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View Full Version : SNA - does anyone actually know what's best?



Jim H
07-02-2013, 06:35 PM
Some of the resident experts here are doing nifty experiments with yeast varieties and figuring out the ABV calculations, so maybe someone here knows the answer to this.

There are several variations to adding nutrients. Not only are there different nutrients and combinations, but there are also different additions schedules.

Has anyone here done an experiment at home with stepwise additions versus feeding all at once? Was there an actual difference to the final product?

Jim H
07-07-2013, 08:14 PM
Bumping the thread... still curious if anyone can shed light on this.

Bob1016
07-08-2013, 11:44 AM
I know that two steps (begining and 1/3 sugar break) are better than one. Several studies have shown that yeast will take up ~50% of their nitrogen within the first few hours of active fermentation, and that another addition at the 1/3 sugar break is very beneficial to yeast health (sorry I can't quote the studies specifically, but I know they are out there).
I like to feed as often as I can, sometimes 6+ additions, it is just part of my process. You have to find a process that works for you, then gradually adapt it to different situations.
Maybe some of the really experienced guys can chime in on their experiences, but it might be what works best for them, I think the consensus is try to front load a little and add at least two total additions, but they may have better answers. :)

fatbloke
07-08-2013, 02:46 PM
Equally, I haven't got the link for it but someone posted a link to an academic paper that focused on staggered nutrients......

From memory, it said about working out the total requirement then went on to explain that while there's no real standard, they'd established that you can front load the nutrients up to 85% of the total requirement. Now as I say, I haven't got the link (and I'm using my phone ATM) and that's from memory but I'd presume that they used a minimum of 2 additions.......

I also presume that they followed the Lallemand/Lalvin idea of not adding anything until there is signs of active ferment and that the yeast would have been rehydrated with a rehydration nutrient.......

Jim H
07-08-2013, 11:13 PM
Gents, that's very helpful. If one of you can find the link, it would be very informative.

rmccask
07-08-2013, 11:49 PM
I am still new at the mead making but after a lot of reading I am mostly following Hightest's staggered nutrient addition schedule. He does have a large portion of the nutrients added at the same time you pitch the yeast. Here is a link to it on his site: http://home.comcast.net/~mzapx1/FAQ/SNAddition.pdf

Here is also a link from his site to the BJCP Mead Study Guide which has another method of staggered nutrient additions: http://www.bjcp.org/mead/Mead_Study.doc

fatbloke
07-09-2013, 02:32 PM
I am still new at the mead making but after a lot of reading I am mostly following Hightest's staggered nutrient addition schedule. He does have a large portion of the nutrients added at the same time you pitch the yeast. Here is a link to it on his site: http://home.comcast.net/~mzapx1/FAQ/SNAddition.pdf

Here is also a link from his site to the BJCP Mead Study Guide which has another method of staggered nutrient additions: http://www.bjcp.org/mead/Mead_Study.doc
I don't know how much experimenting hightest actually did but his scheme has been reported as good by many people so likely worth following even if its not definitive......

ox45
07-09-2013, 04:20 PM
I also thought one of the risks of front loading all the nutrients is that it revs up the yeast too much and they burn everything up and cannot form properly. This leads to unhealthy yeast and a higher chance of stalling.

http://www.lalvinyeast.com/mead_nutrients.asp

Jim H
07-09-2013, 09:37 PM
Folks, this is really excellent information. The BJCP study doc has a lot of interesting information that will take some reading time. Ken S's Lalvin question was equally enlightening.

Thank you so much for digging up these links.

WVMJack
07-10-2013, 07:11 AM
Thanks for the links. WVMJ

mannye
07-10-2013, 10:37 PM
Equally, I haven't got the link for it but someone posted a link to an academic paper that focused on staggered nutrients......

From memory, it said about working out the total requirement then went on to explain that while there's no real standard, they'd established that you can front load the nutrients up to 85% of the total requirement. Now as I say, I haven't got the link (and I'm using my phone ATM) and that's from memory but I'd presume that they used a minimum of 2 additions.......

I also presume that they followed the Lallemand/Lalvin idea of not adding anything until there is signs of active ferment and that the yeast would have been rehydrated with a rehydration nutrient.......

Quick question: Would this (the part about not adding nutrient until active fermentation) also be true for "smack packs" as well since they are essentially rehydrated in a nutrient bath in the pack?

I would hate to over-feed and perhaps invite some off flavors...

fatbloke
07-10-2013, 10:56 PM
Quick question: Would this (the part about not adding nutrient until active fermentation) also be true for "smack packs" as well since they are essentially rehydrated in a nutrient bath in the pack?

I would hate to over-feed and perhaps invite some off flavors...
I doubt it. I'd suspect that they'd probably not be much DAP in a smack pack anyway.

If Lalvin have done research that gives the result that DAP at the earliest stages can be damaging to yeast cell development then I suspect that the other makers know that too.

There isn't, apparently, any DAP in GoFerm to cause that (possible/probable/alleged ?) damage. So without knowing their company secret I'd guess its like, just fermaid but without the DAP.

Either way, it still gives the yeast something to be getting on with so that there's enough "juice" in the yeast liquid so that it will show active ferment in something even as barren as a straight honey must so you can still get the main nitrogen source into the batch at the right time....

Hence it would seem most likely that the vial of nutrient in a smack pack is gonna be similar stuff.

Personally I've found them to be a PITA and can't justify spending 7 times more on the yeast than I do for a dry yeast......

mannye
07-11-2013, 08:53 AM
Personally I've found them to be a PITA and can't justify spending 7 times more on the yeast than I do for a dry yeast.....

