Stressed yeast?? Help!

[Ludesbrews]

Hey guys,

I am on my second ever batch of cider, and things aren’t going too well, or at least I don’t think they are.

The first batch of cider I made is almost done with primary fermentation. I used 1 gallon of 100% apple juice from Whole Foods, rehydrated 1/2 a pack of dry yeast, added sugars (4 oz of blue agave), aerated, abs pitched the yeast. The air lock started bubbling within a few hours.

The second batch is giving me a bit of a problem. I did the same exact thing that I did for the first batch, but I doubled the quantity of everything, and I have it in a 6.5 gallon bucket with an airlock. After 2 days I see no bubbling, but notice a “rotten egg” like smell. After some research one possible explanation may be that the yeast is stressed. Could this be the case? If so, what should I do? I thought about it and these are some of the options I came up with.

1- get rid of it, it’s ruined
2- rack the cider to 2 1 gallon carboys and go from there
3- add yeast energizer (nutrient booster)
4- add more yeast
5- aerate the cider
5- combo of any of these?


Thanks in advance for the help- I’d really like to figure this out!

Ludesbrews

 

[jodell]

I'm fairly new to ciders as well but have been brewing beer for awhile.
More than likely you are experiencing what we call rhino farts (sulfery-rotton egg smell). This does not mean the yeast is stress, rather this is a normal by-prpduct of fermentation. The smell will fade in a few days.

To prevent these in the future, add some yeast nutrients to your cider

 

[Ludesbrews]

Thank you- do you suggest I add the yeast nutrients now to the cider I have already made?

 

[jodell]

Probably not.

 

[Maylar]

Sulfur is indeed a sign of stressed yeast. Yeast need nitrogen, and when the available nitrogen in the juice runs out the yeast begin breaking down amino acids and extracting nitrogen from them - a byproduct of this is some stinky H2S hydrogen sulfide. Two ways to prevent that are to slow down the nitrogen consumption by fermenting at a low temperature (5 degrees makes a big difference), or using yeast nutrient up front. You can add nutrient (NOT energizer) now and it'll probably make the stink go away. A packet of bread yeast boiled in a 1/2 cup of water makes a reasonable nutrient if you don't have any DAP or Fermaid.

 

[Yooper]

And when you add the nutrient, stir it well. You want to get rid of the H2S.

 

[bernardsmith]

Yeah.. Brewers seem to have more tolerance for the yeast's production of sulfur dioxide than wine makers. True - some yeasts are notorious for their production of hydrogen sulfide even when not stressed but most yeasts that the OP is likely to have selected produce their rotten egg smells when the cider maker has failed to attend to their very simple and basic needs. Interestingly, a fermentation that is very active tends to blow off the gas while a torpid fermentation allows the gas to settle and make itself very well known to you. Whipping air into the must helps remove the gas as does introducing minute amounts of copper (the sulfur binds with the copper and releases the hydrogen to bind with with the oxygen). You can introduce the copper by racking the cider over some sanitized scrubbing wool found in the dish cleaning shelf of your supermarket. But nutrients are what the yeast are looking for and as Yooper says, stirring is important.

 

[Ludesbrews]

Thanks for all the help. When I got home the smell seemed to have went away, but still no bubbling in the airlock. I read up a bit before taking action and decided to check the SG. It was down to 1.040 from 1.062, so I am just going to let it be I think. I will test the SG in about a week again. How does this sound?

 

[Yooper]

Thanks for all the help. When I got home the smell seemed to have went away, but still no bubbling in the airlock. I read up a bit before taking action and decided to check the SG. It was down to 1.040 from 1.062, so I am just going to let it be I think. I will test the SG in about a week again. How does this sound?

Like the yeast is going very slow, and is stressed. It needs some nutrients, some oxygen, and to be stirred to get rid of c02.

 

[madscientist451]

What yeast are you using and what temperature?

 

[Ludesbrews]

Windsor ale yeast and it’s at a consistent 66* F

 

[Scrumpy!]

Toward the end of the turbulent phase of yeast growth, the yeast population is high and has likely consumed most of the nutrients available in the must. All of the above suggestions will help or even fix the problem. I take the same path as Maylar which is to slow the yeast growth down by lowering the temperature. This slows yeast reproduction which greatly reduces hydrogen sulfide production. If you get it low enough, you don't need to add anything other than time. In my opinion, slow fermentation makes a more full bodied cider and you may even feel a little virtuous by not adding any additional chemicals to your cider. Unless you are really flogging your poor yeast with high temperatures, that sulfur aroma will probably go away by the time your cider is down to 1.020 or 1.010. If the temperature stays high, you may need to treat it with copper sulfate or a copper dish scrubber to get the sulfur out of solution. If you wait too long to intervene, you probably will have to flush the batch. Do one of the interventions suggested now before it is too late.