MX1 said:
You Too Brew uses Fermaid-K and Fermaid-O depending on dry or liquid yeast, can is there a reason? Can just one be used across both yeast?
bernardsmith has provided some good info there. The yeast need nutrients and that main nutrient is Nitrogen. If you've seen references to YAN, it is talking about Yeast Assimilable Nitrogen. So while they need Nitrogen it has to be the right type that they can use.
Fermaid-O and Fermaid-K will both provide that Nitrogen. Fermaid-K used DAP to help provide this while the O version does not. An analogy that I find useful when it comes to DAP is that it is akin to giving the yeast steroids in place of a good nutritional diet. The yeast actually will take the DAP Nitrogen preferentially over other types. For myself I typically user Fermaid-O as I'll try and keep the mead as organic as possible but there are times I use DAP. If I am using any citrus in primary, say in a tea that has it, I'll use some DAP as it seems to help kick that fermentation off well when the yeast tend to not like the acidity of the citrus. After ~9% abv, the yeast will not take up and use DAP and you will potentially be left with it adding its flavors to the mead.
MX1 said:
Concentrates, Purees, and extracts; assuming they are from a good source, can they be used? If so what is the best way? Esp extracts, like maple or vanilla, orange etc.
Freeze-Dried items, are these good to go? I have access to a freeze drier, so apples, and other fruits would this be good to use?
I generally have to agree with what bernardsmith said regarding these items and use that as a guideline. Somethings like frozen fruits can be used in primary and/or secondary and each will give you a different result. In the case of something like strawberries I tend to use them only in secondary after stabilizing as the primary fermentation uses all the sugar without really leaving much in the way of flavor. A mixed berry mix can work well however you want to use them.
MX1 said:
As far as final sweetness, I know there is a difference between actual and perceived, but should I be fermenting to stop at my targeted gravity, or let it go dry and back sweeten? I also know that that may depend on if I want to add flavor with the back sweeting, like a flavorful honey, or a nice barrel aged maple syrup.
In general figure out where you want the ABV to be and then calculate the needed honey that is in addition to any fruit or juices you will be using in primary. At that point, let it go dry. You can then taste for perceived sweetness and decide how much you want to back sweeten. That is a personal preference and for my tastes a measured gravity of 1.015 is usually at about my typical maximum sweetness... but let your palette tell you where you want to be.
I have a Buckwheat & Orange Blossom traditional mead that I make that will finish between 1.00 and 1.004 and I do not back sweeten it as the floral aroma and perceived sweetness is perfect for me. Maybe some day I'll sweeten some and see if I like it any better.
Trying to stop a fermentation or hit a specific gravity is just very difficult and not always repeatable. My personal experience with certain Ale yeasts shows that I'll get 110 to 120 points of gravity drop and I can usually target a high enough gravity to finish with sugars left over. This assumes proper nutrients, using Go-Ferm while getting dry yeast going and a fairly steady temperature. Wyeast 1388 seems pretty good at going through 120 points while SafAle S-04 or US-05 will go through 110 points and sometimes get to 120 points eaten.
With the above said, it is much more reliable to go dry and then back sweeten if you need/want to. Adding fruit in secondary (after stabilizing) can add to your gravity as the sugar extracts. I have the best strawberry field near me that produces very sweet fruit and I will use about 1.25Lb of chopped-frozen strawberries per gallon in secondary and after about 7-10 days the fruit has gone white and added about .004 to the gravity. Fruits like strawberries are, IMO, best kept in a bag for easy extraction out of the mead and it doesn't muddy it up as bad.
MX1 said:
One other question, Cyser, melomel, are styles of Mead? what do we call the Dry, Off Dry, Sweet descriptor?
As far as I know they are just general descriptors for the sweetness of the mead.