SG/ hydrometer questions

Emerald · 02-07-2010, 06:08 PM

Well after trying to search and read up on SG's and such- I can't find the answer to my question-
I just started a white grape/peach mead and took a SG of 1.158 and the temp was just 70 f. Is that kinda high? And will it kill off my yeast? Or have I just made peach flavored jet fuel?
one gallon white grape peach mead
3 cans of white grape/peach concentrate(thawed and airated for 24 hours)
2lbs honey clover
1/2tsp. yeast nutrient
1.5 oz raisins
1/2 gallon white grape/peach juice to fill (all but about 1/2 cup used)
ec-1118 yeast used.
The yeast looks like it is forming little colonies now.
But this is my first attempt to check the SG - I have forgotten to on most of my batches, and have so far, only used it to make sure that they have fermented out.
it tasted super sweet and peachy.

badmajon · 02-07-2010, 06:35 PM

Hi, I'm no expert but I have read a bit, 1.158 won't kill your yeast it just means you have a good amount of sugar in your must.

I don't think specific gravity will kill yeast at all... can someone confirm or deny this?

Oh and I just started a batch yesterday with an OG of 1.154, and its a full blown yeast orgy in there.

MedsenFey · 02-07-2010, 06:52 PM

A gravity of 1.158 isn't going to kill EC-1118. It is going to stress it. That means more volatile acidity and acetic acid production and more harsh flavors (and possibly odors). And yes, you are going to get peachy rocket fuel, but with age it may become something nice. Just plan to be patient.

It is possible for the osmotic pressure to be so high that yeast cannot function and essentially are choked. That level is somewhere around 500-550 g/L of sugar (a gravity above 1.190). At levels between where you are and this level it is hit or miss, and even when the yeast get started, they often poop out prematurely.

The temp of 70 F is okay. You are light on nutrients - very light. High gravity batches need a lot more than normal batches (like double).

I hope that helps.

Medsen

badmajon · 02-07-2010, 06:55 PM

Hmm, well then I'm in the same boat as him, my OG was 1.154 and I'm going for Ken's Ginger Mead (http://www.homebrewtalk.com/f30/what-gets-ready-fast-155685/index2.html), I just followed the recipe though... should I change the nutrient regimen?

Emerald · 02-07-2010, 08:23 PM

Thanks for the answers-- I was planning on adding more nutrient in stages, and I was worried for no reason- it has only been a few hours now and while I didn't think I would see much, it appears to have started making those nice globby yeast colonies and they are slowwwwwly moving in the must, but like the other meads that I have done, there seems to be a layer of thicker "stuff" on the bottom of the jug-- I think that it is just the honey (I just warmed it in a sink of hot water so that it would come out of the bottle better) settling and not being mixed in as well as I thought. It usually is gone in a few days as the yeasts really start to go.
Being a mead I am already knowing that it will be a year or more before drinking, I am just stocking up!

I have Apfelwein that will be done quicker, so I am not tempted..

Emerald · 02-13-2010, 02:28 PM

just a quick update- the ferment is in full swing and so far there have been no off odors from that corner, so the amount of yeast nutrient must have been ok. In fact all three of the gallon batches are perking right along with no off smells (not like the lovely rhino farts of the apfelwein

) and these are the first three that I have ever used the Y. nutrient in and they seem to be more consistent in the perking than the first batches that I have made. Yeast Nutrient is so inexpensive I plan on using it all the time.
Thanks for all the advice everybody. It's nice to know that people here are so helpful!