My Daily Sourdough with Grape Starter

I needed to revive my grape starter (I dried it using the method here) to make sure that it is still alive and happy.  And indeed it is.  I dried it a month and a half ago because it was getting too strong and active and I couldn't keep up with it.  It took me 4 days to bring it back from its sleep and on the 5th day (yesterday) I mixed up a batch of dough.

This is the sourdough that came out of my oven this morning:    

My daily sourdough with grape starter  

                         The crumb           

My formula:  

150 g grape starter @100% hydration (my original grape starter was fed with 1/2 wholemeal and 1/2 rye meal before it was dried; but for this bake I used only white flour to revive it)  

320 g unbleached white flour

12 g organic honey

22 g olive oil

170 g water

8 g salt

oat bran for dusting  

(final dough weight 680 g and dough hydration 70.6%)  

After 3 hours of first fermentation yesterday during which time 3 stretch & folds were performed, it went into the refrigerator of 8 hours cold retardation, then it was shaped and stayed out at cool room temp (15 C/59 F) for another 8 hours before it was baked at 230C/450F this morning at 7.   

This is the first time that I've ever got a meaningful "grigne" in my sourdough.  The oven spring I got this time was phenomenal.  The dough expanded nearly double in the oven - first the whole dough raised up to nearly double its height, then the centre line along where the score was made further raised up to 2 + 1/2 times its original height.   

                    grigne                                                                                     

I was trying to think back what I'd done to deserve this oven spring.  It appears to me from the very beginning when the flour was mixed with the starter, the choice of flour and the hydration that was used for the particular flour, the way it was mixed, right down to its fermentation, and how the fermented dough was handled, everything has contributed to this.  I know many users at TFL in the past have commented that bread making is a continuous process and that every link in this circle matters.  This is the first time that I am cognisant of this process and witnessed its pleasing result when done properly.  

Well, let's not get carried away.  White flour is easier to achieve a holely crumb, right.

                                                                                 i am dreaming of a WHITE ... sourdough ....

 Shiao-Ping