PDA

View Full Version : How critical is pH to mead/yeast propagation ?



magarcia12
12-10-2008, 11:22 AM
to All Mead heads.

My local beer/wine shop says all Meads should be around a pH of 3.5
for proper yeast propagation. Prior to pitching the yeast, my pH was 2.5, I added 4 tsp. of calcium carbonate to the must and waited five hours.
It went up to 3.7 so I pitched the yeast and two days later CO2 is bubbling like "crazy". Does anyone find this pH too tight. Do Melomel's differ from Pyments in the pH range, or is this issue strictly related to the yeast viability.

magarcia12

wayneb
12-10-2008, 12:02 PM
Hi! Welcome to "Gotmead?"

Your LHBS has given you one point of good information, but really they should have told you a bit more. All wine-like fermentations should proceed within a pH range that the yeast find acceptable. That generally is within the region of about 3.2-4.0. In fact, yeast can happily live at pH higher than 4.0, but so can a variety of spoilage organisms, so it is best to keep the pH at or below 4.0 to keep them at bay.

Yeast have adapted to be the "first in" on ripe fruits that begin to rot in the wild. Those fruits (esp wine grapes) tend to have juice that naturally falls in the 3.2 to 4.0 range.

Below about 3.2, the yeast themselves are subject to stress, and they don't do well. In fact I have seen evidence of yeast stress in musts lower than 3.4, so I usually shoot for 3.4 as the lower limit in my fermentations.

So if your must is within that golden range, your chances of a successful fermentation are increased.

Sounds like you hit the "sweet spot" of that range with your carbonate addition, and I'm glad to hear that your must is fermenting robustly!

Medsen Fey
12-11-2008, 11:05 AM
A starting pH of 2.5 is extremely low. Outside of lemons, I don't think I can recall ever having a must which was that low before pitching? Can you give us the recipe for what you are making?

Medsen

magarcia12
12-12-2008, 02:44 PM
A starting pH of 2.5 is extremely low. Outside of lemons, I don't think I can recall ever having a must which was that low before pitching? Can you give us the recipe for what you are making?

Medsen
Medsen,

At the time of pitching there was #15 honey, 64 oz. Pinot concentrate and a pint of grapefruit concentrate. magarcia12

magarcia12
12-12-2008, 02:49 PM
Hi! Welcome to "Gotmead?"

Your LHBS has given you one point of good information, but really they should have told you a bit more. All wine-like fermentations should proceed within a pH range that the yeast find acceptable. That generally is within the region of about 3.2-4.0. In fact, yeast can happily live at pH higher than 4.0, but so can a variety of spoilage organisms, so it is best to keep the pH at or below 4.0 to keep them at bay.

Yeast have adapted to be the "first in" on ripe fruits that begin to rot in the wild. Those fruits (esp wine grapes) tend to have juice that naturally falls in the 3.2 to 4.0 range.

Below about 3.2, the yeast themselves are subject to stress, and they don't do well. In fact I have seen evidence of yeast stress in musts lower than 3.4, so I usually shoot for 3.4 as the lower limit in my fermentations.

So if your must is within that golden range, your chances of a successful fermentation are increased.

Sounds like you hit the "sweet spot" of that range with your carbonate addition, and I'm glad to hear that your must is fermenting robustly!
Wayne B.

The ferment has appreciably stopped (after 60 days) and I have racked to another fermeter with two additional changes. Added six oak cubes and placed fermenter in 40 degree refrigerator. I intend to holdit there w/airlock for 60 days before botteling. This is a still mead. magarcia12

Medsen Fey
12-12-2008, 11:27 PM
Medsen,

At the time of pitching there was #15 honey, 64 oz. Pinot concentrate and a pint of grapefruit concentrate. magarcia12

I reckon that grapefruit concentrate brought the pH way down. How does this Grapefruit Pyment taste?

fatbloke
12-13-2008, 12:45 PM
I reckon that grapefruit concentrate brought the pH way down. How does this Grapefruit Pyment taste?
Whereas I was thinking it might have been both, as they're both described as "concentrate".

Surely by that, it's fair to guess that the reduced water level of a concentrate who have an increased level of acid.

I just like to make sure that I'm in the 3.5 pH region with a "pen meter" before I pitch the yeast

regards

fatbloke