The Fresh Loaf

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sourdough starter hydration percentage?

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tempe's picture
tempe

sourdough starter hydration percentage?

Hi All,


I am feeding my starter at a ratio of 1:4:5 (starter:water:flour) It just wasn't getting anywhere on a 1:1:1 ratio or even a 1:2:2 ratio.  It seems to be quite happy with this and is bubbling away when fed, but my question is if what hydration percentage is my starter? 


Maybe this is a dumb question so sorry if it is but for some reason I just can't seem to work it out.  Any help would be great. tempe

JeremyCherfas's picture
JeremyCherfas

After a couple of goes around your starter will be at 80%, 4 water to 5 flour. If, that is, you are measuring by weight rather than volume.


Jeremy

mrfrost's picture
mrfrost

Assuming the ratios are weights:


4 divided by 5 = 4/5 = .8


.8 x 100 = 80 %


Your starter's hydration is 80%.

tempe's picture
tempe

Wow, a quick reply - thanks very much Jeremy and Mr Frost. I will keep the math for future reference Much appreciated. tempe

Jeff Whatley's picture
Jeff Whatley

80% is correct, of course, but I am more concerned about why your 1:1:1 ratio did not work?  Done correctly, 1:1:1 should work fine.  If it doesn't work, then something is being done incorrectly.  In my view, the error(s) should be uncovered before camouflaging them with other replenishment ratios. What kind of water and flour are you using and at what temperatures?


Jeff

tempe's picture
tempe

Hi Jeff,


Thanks for your questions, I hadn't thought to question 'why' I have needed to use this ratio.


I have been using Laucke Wallaby Unbleached Bakers flour at room temperature which at the moment is about 25 degrees celsius and my filtered water at the same temperature.  I live in a sub tropical climate, Queensland, Australia, it is very warm and humid and will be until about April.  I take my starter out of the fridge and allow it to come up to room temperature before refreshing.


I take out 1 tablespoon of starter put in a clean container and then mix in 4 tablespoons of water, stir well, then add 5 tablespoons of flour and mix thoroughly.  With this warm weather it has been doubling in about 8 hours, in the cooler months where it is about 18 degrees celsius inside, it takes about 12 hours.


When I have tried this same method using the 1:1:1 ratio, nothing visible happened, it just sat there, no bubbles, no action.  Same reaction with the 1:2:2 ratio.  It seemed to smell more acidic the longer I left it,  it seemed to become more liquid and runny.


My usual practice is to feed my starter weekly even if I don't plan on baking with it that particular week.  I also check on it mid-week and it usually is ok with no smelly liquid stuff.


Thanks again, and I look forward to reading your response.


 

JeremyCherfas's picture
JeremyCherfas


I take out 1 tablespoon of starter put in a clean container and then mix in 4 tablespoons of water, stir well, then add 5 tablespoons of flour and mix thoroughly



This means that you are using volumes, not weights for your starter, and so all that stuff about 80% hydration is wrong. I never use volumes myself, so cannot advise, but someone will be along shortly, I'm sure.


Also, filtered water can be an issue, especially if is deionised water, but you are using the same water t different rates, so I don't suppose that is it.


Jeremy

Yumarama's picture
Yumarama

Just for fun, I've gone ahead and measured out five tablespoons of AP flour (lightly stirred, scooped then leveled) and I got 45 grams. I then measured 4 tablespoons of water and got 52 grams.


This then turns out to be 115% hydration.


Based on this, 6 tablespoons (9g each) would be 54 grams. Much closer, even if off a bit, to a 100% hydration if added to 4 tablespoons of water. And assuming that one's "spoonfulls of flour" are consistent, which I wouldn't bet on.

cranbo's picture
cranbo

measuring by volume is not the same as measuring by weight:




  • 1 cup of water is about 236g 

  • 1 cup of flour is about 125g (varies based on compaction & humidity)



This means 1:1 starter is actually about 189% hydrated. 


16 tablespoons in 1 cup, so 




  • 236/16 = 14.75g per tablespoon of water

  • 125/16 = 7.8g per tablespoon of flour



4 tbsp water * 14.75g = 59g
5 tbsp flour * 7.8g  = 39g


59/39 = 151% hydration for your 1:4:5 starter by volume.


 

tempe's picture
tempe

Thanks everyone for your input, it is welcomed. 


I'm sorry to say I didn't realize that it would make any difference whether I used weights or volume, I assumed that if I kept the ratio the same i.e 1:4:5 in tablespoons would be the same as say 1:4:5 using for example 10g:40g:50g. I now see from the figures provided above that it is not an accurate way to measure.  cranbo you mentioned that  1 cup of flour is about 125g varies based on compaction and humidity - it is very humid here mostly between 80 and 90%, how does this affect the flour? Does it moisten it therefore weigh more? I haven't lived very long in this climate, I spent 40 years in a temperate climate in another part of the country.


Also I need to mention that our Australian tablespoon measure is 20g or 20ml, why I don't know, so again I figured my ratio would be 20g:80g:100g.


So with this new knowledge, I think I need to review my methods and start measuring acurately and not using volume.  THis could be why my starter didn't seem to do anything on the ratios of 1:1:1 or 1:2:2 - inacurate measuring


So maybe I should start back with a 1:1:1 ratio (measured) and see how that goes.


Thanks again, I'm always willing to learn and grateful of any help. tempe

JeremyCherfas's picture
JeremyCherfas

Seriously, if you can find a good scale that will weigh in 1 gm increments, do get one. It makes things much easier, in my opinion. I have a simple electronic balance which converts easily between Imperial and SI and has a simple tare function that reduces the reading to zero, which makes it easy to add ingredients one after the other to the bowl.


Jeremy

cranbo's picture
cranbo

hi tempe,


Best way to check typical weight of your flour would be to measure out 1 cup and weigh it on a scale. The weight will change every time, and vary day to day. That's why measuring by weight is much more accurate. 


Yes, if it's very humid, your flour will weigh more (because it's holding more water).


 

tempe's picture
tempe

Hi cranbo, thanks for your reply.  The penny has dropped! Or the light bulb just came on, whichever you like but I get it now.  Just takes a little while sometimes!  Everyone here is so gracious sharing their knowledge and helping out those of us still with a lot to learn. Thanks again,  tempe

tempe's picture
tempe

Thanks Jeremy, I will see what I can find next time I go out shopping.  Thanks for letting me know what to look for too. tempe