How to know when primary fermentation is over when speed is slow (Wild fermentation)

[Bertramhage]

I put over a batch of mead now a month ago with good quality local honey and added some raisins and prunes for nutrients. I’m doing a wild fermentation without any added yeasts or sulfites. It took a bit for fermentation to start but is now bubbling - however slowly. I’ve read from other sources that this is not necessarily an issue as slow fermentation can have some perks and also that you can’t judge fermentation only on bubbles. My question is, however, how do I know when the first fermentation is over? I could take a hydrometer reading but wouldn’t that be a huge risk as the fermentation is slow and thus I might expose the mead to too much air by opening the container? My initial sg was 1.075, the temperature is around 14-15C, and it’s currently “burping” around every 2-3 minutes. What should I do here.
TIA!

 

[Maylar]

Oxygen exposure at this level has no risk. You need to test it with your hydrometer.

 

[bernardsmith]

Hiya Bertramhage - and welcome.
Honey tends not to be very susceptible to oxidation at the worst of times but while the yeast is likely to be pumping out CO2 the likelihood of oxidation is so small that you can ignore it. Seasoned wine and mead makers (unlike brewers) tend to use buckets as their primary and have the bucket loosely covered with a cloth and leave a bung and airlock to the secondary... That's how anxious we are about oxidation in the primary.

 

[RPh_Guy]

how do I know when the first fermentation is over?

The only way to know is by measuring s.g.
Just leave it alone.

BTW dried fruits often contain a LOT of sulfite. An actual yeast nutrient would have been a better choice.

Oxygen exposure is potentially problematic with a very slow wild fermentation. There may be excessive production of acetic acid or ethyl acetate.

 

[JP Smajda]

I put over a batch of mead now a month ago with good quality local honey and added some raisins and prunes for nutrients. I’m doing a wild fermentation without any added yeasts or sulfites. It took a bit for fermentation to start but is now bubbling - however slowly. I’ve read from other sources that this is not necessarily an issue as slow fermentation can have some perks and also that you can’t judge fermentation only on bubbles. My question is, however, how do I know when the first fermentation is over? I could take a hydrometer reading but wouldn’t that be a huge risk as the fermentation is slow and thus I might expose the mead to too much air by opening the container? My initial sg was 1.075, the temperature is around 14-15C, and it’s currently “burping” around every 2-3 minutes. What should I do here.
TIA!

Is this your first time doing a wild ferment?

 

[aimeecooper1]

I’m working on a second year of wild fermented mead with a two Tbsp add of sourdough starter a few days into primary fermentation. I use a crock for weeks 1-2 before moving to a carboy for months 2-4 and then checking for re-rack before bottling around 6months. There’s very little problem with oxidation since honey is really forgiving . Lasts years’ recipe used 1 orange, raisins and lavender from the yard in a 2lb honey to 1gal water mix. Lasts years mead ran 5%ABV at 6months and was delightfully semi-sweet with lemony undertones ..no sour flavors at all. We drank it all over the holidays

 

[bernardsmith]

I’m working on a second year of wild fermented mead with a two Tbsp add of sourdough starter a few days into primary fermentation. I use a crock for weeks 1-2 before moving to a carboy for months 2-4 and then checking for re-rack before bottling around 6months. There’s very little problem with oxidation since honey is really forgiving . Lasts years’ recipe used 1 orange, raisins and lavender from the yard in a 2lb honey to 1gal water mix. Lasts years mead ran 5%ABV at 6months and was delightfully semi-sweet with lemony undertones ..no sour flavors at all. We drank it all over the holidays

I gotta think that using sourdough starter as "barm" is complex. Sourdough is not simply yeast plucked from the air. It's also lacto bacteria (that's what gives the bread a tangy sour taste) so you are in fact making a sour mead (think sour beer). That doesn't mean "sour" as in "tastes bad" but lemon is sour and yogurt is sour and sour dough bread is ... um.... sour. And last year I often made gallon batches of mead where I dissolved the honey in rejuvelac - a beverage made by sprouting (malting) 1 C of wheat berries (or other grains) for 3 or 4 days (until they produced roots of about 1/3 of an inch long) and then covering the sprouts in about 1 gallon of spring water for another 3 days. By that time the grains would have shed a large amount of lactic bacteria into the water and the pH of the water would have dropped to about 3.4. The sprouts would have enough bacteria gorging on them to allow you to add another gallon of water and so produce a second rejuvelac from the same grains after another 3 days.

 

[RPh_Guy]

It's also lacto bacteria (that's what gives the bread a tangy sour taste) so you are in fact making a sour mead (think sour beer).

Lactic acid bacteria don't make wine sour.
... And she already said it wasn't sour:

no sour flavors at all.

The pH of wine is too low during yeast fermentation for the LAB to be able to grow and produce acid.

a beverage made by sprouting (malting) 1 C of wheat berries (or other grains)

On the other hand, beer, milk, and bread dough sour because they have a much higher pH (and buffering capacity), which allows the LAB to produce acid.