Mead Won't Start

[wreboot]

Start off recipe:

Lavin D47 yeast
3.75 lbs honey/gal
1 cup fresh citrus juice/gal (orange, grapefruit, and lime)
2 tbsp citrus zest/gal (orange with orange and so on)
1 tsp yeast nutrient/gal
1/4 tsp Potassium Metabisulfite /gal
Water

I was ambitions and was making a 15 gallon batch with some friends. Pooling resources and all that. We had 2 5 gallon carboys with 5 cups orange juice, 3 1 gallon carboys with 1 cup of orange juice, 1 lime and 1 grapefruit. In addition I added 1 tablespoon of hibiscus to one of the orange juice 1 gal carboys. I mixed everything together making sure that I dissolved the honey and added the sulfite. I aerated, then pitched. 13 of the 15 gallons have started and have been aggressively fermenting.

The two that did not start are the hibiscus and the lime 1 gal carboys.

2 have not started. I talked to my local homebrew shop and they suggested I add more yeast. So I did. Still nothing. I took a little more than 1 cup of must out of both and added water thinking that maybe I could dilute any sugar or acid tolerance that might be affecting the yeast. Pitched again and still no reaction...I don't have ph strips but I think that's probably the issue.

Any thoughts or comments? Anyway to save the 2 gallons of must I have?

 

[MajorJC]

Are you equating the absence of bubbling in the air lock to an absence of fermentation?

Is is possible that there is an air leak somewhere, like a crack in an airlock or a bad rubber seal that prevents the air lock from bubbling. Do you see any other signs of fermentation like bubbles or foam on the surface?

 

[Maylar]

A couple of things that I see -
1) 1/4 tsp metabisulfite is enough for 5 gallons. Your yeast won't like that. With that recipe, you didn't need any.
2) The citrus will lower the pH, and yeast don't like that either.
3) That's a lot of honey. With that high a starting gravity, the low pH, and all that sulfite I'd be surprised that any of them started.

 

[piojo]

You can use up the sulfites by adding oxygen. There are some suggestions here:
https://www.winemakingtalk.com/threads/help-too-much-k-meta.37964/

In short, do the same sort of things you would do to aerate the must. After using up the sulfites, you can pitch more yeast. (If the sulfites are the problem.)

Is it too acidic? I'd invest a buck in some pH test strips to always have on hand. If it is too acidic (pH at perhaps 4, but I don't know the exact number), partially neutralize it with potassium carbonate, potassium bicarbonate, or potassium hydroxide (be careful with this).

 

[bernardsmith]

Most yeast can handle a pH of 3.0 but being able to handle acidity is not the same thing as fermenting stress free. The trouble with honey is that honey has no chemical buffers to control acidity so even at the best of times the pH of a mead can scrape the floor. In mead making, you really want to add any acidity to the secondary and allow the yeast to ferment happily in the primary.

 

[wreboot]

Are you equating the absence of bubbling in the air lock to an absence of fermentation?

Is is possible that there is an air leak somewhere, like a crack in an airlock or a bad rubber seal that prevents the air lock from bubbling. Do you see any other signs of fermentation like bubbles or foam on the surface?

No activity. No foam no bubbles.

 

[wreboot]

You can use up the sulfites by adding oxygen. There are some suggestions here:
https://www.winemakingtalk.com/threads/help-too-much-k-meta.37964/

In short, do the same sort of things you would do to aerate the must. After using up the sulfites, you can pitch more yeast. (If the sulfites are the problem.)

Is it too acidic? I'd invest a buck in some pH test strips to always have on hand. If it is too acidic (pH at perhaps 4, but I don't know the exact number), partially neutralize it with potassium carbonate, potassium bicarbonate, or potassium hydroxide (be careful with this).

How will I know if I've used up the sulfites? I thought they used themselves up after about 24 hours...

 

[wreboot]

Most yeast can handle a pH of 3.0 but being able to handle acidity is not the same thing as fermenting stress free. The trouble with honey is that honey has no chemical buffers to control acidity so even at the best of times the pH of a mead can scrape the floor. In mead making, you really want to add any acidity to the secondary and allow the yeast to ferment happily in the primary.

That's for the tip I'll try that next time.