French toast is decided in the soak. Not the pan, not the syrup, not the bread you chose at the shop — the ninety seconds where custard moves into bread and, if you get it wrong, back out again. Everything else in this recipe is recoverable. That isn’t.
The Soak Is The Whole Recipe
Here’s the failure everyone has had. The outside browns beautifully. You cut into it and the middle is dry bread with a wet skin around it, or it’s a swampy grey paste that never set. Both are soak problems, and they’re opposite ones — too little and too much.
A slice of French toast is meant to be a baked custard held inside a bread scaffold. The bread’s job is structure. The custard’s job is to fill the air pockets and then set as the egg proteins coagulate in the pan. For that to happen the custard has to actually get into the crumb, all the way through, and the crumb has to still be strong enough to hold together while it does.
So the real question isn’t “how long do I soak it.” It’s “how much liquid can this slice take before its structure gives out.” That changes with the bread, its age and its thickness — which is why you read the slice rather than the clock.
What Actually Happens Inside The Bread
Bread crumb is a foam — starch and gluten walls around gas pockets. Fresh bread has a lot of free moisture in those walls. That moisture is already occupying the space, so custard has nowhere to go and sits on the surface instead. Then in the pan the free water turns to steam, the surface custard cooks into a skin, and you get the dry-middle version.
Dry the bread out and the walls become thirsty. Now capillary action pulls custard into the crumb quickly and fairly evenly. This is why staleness isn’t a compromise — it’s the mechanism.
The limit is gluten. Soaked gluten softens, and past a certain point the walls collapse under the weight of the liquid. That’s the swampy version. You can literally feel it: a slice at the right point is heavy but holds its shape when you lift it on a fork; one that’s gone too far sags in the middle and starts to tear.
I test with a fingertip on the top face. Press gently. If it springs back at all, there’s dry crumb inside and it needs longer. If it dents and stays dented, it’s saturated. If it dents and slowly rises, that’s the one — pull it now.
Why Stale Bread Isn’t A Compromise
Two days on the counter, uncovered, is my target for brioche. I don’t always plan two days ahead, so the shortcut I use constantly: slices laid out on a wire rack in a 150C oven for 8 to 10 minutes, turned once. Not toasting — no colour at all. You’re just driving moisture off. They should feel light and slightly papery at the edges when you take them out, and they’ll be cool enough to handle in about three minutes.
Cut thickness matters as much as staleness. I cut at about 2.5cm. Thinner than 2cm and there isn’t enough interior for a custard layer, so you’re making eggy toast, which is a fine thing but a different thing. Thicker than 3cm and the outside will be past golden before the centre reaches the roughly 70C that sets the custard.
Custard Ratio: Eggs To Milk, By Weight And By Eye
The ratio I’ve settled on is one large egg to 60ml of dairy. Four eggs, one cup of milk. That’s noticeably eggier than the ratios you’ll see quoted around 100ml per egg, and it’s deliberate — more egg means the custard sets faster and firmer in the pan, which buys you a slightly wider doneness window before the outside burns.
Go too milky and it never fully sets; you’ll cook the slice for six minutes chasing a centre that won’t firm up, and the crust will be bitter by then. Swapping a third of the milk for cream is the best upgrade if you want it richer — fat slows protein coagulation slightly, so a creamier custard forgives a hot pan. It also browns faster, so drop the heat a touch.
Strain the custard. I know it sounds fussy. Whisking never fully breaks down the chalazae — those white cords attached to the yolk — and they show up as pale rubbery specks in the finished slice. Thirty seconds through a sieve removes them permanently.
