Spreadsheets and Seed Culture

Thus is how I look at it - it's either wet or dry - choose one and don't worry about it.

This is the Phazulator (right click and download - it's excel spread). The seed is dry and added as such, if there's a soaker as they call it, it's wet and also added as such. Everything is also calculated as such. Bakers math says a % of total flour, so that's what you get, but you have the option to add a % in a preferment, all is added to total weight as that's what a total weight is - the total weight of the project. Everything is changeable, and changing anything changes everything. To the right are cells you can use to track changes .

I remember kinda doing something with a spread with you a assume back (years maybe) but never got back to it - golf. Golf season is now done, I was bored, saw more posts on spreads and decided to whip this up. 20 minutes to do the math - 5 hrs cuz I didn't like the look and flow and kept changing things - can ya tell I was really bored

Enjoy! Oh - did I mention phone friendly

I never treat the seed culture that way in my calculations.  Here's my reasoning.  Doing so implies that your levain has the same composition and hydration as you propagated starter.  More often then not this is not the case.  For example my starter is 100% and fed with a blended flour, my levains are rarely at 100% and never use the feeding blend. 

It also implies that the starter and levain do not exist simultaneously - all your starter goes into levain and does not exist until you take out a new seed.  This makes a ton of sense for baking on a scale, particularly in a bakery with a continuous cycle, as it allows to reduce waste and cut back on the number of containers.  At home, my feeling is, it is much safer and easier to branch out and build levain separately - posts that start with "Help!  I accidentally..." are a testament to that.

Finally, there's an issue of "precise hydration".  The way I see there are two ways to achieve that.  Either you run everything in one pot, without ever transferring enything from bowl to bowl, or you calculate everything with 5-10% safety margin to account for transfer losses.  First way is not always convenient - a 60% sponge will crust over if left for 12 hours in a 6L mixer bowl.  The second way is wasteful, and the calculation becomes too complicated.  So, my way of calculating things is to include starter in levain/total dough, and treat each subsequent stage not by weight but as all of it, with the understanding that there will be transfer losses and the hydration will be a tiny bit different from the calculated, as it will be in any case due to fermentation losses.