How to stamp sourdough bread with your logo

The cold method, step by step

1. Proof the loaf as usual. Shape it, put it in the basket and let it proof until a floured finger leaves a dent that springs back slowly and not completely, The Perfect Loaf's poke test. An under-proofed loaf springs so hard in the oven that it tears the mark apart; an over-proofed one takes the mark and then slumps.
2. Turn it out and dust the top. Tip the dough onto the peel or the baking paper, brush off loose flour, and sieve a thin, even layer of white rice flour over the top. Rice flour has a higher scorch temperature than wheat flour, so it stays white in the oven instead of browning. That is what makes the mark read.
3. Flour the stamp face and press. Dip the face in the same rice flour, tap off the excess, set it where you want the logo and press straight down, firmly, for a second. Go a few millimetres in, deep enough that the lines still show after the dough relaxes. Lift straight up without twisting.
4. Score away from the mark. Make your expansion cut on the side of the loaf, not through the logo, so the oven spring opens the score rather than the stamp. One long cut at a shallow angle is enough.
5. Bake as usual. The dusted surface stays white; the pressed lines stretch open as the loaf springs and brown darker, so the logo comes out dark on white. Expect the first two loaves to teach you the depth: press a touch deeper if the mark faded, a touch shallower if the top collapsed around it.

You can also press before the proof, straight after shaping. The mark then grows with the dough. Bread Stamps tells customers that a pattern pressed into an 80–100 g roll spreads evenly over the whole bun as it rises, from the 3.5-inch (9 cm) stamp to a roll of about 5 inches (13 cm). That suits rolls and flatbreads; on a big loaf the long proof softens a logo too much, which is why we press after the proof. Bread Experience's sourdough Uzbek stamp bread shows the opposite failure: stamped after the proof, the baker's loaves came out either with a clear imprint and a puffy middle, or with a thin crisp middle and a faded design. The stamp holds only when the dough is not going to rise much more, and the poke test in step one is how you know.

The hot method: branding the crust

The other method heats the stamp and touches it to the baked crust, the way a burger bun is branded. Warm the stamp on the grill plate or with a torch. Branding Irons Unlimited, a US maker, notes that bread, buns and tortillas need a lower temperature than meat, the lowest that still makes a mark in reasonable time. Touch the face to oiled foil so it releases, and press it onto the crust for one to two seconds. Test on the bottom of the first loaf.

Be honest with yourself about when it reads. A burned mark is dark on dark: on a deeply baked country loaf it disappears, while on a pale crust, a soft roll, a bun or a flatbread it looks like a brand. If your crust is the dark, blistered kind, the cold method is the one that shows. The same stamp does both, so you are not choosing at order time.

Which logos survive the oven

A pressed line in dough is not a printed line. It stretches as the loaf grows, shallows as the crumb relaxes, and burns outward when it is branded hot. Fine strokes fade to nothing, small counters, the holes in an 'a', an 'e', an 'o', fill in, and a tagline under the name turns into a row of dots.

• One word, a monogram or a simple symbol. Not the full logo lock-up with the tagline.
• Bold strokes with open space between them. If two lines almost touch on screen, they will touch on the loaf.
• A closed outline, a circle, a shield or a wheat ear, frames the mark and reads from across the counter.
• No fine hatching or gradients. There is no such thing on bread.

We redraw the logo for machining as part of every order, at no cost, and send a digital proof within one business day showing the exact face that will be cut. Nothing is machined until you approve it. That redraw (thickening, opening, simplifying) is where most of the quality of the final mark is decided, and it is the part we would rather do with you than have you discover on the first loaf.

Which size, and why aluminium

A logo on a loaf wants to be read from arm's length, not studied. Medium, marking up to about 75 mm, is the size for a normal 800 g to 1 kg boule or batard; Small, about 50 mm, suits small loaves, rolls, pastries and cookies; Large, 100 mm, only earns its place on very large loaves and flatbreads.

The metal is aluminium, and not by preference: the stamp touches food, and standard machining brass carries lead, so we do not make food stamps from it. Aluminium in the EN 602 food-contact alloys is the recognised choice, and it has two practical advantages on bread. It weighs about a third of the same head in brass, which you notice after the fortieth cold press of a morning, and it heats quickly on the plate when you do want to brand the crust.