Calculating Mead Gravity and Nutrient Additions

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10centBros

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Gravity questions. First off, how does one calculate ending gravity for mead? I read somewhere that you just plan for a 1.000 end gravity, but there's go to be something more accurate than that.

Also, it's gotten pretty warm in CA the past few weeks and I hadent checked my gravity during this period. I try to add nutrient at the 1st and 2nd sugar break, but I think I missed those on 2 of my meads.

Brewed 3/19/14
OG - 1.095
Now it's down to 1.046
Wyeast: 4632 Dry Mead

If I was aiming for a FG of 1.000, the first sugar break should of been at 1.064, which I've obviously missed. Should I still add nutrient?

Another batch:

Brewed 4/24/14
OG - 1.103
Now it's down to 1.038
Yeast: EC-1118

Again, if I'm aiming for a FG of 1.000, the first sugar break should of been at 1.069, which I've also obviously missed. Again, should I still add nutrient? Also, with this batch, is that unreasonably fast for fermentation, dropping that much in 3 weeks?

Any help would be greatly appreciated
 

MarshmallowBlue

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So, calculating the FG of a mead actually is very hard. There's a lot that goes into it. Many things will factor in as to where your mead will stop fermenting;
1: Yeast selection- Certain yeasts will ferment to their tolerance, so if you put some yeast X with a tolerance of 12% in a must of 1.130, it won't ferment to 1.000. BUT, That listed tolerance is also an average and the yeast can ferment higher or lower based on cell count/ colony health etc.
2: how well you treat your must; Proper nutrients and aeration mean healthier ferments which mean you should be able to reach or go a bit beyond those tolerances.

Yeast selection should involve 3 things (at least for myself).
• Flavor characteristics the yeast will produce
• Temperature Range
• ABV tolerance (usually not a concern for me because I aim for around 12 to 12.5% with typical batches).

As far as adding nutrients late: You can, however it may not do anything for you. Some say that adding late will just feed things other than the yeast (any bacteria or what have you) and possibly contaminate your batch. I haven't heard about this and it doesn't make too much sense either if your sanitation was good when the batch was started. You can add it if you feel like it (I wouldn't aerate it though), But it may finish just fine without it.

When you treat a mead well, with nutrients, aeration, PH, temperature etc. You can ferment a mead fully in 2 weeks, so it's not uncommon in my experience for a mead to finish fermentation in that time. However, a finished ferment and a finished mead are different, you still need to bulk age (for more even flavors throughout the batch), and clear your mead before packaging.
 
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10centBros

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Thanks so much for clarifying some of by hose concerns for me. To follow up: With aeration and pH, can you go into a little detail on proper aeration techniques and frequency for a mead? Would it be different for a melomel? And for pH, is that just a matter of adding acid if need be?

I think I'll hold off of adding nutrients and just give it some time. And as for calculating the gravity, is there a big scientific equation where you plug in all the factors to which you might get an approx gravity? I only ask because my nutrient additions have been based off the mead finishing at a 1.000 gravity, and if that's not the case, how would a somewhat amateur mead-maker like myself know when to add nutrient/energizer? Thanks again!
 

fatbloke

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Thanks so much for clarifying some of by hose concerns for me. To follow up: With aeration and pH, can you go into a little detail on proper aeration techniques and frequency for a mead? Would it be different for a melomel? And for pH, is that just a matter of adding acid if need be?
There's no "proper" or "best" really. Aeration i.e. the agitation with a view to getting some oxygen into the mix to assist with yeast health/development, can be done with whatever kit you have available - as long as you use a sensible hygiene technique (no-rinse, maybe just crushed campden tablets/acid mix etc - anything will do to sanitise the kit as long as it's not gonna leave any residual taste - like bleach! that's a no-no), so that all the kit has been sanitised before use. A lees stirrer maybe if you're using a carboy type fermenter, or an "air stone" either with pumped air or even pure O2.

Buckets are a bit easier, as you can get away with balloon whisks, electric or manual, stick blenders, or the airstones above etc.

There's no strict regime either. Most will try and aerate at least once a day until the batch hits the 1/3 sugar break (where the yeast has consumed 1/3rd of avaialb sugars).

pH ? not a case of adding acid. Ferments are usually acidic enough (don't believe me ? just mix some honey and water to a normal ferment sort of level, say to 1.100 or thereabouts and bung a pH meter in - you'll likely get between the mid 3.X and mid 4.X). It's usually a case of having the correct carbonate available so if it drops below 3.0 pH during the ferment, you can bring the level back up a bit (potassium carbonate is considered the best to have available).
I think I'll hold off of adding nutrients and just give it some time. And as for calculating the gravity, is there a big scientific equation where you plug in all the factors to which you might get an approx gravity? I only ask because my nutrient additions have been based off the mead finishing at a 1.000 gravity, and if that's not the case, how would a somewhat amateur mead-maker like myself know when to add nutrient/energizer? Thanks again!
Calculating gravity is just a case of hydrometer readings. Most easily (obviously) is to measure the honey and water mix. The gravity would need to be considered higher if you used a fruit ingredient i.e. the honey/water gives 1.XXX, then you add fruit and that can become 1.YYY

Generally speaking, you would get a more accurate reading if you pulped/puree'd/juiced the fruit, but it's much easier to use fruit that hasn't been processed, or processing is to a minimum (removal of stone/pip/pit where possible etc) as whole or larger pieces of fruit are easier to handle/manage, and that out weighs the hassle of pulping/puree/juice in most cases - given how much of a nuisance it can be to rack off of pulp etc....

As for nutrient addition being based from gravity ? Yes, that's fine. You should be OK just using the gravity of honey/water element to work that out. Just measure it with your hydrometer. Adding fruit will increase gravity but generally fruit will provide some nutrient value as well as sugars etc.

For actually adding the nutrients, if you know what the tolerance of the yeast is, how much sugar is in the must (at least from the honey/water as a guide), then you'd say use something like as much honey as is needed to produce a dry mead, ferment to that, then stabilise and back sweeten. YOu know the starting gravity, so it's normal/routine to add up to 85% of the total amount needed for the batch once fermentation has started, the rest being added by the 1/3rd sugar break, but its up to you if you wanted to add say half, then maybe 1/4 in 2 additions or 1/8 in 4, just that yeast don't metabolise non-organic nitrogen after about the 1/3 break. If you think you might need something to push it along later on, then organic nitrogen is the thing. Either FermaidO (as different from the K stuff), or yeast hulls or even just boiled bread yeast.
 
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10centBros

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Wow, very informative! Thank you so much, I'll certainly be applying some/most of that information on the next batch! Very much appreciated!
 
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