when you add fresh or freshdried yeast to a starter there are billions which become 2x billions >4x billions etc
if the starter you use has only a few viable yeast it goes few>2 few>4few and so on until eventually you get to the billions point and then it only takes a couple of generations for lots.
a bit like epidemiology
in those terms yeast has an R2 and a doubling rate of about 15 mins at the optimum temperature/media for that strain,20 to25C is a fair bet for bread yeasts, wine a bit cooler.(they will grow faster a bit warmer but so will a load of unpleasant things and if there are more of them than the yeast they will dominate.
ie from inoculation with a small number of viable yeast most of the time to build up a useable population the mix will have very few active cells and will seem "useless" until enough generations have happened
it is the last couple of generations that you want for raising breads.
once you get one going, it is easy to use 3/4 for baking and dilute/feed the rest for next time or keep a blob of dough in a cold place and use that as a new inoculant for the next starter.
a nice thing with yeast is that Gt is very temp dependant, full speed at 30C and a Gt of 15 mins, at 10C Gt might be as low as 2 hrs and at 1C days or some will have "hibernated" ,they form a rather neat coating that protects the live bits and suspend their activities until times are better suited to their needs.
i have found life in some very unpromising yeasts that were well out of date, in open sachets etc.
sean Downsizer Moderator
Joined: 28 Oct 2004 Posts: 42219 Location: North Devon
Posted: Sat Mar 28, 20 4:29 pm Post subject:
Nah, gave ours ages and it really wasn't doing anything. Also none to be had in town.
when you add fresh or freshdried yeast to a starter there are billions which become 2x billions >4x billions etc
if the starter you use has only a few viable yeast it goes few>2 few>4few and so on until eventually you get to the billions point and then it only takes a couple of generations for lots.
that's a good point. might be worth persisting with elderly yeast.
sean Downsizer Moderator
Joined: 28 Oct 2004 Posts: 42219 Location: North Devon
Nah, gave ours ages and it really wasn't doing anything. Also none to be had in town.
dead at a guess.
a damp bowl, dusted with flour. outside will collect a variety of wild ones in a few days.
culture and select from there in.
I'm just doing these instead. Chucked some onion seeds, fennel seeds, cumin seeds and a splosh of olive oil in last night. Boy Wonder said they were a bit like Gareth's*. It's a nice scalable recipe too. 50g of flour makes one medium plate sized bread.
*They aren't a patch on Gareth's, he's just being polite.
Nicky cigreen
Joined: 25 Jun 2007 Posts: 9887 Location: Devon, uk
Posted: Sat Mar 28, 20 5:30 pm Post subject:
yeh i often make flatbreads, my favourite recipe uses yogurt, but you can make nice without.
I had fortunately ordered more at Christmas from Suma without realising I still had most of a bulk box left.
I'm posting out baggies of it (Doves farm fast acting) this week, pm me your address if you want adding to my list, reckon I could take another 5 or 6 people.
I need to decant it so it goes through the post, I'm not touching ANYTHING out there and definitely not going to the post office.
Shan
Joined: 13 Jan 2009 Posts: 9075 Location: South Wales
if olaf is sainted he will be available post permitting ( and i will make sure he can vent tidily in transit rather than swell up like a bovine hernia )
he is a very nice wild caught and selected by tweaks of his conditions starter
)
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