To stir, or not to stir

[Deghisagorah]

I've read a bunch of articles and forums, some say you need to stir your wort for one whole week and wait for 1/3 of sugar drop before stopping.
Some say to not stir at all after a day has passed since you pitched.

And I stirred my mead twice a day, every day for 1 whole week since quite a lot of people suggest I should do that (and because I don't have a hydrometer, planning to buy one tho)
On the fourth day, I stirred and tasted my mead and it tastes quite sour, this is what I'm worried about because I know that oxidation can happen when you introduce too much oxygen into your wort.

Now I'm planning to make my second bigger batch of mead... Should I stir it or not?

Recipe of my mead: (pretty basic)
460ml Honey from the flowers of Kapok tree
2.7L of bottled water
Regular bread yeast (Fermipan brand)
Original gravity was around 1.100 (don't trust that number cause I measured it using a ghetto hydrometer)

Setup:
A plastic carboy (PET 10L water container)
A DIY airlock
Metal spoon (for stirring)

I know, I know its a really REALLY basic setup but its because I'm still a newbie, i don't want to spend a lot of money if at the end i wont be using the expensive equipments anymore

 

[CKuhns]

No need to worry about oxidation early in the ferment (roughly 1/3 break) Yeast go through two phases in their development. The first phase is called the aerobic phase. Yeast need air / oxygen to bud and reproduce effectively down to about the 1/3 break. In this phase your really trying to get the yeast to reproduce and to create get a huge colony of yeast that in the second phase (Anaerobic) consume your sugars and produce the alcohol we so desire.

With that said aerating at yeast pitch by aggressively shaking or stirring for a few minutes is desirable, i also believe a little air helps a couple times a day to 1/3 break.

The other benefit of stirring is you suspend the sediment (yeast and anything else that settles) Allowing for some of those yeas that have settled to get suspended and at the sugars as well. I gently swirl the carboy to 2/3 break without removing the airlock to suspend the solids.

 

[bernardsmith]

Hi Deghisagorah, and welcome.
Stirring has one additional benefit and that is it helps remove CO2. Carbon dioxide is toxic to yeast and the mead (or wine) we make is saturated with CO2. CO2 also acidifies the mead and honey itself is quite acidic. The acidification caused by CO2 (it can form carbonic acid in solution) is only a real problem if it pushes the pH down below 3.... but under normal conditions the pH might be around 3.4 or thereabouts and honey has no chemical buffers to control pH so oit CAN drop below 3 and that is a problem for yeast: it stresses the yeast and stressed yeast are very karmic. You stress yeast and yeast will stress you.
Good luck.