The Fresh Loaf

A Community of Amateur Bakers and Artisan Bread Enthusiasts.

Back to basics. A 100% hydration starter?? What does it mean?

Dave's picture
Dave

Back to basics. A 100% hydration starter?? What does it mean?

Hello everybody. So funny how sometimes you just need clarity on some of those first lessons that your learn, especially about starters. So here is my question:

Is maintaining a 100% hydration starting a 1/1/1 ratio. Being equal parts starter/flour/water?

So if I have 100g of starter I should feed it 100g flour and 100g water?

Or if I have 100g of starter, should I feed it 50g flour and 50g water, equaling the 100g of starter and taking into account the amount of flour and water that already exists in the starter. Being 50g flour and 50g water.

Reason I ask is because I have seen floating around on TFL this 1/1/1 ratio. So to me it would seem that if I use that ratio I am creating a 1/2/2 starter because I would be doubling the amount of flour and water to the original amount of 100g of starter.

Or am I just confusing myself?? HAHA!!

Cheers!

 

jcope's picture
jcope

Grams of water / grams of flour = hydration %.

If the system is always the same, then whether you do 100/100/100 or 100/50/50, you'll have 100% hydration starter.  The decision between the two seems to be a question of waste.  I have seen opinions, but no evidence, that 100/100/100 makes for a healthier starter: the ratio of new flour to old flour is 2:1.  In 100/50/50, the ratio of new to old is 1:1.  The latter is more efficient, assuming the health of the starter isn't any different.

Also in maintenance, I've found that feeding 20 of starter, using whatever ratios you want, seems to be enough.  There is no reason to keep 200 - 300 grams of starter around unless for some reason you aren't able to plan ahead and build up your starter quantity from a small amount systematically.

Dave's picture
Dave

Of course. I think I've got it now. As long as you feed your starter equal amounts of flour/water it will always be a 100% hydration starter. Also because you already have equal amounts of flour and water in the starter to begin with.

And I get that feeding it a 100/100/100 ratio makes for a healthier starter then a 100/50/50.

Brain fart! I think I already new this but totally forgot it! HAHA!

Thanks for filling me in jcope!

And I don't waste any starter with the recipe that I use. Those were just numbers I was throwing out there.

Cheers!

 

jcope's picture
jcope

"And I get that feeding it a 100/100/100 ratio makes for a healthier starter then a 100/50/50."

How do you get that?  I've read that here before as an opinion, but have never read any actual evidence to say one way or another.  Not that I really researched or anythin.  I will say that I've had zero issues with starter health at 100/50/50.  

Arjon's picture
Arjon

I haven't seen anything to suggest the former is better for your starter, although I think you'd have to feed 100/50/50 more often, assuming conditions are the same either way. 

jcope's picture
jcope

You may be right.  I feed at 2/1/1 two times per day.  If the feeding frequency for 1/1/1 is half as often, then there would be no difference.

Doc.Dough's picture
Doc.Dough

Remember that the growth rate, if constant, produces an exponential increase in the bacterial and yeast population, so that going from 2:1:1 to 1:1:1 provides enough food for only one additional doubling of the population which is about 90 min at typical room temperatures. However, the starter survives just fine as the availability of food declines and the net effect is to marginally adjust the ratio of LAB to yeast in the mix.

Doc.Dough's picture
Doc.Dough

A mature starter has a pH of between 3.6 and 3.8, and below a pH of 4.3 the growth rate of LAB is slower than the yeast.  As a result, if you don't add enough new flour to buffer the existing acid in the starter when you feed it, there will be almost no LAB growth even as the yeast growth resumes.  Over time, this discipline will deplete the LAB concentration in the starter which will reduce the acid production, which will eventually increase the pH, which will allow the LAB to again grow in number relative to the yeast. This new starter has less LAB and more yeast.  A starter is most stable when the feeding provides sufficient food to allow the LAB (which always has a higher growth rate than the yeast under optimal conditions at any temperature) to replicate until they produce enough acid to drive the pH down to 3.8 where they stop reproducing (but continue to produce acid), after which the yeast consumes the remaining sugars in the mix.

AlanG's picture
AlanG

http://www.thefreshloaf.com/node/6815/how-develop-sour-flavor-sourdough  This is from back in 2008 but there is some good discussion of ash content in the thread.  Also, here is a quick snapshot of the composition of rye, whole wheat, and white wheat:  http://rye.vtt.fi/chapter3b.htm   I'm still puzzled by ash content since it's based on combustion leftovers which are largely minerals.  I'll need to go back to some of the source literature on testing before I can weigh in further on the 'buffer' issue.  It may be a misnomer.

Doc.Dough's picture
Doc.Dough

Thanks for the link. It contains a very good extended discussion by some well respected members of this community, some of which bears on my question. It also reinforces the notion that higher ash content is the marker for better buffering capacity, but does not present any quantitative assessment (though it suggests that one might be carried out later). Measuring TTA with accuracy and consistency is non-trivial and I would prefer to find somebody else who has done it rather than do it myself.