Ingredients
- 8 slices of brioche or challah, cut 2.5cm thick, dried out as above
- 4 large eggs
- 1 cup (240ml) whole milk, or 160ml milk plus 80ml cream
- 1 tbsp sugar
- 1 tsp vanilla extract
- 1 tsp ground cinnamon
- Pinch of salt
- 2 tbsp butter for the pan, plus more between batches
- 1 tbsp neutral oil
- Maple syrup, powdered sugar and berries, to serve
Instructions
- Whisk the eggs, milk, sugar, vanilla, cinnamon and salt in a wide shallow dish until completely uniform — no streaks of white. Pour it through a sieve into a second dish.
- Heat your oven to 100C with a wire rack inside. This is where finished slices wait, and a rack rather than a plate is what stops the undersides steaming soft.
- Lay two slices in the custard. Give them 30 seconds a side to start, then use the fingertip test: dent and slow rise means ready. Stale brioche usually needs 30 to 45 seconds a side; a thicker or drier slice can want 90.
- Heat a heavy skillet over medium-low. Add 1 tbsp butter and 1 tsp oil together — the oil raises the smoke point so the milk solids in the butter don’t blacken. The butter should foam steadily and go quiet, not brown.
- Lift each slice with a fish slice, let it drip for two seconds, and lay it down away from you. You should hear a low sizzle, not a crack. A loud crack means the pan is too hot; pull it off the heat for 20 seconds.
- Cook 3 minutes on the first side without touching it. Lift a corner: you want an even mid-brown, not a leopard pattern. Flip and give it 2 to 3 minutes more.
- Press the centre of the slice with the back of the fork. Set custard feels springy and pushes back. If it squashes and liquid weeps out, give it another minute per side over lower heat.
- Move to the oven rack and repeat. Wipe the pan with kitchen paper between batches and add fresh butter and oil each time.
- Serve with syrup, a dusting of sugar, and berries if you have them.
Pan Temperature And The Butter Test
Medium-low sounds too cautious and it isn’t. Custard sets around 70C internally. Bread surfaces brown properly from about 150C. The pan has to sit in a range where the outside gets to colour while the middle has four or five minutes to catch up, and that’s lower than most people cook eggs.
My test is the butter itself. Drop it in cold: if it melts and foams within about 15 seconds and the foam holds, the pan’s right. If it foams and collapses to brown flecks in under 10 seconds, it’s too hot. If it just sits there sulking, wait.
The second batch is always faster than the first because the pan has climbed. I turn the heat down one notch before every batch after the first, and I still occasionally forget and get one dark slice. That slice is mine.
Reading A Slice Before You Cut It
Pick it up with tongs and look at the edge. A properly soaked, properly cooked slice shows three visible layers: a thin browned crust, a pale set band about 5mm in, and a slightly darker custardy middle that looks moist but not wet. If the middle looks the same colour as the crumb of plain bread, the custard never got there. Weight tells you too — a finished slice should feel obviously heavier than the bread you started with.
Bread By Bread: What Soaks Well And What Collapses
Brioche and challah are the standards because their enriched crumb has fat and egg already in the walls, which slows collapse. Brioche is the softer of the two and needs a shorter soak; challah is sturdier and I give it an extra 20 seconds a side.
Sourdough works and it’s my favourite in a savoury direction, but its open irregular holes mean custard runs straight through the big pockets and pools. Cut it thicker and expect a less even result. Plain sandwich bread is the one that genuinely disappoints — it’s too soft and too thin, and it goes to paste in seconds. If you’ve got a lot of stale bread and not much patience, bread pudding is the same custard chemistry with none of the timing pressure, because the oven sets everything at once.
If your breakfast plans keep landing on a griddle, the pan-reading habit transfers: the same butter test decides blueberry pancakes, and the batter-rest logic behind buttermilk pancakes is the same idea as staling bread — give the starch time to take up liquid before heat arrives. Belgian waffles are the outlier, since the iron cooks both faces at once and the whole temperature conversation changes.
What I still get wrong: I under-dry the bread when I’m in a hurry, every single time. If you take one habit from this, make it the wire rack in a low oven the moment you decide French toast is happening. Ten minutes there fixes more than any adjustment you can make later.