Big Time Starter Expansion

Jo Bottrill appended this question to my birthday thread but it is well worthy of its own post.

“Hi Mick, I have been using your sourdough refresh method and scaled up and down versions of your recipes for my loaves – it’s all working a treat!  I retard everything overnight in my cold conservatory. (dread to think what to do when it warms up!!) Anyway, I am doing my FIRST farmer’s market in a week and a bit and I need to ramp up my wheat (white) sourdough culture to 7 kilos!  The plan is to increase my current starter in the fridge to about 200g (It’s about 100 at mo) and then remove 170 to do the following with:

Wednesday 6am – 1:2:2 (170 + 340 + 340) = 850
Wednesday 6pm – 1:1:1 (850 + 850 + 850) = 2500 (50 spare)
Thursday 6am – 1:1:1 (2500 + 2500+2500) = 7000
Thursday 1pm – the mixing begins! (I have the loan of a bakery to do this, phew!)

Do you think this will work all out of the fridge?  Or should I Put the Wednesday morning refreshment in the fridge and only get it out Wednesday evening?”

Hi Jo,

Couldn’t help smiling at your question – not laughing at you, you understand – it just reminded me of that mixture of elation and panic you feel when you are about to scale up your bread production for the first time.

Your plan should work fine but your final refreshment is a bit on the short side – 7 hours before mixing – I don’t know your starter but I would give mine at least 8 hours.

The other thing is, you’re obviously  doing everything literally by the book. The problem with writing a bread book, particularly a beginners’ book, is that you have to give very precise instructions that err on the safe side – trying to take into account all abilities.

By this stage I would imagine you probably bake at least a couple of times a week, even if that’s only a few loaves for yourself. If so, there’s no need to have your starter in the fridge. Rather than following my instructions precisely you need you use your eyes and nose to assess the state your starter is in. There’s a lot of scope for flexibility once you have your basic systems running.

Here’s a very bad example which I don’t recommend but illustrates my point. On Saturday I came to mix a couple of brioche and some wholemeal dough for pita bread. I looked at my starter and it was obvious I hadn’t refreshed it at all on Friday as I had thought so it must have been Thursday. I thought, sod it, the dough’s going to ferment in the fridge for at least 22 hours – that’s plenty of time for the little yeasties to get working. It all came out fine.

Yesterday I celebrated my first day of pensioner poverty by going out on the town(s), Liverpool and Chester, and having a bang-up lunch. I did refresh my starter before leaving home and I did persuade the owner of Lunya, Liverpool tapas restaurant and deli, to stock my book.

When I got home last night I was still sober enough to weigh my starter – 950g. This evening I need 3900g for a smallish mix so, according to the book, I should have 1300g of active starter for this morning’s refreshment. Sod it, I thought, being a man of limited imagination, and went to bed. This morning I refreshed my 950g starter with 1475g and 1475g which isn’t exactly 1:1:1 as the book says. It will all be fine.

So my starter lives in the kitchen at whatever temperature the kitchen is at. I neglect it, refreshing it every 2 or 3 days until I need to build it for dough making. I usually refresh it twice at 12ish hour intervals before mixing. I add 10% rye flour to my refreshments because it greatly improved it one time when flour quality seemed to have dropped.

What’s your bake schedule if you are mixing at 1.00 p.m.?

It’s worth buying a cheap fridge for overnight fermentation:

Exciting photo, I know. But it will take 6 large + 1 half-size boxes – more than 50K of dough. Then you need spreadsheet calculators for ingredient and dough weights and you can really sleep without panic attacks.

Good luck