you may have seen the following phrase or a variation of the phrase floating around my blog posts.

“i have a stiff starter that’s 80% hydration. please adjust amount of flour in final dough to account for your starter’s hydration.”

you may have even wondered, “um *ahem* erica. more on this word adjust please.”

if that’s you, you’re definitely not alone. this post is for you, and i’m way more excited than i should be to talk about math and baking at the same time.

before i begin, a surprise

i know not everyone likes to nerd out on ratios. i’ve made a few cute calculators you can use to make things a bit easier and less manual at sourdoughcalculator.com

first things first

it’s important to know what hydration your sourdough starter is. an easy way to figure this out is to write down the amount of flour and water per feeding, and divide the water amount over the flour amount.

i usually feed my starter 30g of flour, and 24g of water. 24 / 30 = 0.8, meaning my starter is at 80% hydration. at 80% hydration, my stiff starter has a dough-like consistency.

many people feed their starter equal proportions of flour and water, meaning their starter is at 100% hydration. at 100% hydration, the liquid starter has a batter-like consistency.

let’s do some math

now the fun part (caveat: my fun might be much, much nerdier than your fun).

we can reverse calculate the amount of flour and water in our sourdough starter. because our sourdough starter is just two ingredients, and because the amount of water is just a proportion of our flour amount, our equation becomes:

amount of starter = amount of flour + hydration * amount of flour

this equation says, the weight of my starter is equal to the weight of the flour and water it’s made out of, and the weight of water is just a proportion of the weight of flour.

since we already know the amount of starter and our hydration, we can solve for the amount of flour.

a practical example calculation: if i have 100g of my stiff starter at 80% hydration, i can calculate the amount of flour by doing:

100 g = x + 0.8x

where x represents the amount of flour in my starter. when i solve for x, i calculate that my starter has 56g of flour, and 44g of water.

adapting recipes to your starter

so you have a 100% hydration liquid starter but want to make some of my recipes? i gotchu.

there are two cases to be aware of: one in which i’d recommend adjusting the amount of starter, as well as the amount of flour, and the second in which i’d recommend maintaining the amount of starter, and adjusting the flour and water.

let’s say you’re eyeing shortbread cookies, which calls for 100 g of starter discard.

100g of liquid starter means you have 50g of flour and 50g of water.

since the cookie recipe doesn’t call for water, i would first reduce the amount of starter to match the water content of my stiff starter, and then add additional flour to compensate.

we know that 100g of stiff sourdough starter has 44g of flour. therefore, i would probably use 88g of liquid starter (44g flour and 44g of water), and then add 12g extra AP flour (44 + 12 = 56g flour) to achieve the same flour:water ratio.

an example that has water are my fluffy scallion pancakes.

50g of stiff starter means 28g flour and 22g water.
50g of liquid starter means 25g flour and 25g water.

since this recipe includes flour, water, and starter, you can maintain the amount of discard, and directly adjust the flour and water content, by adding an additional 3g of flour, and subtracting 3g of water.

et voila

that’s all folks! if you want to see more of this kind of content, let me know.

in my opinion, you don’t need fancy or expensive tools to make good sourdough bread. it’s possible to start with zero (or very few) tools — i proofed my first loaf in a salad bowl and baked it under a tin foil tent (heh, true story).

however, nice tools will help you bake at a higher quality more consistently. from the experience of slowly building my collection to where it is now, i’ve learned that certain tools can, and will, significantly elevate your bread game, while some are just nice to have.

i want to show you that you can get your basic sourdough toolkit cheaply and easily, all sourced from your local grocery store, stuff you already own, or amazon. my hope is to help you start your bread baking journey as a beginning baker.

note for transparency: this post does have affiliate links to products.

the essentials

1 | high protein flour

ok, ok, so this isn’t really a “tool”.

however, flour is arguably the most important thing to bread baking — and for obvious reasons. the main ingredient in bread is flour, so there’s really no hiding. pay close attention to the protein content when selecting flour: look for a higher protein content, which will mean better gluten development. aim for something close to 12-13% (your run of the mill all purpose flour probably sits around 10%).

this doesn’t mean you have to break the bank getting high quality flour. i’m a massive fan of king arthur flour for delivering on quality while keeping prices affordable, and recommend it to any beginning bread baker. to start, i’d recommend keeping a bag of all purpose flour, bread flour, and whole wheat flour on hand.

3 | kitchen thermometer

we use so few physical ingredients when making sourdough — flour, water, salt. the magic comes together when we view time and temperature as ingredients as well.

a thermometer will help measure and control temperature like a scale helps control proportions of physical ingredients. the fact that these intangible concepts have such a strong effect on the flavor profile, texture, and success of a loaf still completely blows my mind.

in the world of kitchen thermometers, the thermapen reigns supreme. i have the thermopop, which is its younger sibling. just as powerful, a little slower, but way way cheaper.

2 | kitchen scale

if you’re an avid baker, chances are you probably already have one of these. volume is a pretty unreliable, inconsistent form of measurement compared to weight because when we measure ingredients, we are also measuring some variable amount of air.

you can make do without a scale and approximate using measuring cups, but your bread will become a lot more consistent and precise once you make the switch to a kitchen scale.

get a small one that has at least gram-level precision.

very strongly recommend

8 | dutch oven

my favorite part about a sourdough boule is the crust — thin, crisp, and chewy with a deep caramel color. this crust is produced by producing steam, which you can do a few different ways.

first, you can create steam by leaving either a cast iron with about a cup of water or a shallow dish of rolled, clean wet towels on the bottom of your oven. second, you can place your loaf in a covered dutch oven, which will naturally trap steam inside.

i find dutch ovens to be the easy, foolproof way for home bakers like me to achieve a bakery-grade crust without much effort. i recommend getting one that’s 5 or 6 qts, in either cast iron or enamel.

nice to have

5 | proofing basket

there are a many ways to proof dough without getting an “official” proofing basket. any large enough bowl-shaped item lined with a clean, floured tea towel, around 8-9″ in diameter and around 5″ deep, can serve as a proofing basket in a pinch. you can also DIY one for $2 with a basket from michael’s. these will all do the job!

buying one with the standard dimensions will run you $10-15.

7 | dough divider/knife

dough dividers serve two purposes: 1. to split dough in multiple sections if you’re making enough to make multiple loaves and to 2. help move dough from one area to another.

4 | lame

get a lame to add a decorative flourish to your boules! functionally, cutting the top of your loaf pre-bake isn’t totally necessary (especially if you’re going for a natural, rustic look), though it does help control where the air escapes.

6. silicone oven mitt

my favorite non-sourdough specific kitchen item. baking bread requires really high temperatures (close to 500 degrees farenheit) and these mitts help me effortlessly maneuver the dutch oven.

happy baking, and shoot me a message if you found this helpful!