it taste like it has unprocessed nutrient? If so, then do not add more nutrient!

Go-ferm might be a way to go. Also, I'd advise you to overpitch this time. It will both increase chance that yeast will metabolize remaining nutrient, and that they will be able to process sugars you have remaining.

You can also consider making a MDE starter. Aerate it well. When it's ready, let yeast settle, get rid of liquid, and add yeast slurry to your mead. Stir well, without aerating.