Mini Oven's picture
Mini Oven

with TTA might be valuable to you. 

drogon's picture
drogon

I don't feed my starters as such - I top them up. So if I use 200g from the mother jar, then I mix 100g flour + 100g water and add that back into the mother jar - no matter how much is already there. (then the jar goes back in the fridge)

If I need more starter than the jar can supply, then I add double the starter in flour & water, so if I need 500g starter, I take 100g from the jar, add 200g flour and 200g water to make up 500g.

At all times its 100% hydration. (and simple math)

-Gordon

AbeNW11's picture
AbeNW11 (not verified)

Means equal eight of Starter, Flour and Water.

If you have 100g Starter and feed it 50g flour + 50g water then that would be 1:0.5:0.5 but your Starter will still be 100% hydration.

I wouldn't feed anything less than 1:0.5:0.5 as atleast the flour you're adding is equal to the flour in your Starter.

Good feeds make for healthy starters. Anything less then that many consider a poor feed as spent flour is building up.

I'm not so strict in weighing the exact amount of starter left each time. I never keep a lot of starter at any one time so I prefer to do preferments. My starter lives in the fridge and each time I wish to bake i'll take a little off and build it up to the levain I want. Then when my starter runs low i'll top it up with equal amounts of lour + water by weight invariably its equal to or more than what is left.

Dave's picture
Dave

Thanks for your opinions team!

Like I said, I just had a brain fart for some reason and couldn't grasp the whole ratio 100% thing. But now I got it!!

Cheers!

 

Doc.Dough's picture
Doc.Dough

While the EXAMPLE of 1:1:1 is OK, you probably don't want to really use that ratio for propagating a starter.

The way a refresh cycle works depends on the added flour buffering the acid in the starter up to at least 4.3 (and preferably >5.0) so that the LAB actually multiply up to a population density of around 10E7/gm before they produce enough acid to drop the pH to around 3.8 where they stop reproducing. Remember that the LAB have a growth rate advantage over the yeast at any given temperature under optimum growth conditions. When the LAB stop replicating they continue to produce acid and consume sugars.  In the mean time the yeast replicate more slowly but don't even slow down when the pH drops low enough to shut down the LAB.  They continue to grow exponentially until they consume the remaining sugars in the mix.

When you refresh your starter, you need to provide the right conditions to allow this process to go to completion or you will not end up with the proper ratio of LAB to yeast (about 100:1).  If you feed at 1:1:1 the LAB will not reach the desired 10E7/gm before they shut down and the yeast takes over to finish off the sugars. The result is not enough LAB to give you the acidity you expect from your SOURdough bread.

So I suggest a minimum refresh ratio of around 1:2:2 and if you want a 24 hr cycle use x:13:15 where x varies as a function of ambient temperature (x=0.1 @ 80°F and as high as 5 @ 62°F) and you adjust it over the course of the seasons.

Dave's picture
Dave

Which is why I guess your called Doc.Dough.

Thanks Doc! I actually do understand a bit of what you are explaining. Except for the 10E7/gm stuff, and your last paragraph. I'm just not familiar with these types of calculations.

It's definitely interesting what you are explaining for sure!

Cheers!

Doc.Dough's picture
Doc.Dough

10E7 is shorthand for a one followed by seven zeros (10,000,000). The yeast population is measured in terms of CFU (colony forming units) per gram of starter so 10E7/g is 10,000,000 colony forming units per gram of starter.  A colony forming unit will reproduce in culture so you dilute a sample repeatedly by factors of 100 or 1000 until you have a sufficiently sparse population that you can actually count the colonies under a microscope after they begin to grow on an agar plate. Bacteria like LAB are typically measured using optical density (OD) when grown in a defined media.

dabrownman's picture
dabrownman

Doc.Dough!  Couldn't agree more!  I prefer a 3 stage ,progressively larger, levain build over 8-12 hours that totals 1:7:7.  Now with the summer here (it was 99 F today) the 3 stages are 2 ,3 and 3 hours at 86 F starting with a 8 g  rye seed.  Works every time even when the 66 % hydration starter has been in the fridge un-maintained for 3 months:-)

Once again thanks for Ganzel data and your spreadsheet.

Happy Baking 

Heylo's picture
Heylo

feed back the same amount i took regardless of the amount that is left.

the starter's great.

 

drogon's picture
drogon

... simple to calculate and use, however I am making bread 6 days a week with it, so maybe that has something, but the times I've been away for a week, it's "just worked" when I've come back and carried on where I left off...

I maintain 3 starters in the fridge - wheat - used daily, spelt - used 3 times a week and rye which is currently only used once a week.

-Gordon

Dave's picture
Dave

...pretty well sums it up for me too Gordon.

Sometimes I bake 3 times a week, sometimes only once a week and sometimes not for 2 weeks.

I maintain a 100% stone ground whole grain rye starter. Love it!! I know it so well that even after 2 weeks of not feeding, I can feed it once and it's ready to go.

Cheers!