I asked Mark Dennien our resident baking expert who has many years in baking behind him.
His response is as follows:
The activity in your ferment “half the flour to all of the water” would be impacted if the starch damage was low, and this is part of the milling process. Because the lower the starch damage the less sugars that are produced in the fermentation.
You could possibly fix this by adding a bit of either honey or sugar to feed the yeasts in your ferment.
Although some areas experienced heatwaves, if you search your flour’s batch number on our plate2farm tracker http://plate2farm.com.au you’ll see that its a blend of flours from different farmers who farm different areas of Queensland. This blending is part of the way that we ensure seasonal variations can be minimised.