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Terminology: inoculation

SoulDreamer's picture

Terminology: inoculation

This is probably a case of “too many cooks spoiling the broth”. In articles and recipes I have come across contradictory definitions of inoculation rate and I hope to settle it once and for all with the aid of the experts on this forum. 

What exactly is the inoculation rate?

To make my examples clear, I will refer to a hypothetical situation where 500g of flour is inoculated with 100g of starter with 100% hydration. 

Which of the following (A, B, C, or D) are correct?

A: The inoculation is 10% because there is 50g of fermented flour to 500g of unfermented flour. This is what I always assumed was correct.

B: The inoculation is 9.09% because there is 50g of fermented flour to 550g of toral flour. 

The following two definitions sound bonkers to me, Bu I’ve seen these definitions peddled as truth so I include them anyway:

C: The inoculation is 20% because there is 100g of starter to 500g of unfermented flour. This is a highly risky definition because if readers have starters that are NOT 100% hydrated, they will achieve different results.  Two bakers with a 75% and 150% hydration rate in their starters will produce different doughs than a baker with 100% hydration if using this definition.

D: The inoculation is 18.18% because there is 100g of starter to 550g of total flour. This, to me, sounds equality crazy than definition C, for the same reasons. 


Id be greatful if someone could help settle this. Is it A, like I suspect, or am I wrong?



gavinc's picture

My levains are inoculated with seed culture depending on the temperature and time before I need it ripe for use. Eg., I inoculate 20% seed culture to 100% flour at 21C if I want the levain ready in about 14 hours. If the temperature is 24C, I only use 10% seed culture to be ready in 14 hours. Inoculation is the amount of seed culture you use to elaborate the required about of levain given the temperature and time delay to ripeness.



Abe's picture
Abe (not verified)

It's 100g starter to 500g flour. However you wish to understand it whether it's 20% or 10% (due to the starter having 50g flour prefermented if 100% hydration) or any other way the fermentation time will be done whenever the dough is ready. Don't get too bogged down on the differences in terminology and watch the dough. 

  • In my mind for 100g starter @ 100% hydration it's 20% starter 
  • aka 10% inoculation due to 50g fermented flour to 500g flour 
  • aka 9% prefermented flour : total flour being 550g and 50g prefermented

But at the end of the day it's just different ways of saying the same thing and 100g starter to 500g flour at 100% hydration will take however long it takes which ever way you think about it. Eventually you'll get a feel for roughly how long one should expect it to take but always watch the dough.

Recipes do specify what the hydration of a starter should be and this is also where building a levain comes in handy so however you keep your starter you'll end up being very close to what the author is asking for. Should my starter be 50% hydration and the recipe asks for 100% hydration then I'll go for the same amount of prefermented flour if I just wish to use my starter and add that extra bit of water into the final dough.

SoulDreamer's picture

Thanks for the detailed answer. 

I should perhaps have clarified in my original question: 

I was not asking the question because I was unsure in how to follow recipes. I have a number of breads in my arsenal perfected, and I want to codify them on paper, in a scalable format. 

Before I did so I wanted to ensure I had the terminology down correct. 

From your answer I have decided to continue to define inoculation as fermented flour as a percentage of unfermented flour. 

Ilya Flyamer's picture
Ilya Flyamer

Just specify it explicitly, for example state PFF, and hydration of the levain. Then the is no room for error.

mwilson's picture


Inoculation isn't really a baking term and therefore there isn't a strict answer.
B is the same as pre-fermented flour and this definition has more specificity and really is the most suitable way to track "inoculation" because it eliminates the hydration variable.

The word ‘Inoculation’ is most suited to describing leaven and starter builds rather than the final mix.

PS: Also see my calculator [LAB Calculator | The Fresh Loaf] where I use the word

gerhard's picture

a thinker. Rarely weigh the amount of starter but it will be somewhat less than a 100 grams and add it to 300 grams of water, 240 grams of water which will then go on to infect 500 grams of wheat flour and a 100 grams of rye and another 300 grams water.

suave's picture

I don't want to get into the conversation about what (or, more importantly, who) is right or wrong, but I think you'll discover that the one of the more common, if not the most common ways of expressing feeding rates is X:Y:Z, for example 1:4:4, where X is the weight of the starter, Y is the weight of the flour, and Z is the weight of the water.  I guess this translates to C.