How much can you knead a dough, timewise?

...kneading for too long and having the yeast die...

Huh? Can you point at a reference that suggested this possibility? Something new for me to learn; I haven't heard much about kneading harming yeast before.

I know bread yeasts are sensitive to temperature: below about 40F they go dormant, above about 120F they die. I know they like food (such as flour). I know they dislike drowning in their own wastes (to them CO2 isn't food:-). And I know they're somewhat sensitive to some common flavorings and spices, such as sweetness and cinnamon. I've never worried about anything else though.

Hi Wek,

The answer to your question is really that it depends on a number of factors which will determine the rate at which certain changes take place within the dough as it develops and then proves.

So if you are working with a dough containing a lot of bakers' yeast and a bread improver, and working in a warm environment with dough reaching temperatures of around 28*C, then your time window is not long.

At the other extreme, if you have a slightly green levain as the sole means to raise the bread, or it is included in the formula at a relatively low rate, and the dough is mixed quite cool, then you have a lot more time before the dough rheology, or change, kicks in.   Some enzymatic reactions kick in as soon as the dough becomes hydrated, but the zymase complex is very much based on the activity of yeast on available sugars in the dough.

Whatever the circumstances, however [the 2 above are extremes at the end of each spectrum], intensive mixing of any kind may not be the best means to develop the dough once it is fully hydrated and the yeast reactions are kicking in as these enable a lot of enzymatic reactions as well.

I have 2 alternative suggestions for you.   The first is to use the French technique, known as Bassinage.  This means holding back a portion of water to enable you to mix and develop the dough properly first.   Only once the dough is developed do you then super-hydrate the dough.   It is not an easy method to practice, but, once I realised that the super-hydration in ciabatta-type doughs was preventing dough development in the mixer, I saw the logic of the technique.   Daniel Wing gives discussion of it in "The Bread Builders" pp.9-10, if you have that book.

Your other option is to rely more on the "stretch and fold" sequence during bulk proof.

I don't know where you are based, but maybe the flour you use is too strong, hence you struggle to get full development.   European Continental flours are not very strong, and produce dough which is extensible in character, and not so elastic as dough  produced using flour from North American strong wheats.   Maybe you could incorporate some weaker flour into your dough?

Best wishes

Andy