The hydration of enriched doughs

From that title, you’ll probably be able to tell if this post is for you. There’s no two ways about it: it’s one for bread geeks.

It was the feast day of Santa Lucia on 13 December, and I made my Santa Lucia crown, pictured above, with ravening children. This is an enriched dough, flavoured with saffron, made into a ring shape with two braids, and decorated with icing, sprinkles and candles. The sprinkles aren’t exactly traditional, but it’s what my kids like.

Making it, I felt my recipe still wasn’t quite right. The dough made for a delicious cake, like a super-brioche, but it was a bit soft and didn’t hold its shape well when braided and formed into the ring, or crown, shape. This got me wondering about the hydration of the dough.

Hydration and bakers’ percentages
Dough hydration is the proportion of water to flour, expressed as a percentage. So my standard loaf is made with 750g of water to 1000g of flour: that is, 75% water to 100% flour or 75% hydration (750 ÷ 1000 x 100 = 75). With the Santa Lucia crown, it’s 250g liquid (water and milk) to 500g flour, so I just kinda vaguely assumed it was about 50% hydration. But it’s obviously not as it’s so soft and sticky, due to the eggs and butter, and their water content.

Professional baking recipes use bakers’ percentages* along these lines for all the ingredients. This means giving the proportion of the different ingredients as a percentage of the flour (eg 6g salt to 1000g flour is 0.6% salt; 6 ÷ 1000 x 100). I used to include bakers’ percentages on some of my recipes (eg this challah recipe), and I thought I’d done a whole blog post about them, but I can’t find it, so I guess not. Maybe another day. If you really get into baking, and then really get into percentages and hydrations, you’ll be able to find all sorts of resources online, spreadsheets and calculators and whatnot.

Basic, real bread, is of course just water, flour, salt and yeast, so working out the hydration is easy. But how does the hydration work with enriched doughs? How do you work it out when the recipe includes not just flour and water (and yeast and salt) but also milk, butter and eggs? Working out the bakers’ percentage of milk in a recipe isn’t the same as knowing the percentage of water in that milk. So working out the hydration of the dough is another level of complexity. Read on.

Wondering about how my Santa Lucia crown dough handled also got me thinking how it compared with my brioche recipe, a quintessential enriched dough, and whether I could tweak the former so it’s more manageable like the latter. So here’s an attempt to compare both doughs: by doing their bakers’ percentages and working out the hydrations. I’ve probably lost readers who aren’t bread geeks by this point.

Fats, colloids and water percentages
So. Water is obviously 100% water. But what about milk? Vaguely remembering my O-level science, cow milk is a colloidal suspension of fat and protein molecules in water. Googling around, the consensus is that it’s 87% water.  This will vary with whether it’s full-fat or skimmed or whatever, but let’s go with 87%. Egg, meanwhile, is about 75% water.

It gets a little more complicated with butter, as there’s more variation. Most European butters are higher fat content, less water; indeed, EU law says they need to be more than 82% fat, and some are as much as 90%. I’ll admit I don’t buy posh butter, but both the supermarket brands of unsalted butter I have are 83% fat. Factoring in about 1% protein, let’s go with 16% water.

So:
Milk 87% water
Egg 75% water
Butter 16% water

Also, eggs. Eggs have shells. Domestic recipes don’t usually give egg in a weight, just “2 eggs”. But I know the eggs I use contain on average 55g of white and yolk.

Now, I hope I can handle the mathematics, as I’m a little out of practice.

Here’s my Santa Lucia crown ingredients (excluding glaze etc):
250g strong white bread flour
250g plain (all-purpose) flour
125g full-fat milk
125g water
6g active dried yeast
2 eggs, that is 110g egg
3g salt
50g butter, softened
120g caster sugar
A few sprigs of saffron, about 1g

Here’s a table. Column 1 is bakers’ percentage (as it’s half plain, half strong flour, the 100% total flour is divided in two), 2 the above ingredients in grams, 3 is the quantity of water in those ingredients in grams, and 4 is the percentage hydration. I worked out the figures in column 3 by dividing the wet ingredient by 100 then multiplying by the percentage water content discussed above. Eg the milk, 125 (g of milk) ÷ 100 x 87 (percentage of water in milk) = 21.8. Combining the figures in column 4 gives me the total hydration of the dough, ie the total water content of the recipe as a percentage of the flour (100%).

So I now know my Santa Lucia crown recipe is around 65% hydration. Alternatively I can work this out by totalling column 3, dividing this by 500g, the flour weight, and multiplying this by 100, giving 65%, give or take a decimal point. I just wanted to include column 4 so those percentages were writ large. It’s probably overkill… for the two people reading this post. This hydration isn’t that high, so I should be able to mould it better.

Moving on, here’s my brioche recipe.
90g full-fat milk, warmed
25g caster sugar
10g active dried yeast (or 15g fresh)
400g strong white bread flour*
5g fine salt
100g butter, softened
4 medium eggs (220g), beaten

Here’s another table:

So the hydration here – either worked out by adding up the figures in column 4, or by 268.3 ÷ 400 x 100, is 67%, give or take a decimal point again. Surprisingly slightly more than the Santa Lucia recipe. Though they are somewhat different, with the brioche getting more of its liquid content from eggs and having more butter. I find this brioche dough easier to mould but that may well be as it has a higher butter content. I rest it in the fridge until the butter has firmed up more. Perhaps I will tweak my Santa Lucia crown recipe next year, and give it a rest in the fridge to firm up the butter. We can resume this fascinating discussion in a year. Here’s another pic of the Santa Lucia crown, cut open.

* Where you put the apostrophe is debatable. I like to think they’re the percentages of many bakers, not just one, hence bakers’ percentage instead of baker’s percentage. But I don’t suppose it matters much. Anyway, the reason professional bakers use this system is to scale up recipes but I’m not going into that here. The purpose of this post was to get my head around hydration of enriched doughs, and compare two recipes.