18 hours fermentation of Biga I am following Tony Gemignani's recipe for Pizza dough. For making a dough with a starter, he suggests making a Biga (which he calls "Tiga", link follows). Once the mixture is ready, he asks to let it ferment at room temperature for 18 hours. A few questions:


There is a connection between time, amount of yeast, temperature. Given that "room temperature" is not an exact measure, I guess that there should be some other measure of "when the starter is ready" and not specifically that 18 hours have passed.
18 Hours is really an inconvenient amount of time. If I start the Biga before going to work, that means I have to put it in the fridge in the middle of the night. If I start it later in the evening - I might be at work when it's time to put it in the fridge. So that's a really inconvenient schedule. I would prefer to use my fridge which has a constant temperature and have more control over the process and schedule.


Any ideas?

Thank you so much!

Master dough with starter: https://www.epicurious.com/recipes/food/views/master-dough-with-starter-51255340

Tiga: 
https://www.epicurious.com/recipes/food/views/tiga-51255350
1: Done is when you are happy with the result, less than 18 hours means less fermentation, more means more fermentation, it all depends on how much flavor you want to get out of it. 18 hours is approximate and as you say there are many factors. For a biga I'd use my nose, you will get a feel for when it is ready. Much more than 18 hours might get a bit strong.

2: Refrigerators are great tools for bread baking because they slow down the processes without stopping them or killing anything. You can ferment your biga/starter, or prove your bread in the fridge, it just takes longer. You could leave it out for 10 hours and then 16 in the fridge for example, or start it 2 days early and keep it in the fridge the whole time. A refrigerator is also very consistent in temperature, whereas room temperature varies from day to day

Keep in mind that the starter fermentation is about flavor development, and is an optional step. I always use a starter (a starter is a biga you don't ferment, you use it to get a good, healthy base for the rest of the dough) when making pizza dough but I rarely ferment it and I still get excellent results. Often I will make the dough and then refrigerate it for a day, I get the flavor development later in the process. So if you have 6 hours you can ferment the biga do it for 6 hours, it's not critical.