smstromb

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I'm on my third day of fermenting a 5 gallon batch of orange mead.

OG (6/20) - 1.091
SG (6/23) - 1.080

The last couple of times I've done mead I didn't bother checking/adjusting my PH but I decided I'd have more control over it this time. My PH started at ~4.5 and I used 1/8 tsp of acid blend to bring it down around ~3.8. Today is day number 3 and it looks like my PH is down to ~3.3

I've been told that the best PH for mead to ferment at is ~3.8 is this correct?

Will going as low as 3.3 permanently hurt my fermentation or does it just slow it down? Will bringing it back up to 3.8 return it to normal or will the rest of my fermentation be effected?

How much chalk (calcium carbonate) would you add to a 5 gallon batch to bring it back up from 3.3 to 3.8?

TipsyDragon

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you really didn't need to add the acid blend. the PH was going to drop all by itself. mead should stay somewhere around 3.7PH. i would add a few tablespoons of calcium carbonate to bring the PH back up. as far as how much thats something your going to have to find out for yourself. i would add a tablespoon at a time and let it mix then take a sample and see what it's PH is. in my experience the PH stops dropping after about a week or so.

MedsenFey

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I usually find the pH drops to its lowest point within about 48 hours.

Some yeast can function okay at a pH of 3.3 and if your fermentation is proceeding rapidly, you may not need to do anything. Which yeast are you using? Can you provide the other recipe details?

When adding calcium carbonate, it doesn't dissolve into solution easily so you may want to wait a few hours between addition to let it equilibrate or you risk overshooting the pH and leaving it too high. Potassium bicarbonate dissolves more rapidly, but even then giving it some time to equilibrate is wise.

You do not need to move the pH above 3.6 as that will work well and the pH tends to rise a little as fermentation finishes and all the CO2 dissipates. The higher your final pH, the easier it is for spoilage organisms to take hold, so when adjusting pH, less is more.

__________________
"Our results are merely the result of carefully managing the transformation of bee spit into yeast excrement."
--- Wayneb

smstromb

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I'm using Lalvin D47 and the recipe details are similar to JAOM but with slight variation:

~4 Gallons water
15lbs clover honey
2 cinnamon sticks
100% orange juice to taste (~3 pints I'm guessing)
10g Lalvin D47

I added 1.5 tsp of high alcohol yeast nutrient while pitching the yeast. My plan is to add another 2 tsp at the 1/3 sugar break. The airlock is still bubbling away but just slower than my other meads.

MedsenFey

Recipes 

I wouldn't worry about the pH at 3.3. D47 is quite capable of fermenting at that pH and even lower so I would just let it go for now.

I'd just keep this at a lower temp than JAOM. D47 doesn't do well at temps above about 72F.

__________________
"Our results are merely the result of carefully managing the transformation of bee spit into yeast excrement."
--- Wayneb

biochemedic

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+1...acid blend really isn't so much for adjusting the pH as for adjusting the taste; point of fact, Ken Schramm doesn't recommend adding until after primary, or even at bottling.

+1 again...the amount you need to add to adjust the pH really depends more on the acid content than the pH...unless you do a titration you can't actually calculate how much carbonate you would need.

malkore

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Yep, never adjusted the acidity pre-fermentation and only once or twice post (at bottling).

the pH is dropping because the CO2 in solution is creating carbonic acid, thus the pH dips a little. as the CO2 comes out of solution the carbonic acid drops and the pH will rise again.

__________________
Malkore
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10

Kershner_Ale

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Michael Kiker, owner / operator of Celestial Meads, told me to monitor pH and start to buffer once it drops below 2.9 for most yeasts. He said generally speaking, if it's not below 2.9 he's not worried. Since he brought home 9 medals from this year's Mazer Cup Competition, I tend to listen to him

MedsenFey

Recipes 

A pH of 2.9 will stall some yeast, and it requires them to have a lot of potassium to compensate for the electrochemical gradient across the cell membrane. Some yeast are very tolerant of low pH and some are not so it depends on your recipe. Although there is no hard cut-off, I tend to start adjusting if the pH is below 3.2 in most cases.

The pH drop due to the CO2 is relatively minimal. Most of the pH drop in a mead comes from organic acid produced and secreted by the yeast during their metabolism (Succinic, Fumaric, etc.).

__________________
"Our results are merely the result of carefully managing the transformation of bee spit into yeast excrement."
--- Wayneb

Clifton

Recipes 

Can you use Sodium Bicarbonate to adjust the pH or will it lead to off flavors?