Hmmm, so I did a bit of math.

Mixing 100g of flour and 100g of water, the final volume of the product came out to be around 110ml. This indicates that the density of this mix is 200g / 110ml = 1.82 g/cm^3
Since this is higher than water 1.82 > 1.00 it should definitely sink.

Be deduction, in order for the densities to be equal or less than water, it would have to increase in volume by at least 82%, or just shy of doubling in size.
Since most semi-serious bakers will have starters that almost triple in size, i would assume that just shy if doubling isn't quite ready yet. That goes well with your experiment where you said the starter would need a few more hours.

But if a 1:1 starter passes a float test, it has definitely grown a fair bit. So if the starter passes a float test, it at least can't be "dead".

• Reply