Hydration

Hello Sally,

The hydration of a starter/culture/levain/chef is just the weight of liquid (be it water/milk/oil) expressed as a percentage of the flour in the mix.  So, if a mix contains 500g of flour in total and 350g of liquid, then the hydration is 70% (ie 350 divided by 5).

In your case, the answer depends, slightly, on what the hydration of your 130g of starter but on the assumption that it is the same as the mix used to build the levain (a french term for the source of yeasts and bacteria that you use to mix into your dough and usually stiff or dough like) then it is 50% (obtained by dividing 95 by 1.9).  Using that figure, the hydration of the dough works out at 65%.  In the sponge (another term that is as equally valid as levain though usually thought of as having a higher hydration than a levain and more like a batter) there is 120g of water and 240g of flour which, with the fresh flour and water that you add gives a total mix of 390g water and 600g flour.  Dividing 390 by 6 gives you the answer of 65% hydration.  If you look up my list of blogs there is a link to a spreadsheet that you can download and use for calculation if you wish.

As for the correct words, what does it really matter at the end of the day as long as the bread is good.  If you do want more precise 'accepted' definitions of terms such as sponge, levain, starter, chef, poolish, biga etc then there are glossaries of sourdough terms out there on the web (possibly even on this site).  Here is just one selected more or less at random and not necessarily sacrosanct in its detail - http://www.brasseriebread.com.au/sourdough/sourdough-glossary.aspx

Good luck with your projects.

Farinam