They do seem to complicate the process a little more. Just now dealing with a dead pack because the heat of transport killed everything.

Jim H
07-11-2013, 10:18 PM
So, now that I have been a little enlightened to SNA's, I'd like some advice on its application to my current batch.

I have a sack that is currently underway. 3 gals, 12 pounds honey (total, added in stages), using K1V. (See the log here) (http://www.gotmead.com/forum/showthread.php?t=21557) While I was a good boy and fed it, I messed up the schedule. Of course.

What I did:

When re-hydrating the K1V, I added 1/2 tsp Fermaid K to the warm water it was suspended in. I have since read that this practice is a no-no. On the other hand, the yeast is obviously very happy and churning away vigorously 11 days later.
4 days later, I added "the remainder" of the planned SNA, 1 tsp worth. I added this in with a feeding of 2 pounds honey.


I should have reversed the dosage, with the 1 tsp shortly after pitching, and the 1/2 addition perhaps 48 hours later. Also, I should have made the nutrients 1/2 tsp F-K and 1 tsp DAP... but its only F-K.

I am guessing that I should leave well enough alone, and not add any more nutrient even though I may have given it too little DAP. After all, K1V is more robust than others, and I have put in plenty of Fermaid K.
- But, perhaps this does not provide enough DAP?
- Does the warmer temp range (80-93 F, so far, after 11 days) use up more nutrient?

Would you add any more nutrient at this point, or just leave it alone?

Jim H
07-14-2013, 12:08 AM
Well, after more reading, I took a chance. With my latest batch, when I added the last feeding of honey, I also added 1/4 tsp of Fermaid K. We'll see what happens.

fatbloke
07-14-2013, 02:10 AM
Don't forget, Fermaidk already has DAP in it.

When I was looking into this last, I concluded that a sensible mix was 2 parts Fermaidk and 1 part DAP so that the nitrogen content of the "food" was boosted but there was still enough of the other non-nitrogen elements too keep the yeast happy. Nothing scientific about that particularly but it seems to work i.e. at 110 ppm nitrogen from the F-K per gramme per litre and 200 ppm for DAP at the same numbers 2 to 1 will give me about 140 ppm nitrogen per gramme per litre.

Hence using the farmers mentality of making sure a crop has enough fertilizer to grow well but not enough to burn the young plants - using as 20-10-10 instead of straight ammonium phos, which gives about 42.5-0-0

Dunno if that makes any sense or not, it does to me and my warped little brain.

I'd guess using a 2 to 1 as above means its easier to work out how much to use.

There are some threads kicking around that suggest likely amounts depending on how strong the end result is likely to be so whether anyone has collated the data to say A yeast has a max tolerance of B so C to D would be the suggested amount for final alcohol concentration of E to F......

Jim H
07-14-2013, 10:02 AM
No doubt I've done it all wrong -- I will have to see the effect on my current batch. I've used no DAP, and I am relying on the DAP in the Fermaid K, alone.

But, most of the reading materials that have come out of this thread indicate 2x DAP to 1x Fermaid K. (FB - did you mean to reverse your figures? Or is that actually the proportion you use?) Even Lallemand makes that suggestion for low nitrogen musts. I found this pdf (http://morebeer.com/images/file.php?file_id=1205), spelling it out in detail.

Considering that I used K1V, and that I've given the must plenty of nutrients at this point, I will not be adding any more. It's producing plenty of foam after the last SNA and final honey addition. No off-smells.

Bob1016
07-14-2013, 11:13 AM
It seems that there are three rates that are common.
Some follow the legal limits, no more than 1g/gal fermaid K, and the rest of the YAN comes from DAP.
A lot of the other patrons on here have been suggesting a 70:30 ratio, or about 2:1 in favor of fermaid K.
Others have gone to all fermaid K, adding fermaid O, yeast hulls, boiled yeast, and other organic N sources.
All can make great meads, but your practices and techniques might work differen with each one. I say try them all on a known recipe and see what works best for you. Three one gallon batches are all that's needed.
K1V is great for meads because of the low N requirements, so as long as there is some nutrient it should be happy, but other yeasts will act differently.

Chevette Girl
07-21-2013, 02:00 PM
For fruit wines I usually follow the directions on the packages, 1 tsp per gallon for DAP and 1/4 tsp per gallon for energizer.

Since a straight honey must lacks a lot of the micronutrients and things, I usually quadruple my energizer and do a 1+1 tsp total.

If I'm doing a melomel that's lighter on the fruit, I'll go with 1 tsp DAP and 1/2 tsp energizer.

And I keep a nose on it, if my must starts making a stink, I will add more nutrients and/or energizer (depending on where we are in the fermentation, no more DAP after the 1/3 sugar break, and I'll use microwaved bread yeast past the 2/3 point)

I'm not terribly scientific about it but some folks do calculate out exactly how much nitrogen they need and make their additions based on that.

There are a number of folks who do use 2:1 Fermaid to DAP.

And don't sweat about doing it all wrong, when it comes to adding nutrients and energizers, doing something is still better than doing nothing. I didn't start using energizer until I was about five years into winemaking and I still turned out some pretty good stuff.

Bob1016
07-21-2013, 02:19 PM
And don't sweat about doing it all wrong, when it comes to adding nutrients and energizers, doing something is still better than doing nothing.

Exactly my point, just more eloquent! :)

Jim H
07-22-2013, 07:52 PM
Exactly my point, just more eloquent! :)

Yep. Lesson learned. Thanks, all.