German Vollkornbrot: Dense, Dark, and Sliceable

Whole rye flour has plenty of protein, and almost none of it will link up into gluten. What holds a Vollkornbrot together is a group of water binding sugars called pentosans, which take up several times their own weight in water and set into a gel in the oven. That single fact drives every number below: 80 percent hydration, a batter you stir rather than knead, a loaf pan instead of a banneton, 70 to 80 minutes in the oven, and a 24 hour wait before the first slice.

Why rye behaves nothing like wheat

Wheat dough gets its structure from a gluten network you build by folding and stretching. Rye has the proteins but they will not form that network, so folding a rye dough does nothing except tire your arm. Structure comes instead from the pentosans in the bran and endosperm, which is why a rye dough at 80 percent hydration feels like thick plaster while a wheat dough at the same figure would be soup.

The second difference is enzymatic. Rye is rich in amylase, which converts starch to sugar. In a hot oven that conversion runs fast enough to break the starch gel down before it sets, and the result is the sticky, sunken crumb every rye baker meets once. Acid slows amylase down, and producing that acid is the real job of the rye sour.

The grain bill: 600 g, all of it whole

Total dough is 1,092 g, which goes into a single pan and bakes down to about 940 g (2 lb 1 oz). The 25 percent whole wheat is there for a little structure and lift. Drop it and you get a denser, flatter loaf that is still perfectly good, but the slices get harder to cut cleanly.

The rye sour, and why a quarter of the grain is prefermented

• 20 g ripe rye starter
• 140 g whole rye flour
• 140 g water at 90°F (32°C)

That is 300 g of sour carrying 150 g of flour and 150 g of water, which is 25 percent of the 600 g grain bill prefermented. Leave it 14 to 16 hours at 78°F (25.5°C). It should roughly double, then settle back a little, and smell sharply acidic rather than sweet.

A ripe rye sour typically lands somewhere around pH 4.3 to 4.6, and that acidity is what keeps amylase in check during the bake. Cut the sour to 10 percent of the grain and the loaf will look fine going in and come out with a gummy band above the base. If you feed a wheat starter and have no rye culture, convert a spoonful over two feeds with whole rye flour: the rye and wheat starter comparison covers the differences.

The soaker, and what cracked rye is doing

Put 100 g of cracked rye, sometimes sold as rye chops or coarse rye meal, into a heatproof bowl and pour 130 g of boiling water over it. Pour away from you and set the bowl on a stable surface first. Cover and leave 8 to 12 hours at 72°F (22°C).

The soaker takes up all 130 g and swells to 230 g. Skipping it is tempting and costly: dry cracked grain added straight to the dough will pull water out of the crumb during the bake and leave hard, gritty specks. If you only have whole rye berries, simmer 100 g in 300 g of water for 35 minutes, drain, and use 230 g of the drained grain so the water balance stays intact.

Getting to 82°F with a five factor sum

Rye wants a warmer dough than wheat. Target 82°F (27.8°C). Because this dough has two preferments, use a five factor sum: multiply the target by five, then subtract the flour, room, sour and soaker temperatures plus a friction factor of 2.

Five times 82 is 410. Flour at 68°F, room at 70°F, sour at 78°F, soaker at 72°F and friction of 2 add up to 290. That leaves 120°F (49°C) for the mixing water. In metric: flour 20°C, room 21°C, sour 25.5°C, soaker 22°C, water 49°C. Stay under 125°F (52°C) whatever your sum says, because above that you start killing the culture you spent 16 hours building.

Mixing a dough that never becomes dough

Combine all of it at once. There is no autolyse, no folding and no windowpane to chase.

• 200 g whole rye flour
• 150 g whole wheat flour
• 200 g water
• 12 g fine sea salt
• 300 g rye sour
• 230 g soaker

Work it with a stiff spatula or a dough hook on low for 4 to 6 minutes, using water at the temperature the sum above gave you, until the colour is uniform and no dry flour remains. The texture should be somewhere between thick porridge and modelling clay. It will not clean the sides of the bowl and it will stick to everything, which is correct. A wet spatula and a bowl of water beside you does more good here than flour on your hands.

Into the pan: choosing it and filling it

Use a 23 by 13 cm (9 by 5 inch) loaf pan, which holds about 1.9 litres (8 cups). Grease it well and line the base with parchment. Rye sticks harder than any wheat dough you have handled.

Scrape all 1,092 g in, then wet your hand or the back of a spoon and press the surface level, pushing the dough right into the corners. The pan will be a little over half full. Smooth the top properly: whatever texture you leave is the texture that bakes, because this dough does not relax into a level surface on its own.

Proofing: what to watch instead of a doubling

Cover and proof 2 to 3 hours at 82°F (27.8°C). You are not waiting for a doubling and you will never get one. Three signs tell you it is ready:

1. The dough has climbed 1 to 1.5 cm (0.4 to 0.6 inch) up the pan.
2. The rye flour dusting has opened into fine cracks across the whole surface, not just at the edges.
3. A wet fingertip pressed lightly into a corner leaves a dent that stays.

Overproofing shows as cracks that have widened into gaps and a surface that has started to dip in the middle. At that point bake it immediately: waiting longer only deepens the collapse.

Fifteen minutes hot, then an hour low

Preheat to 480°F (249°C) with a steam tray on the oven floor, 30 minutes at least.

1. Load the pan and pour 100 g of boiling water into the steam tray. Bake 15 minutes at 480°F (249°C).
2. Pull the steam tray out using a dry towel, since a tray that has just flashed 100 g of water will scald straight through a damp one, and drop the dial to 375°F (191°C).
3. Bake a further 55 to 65 minutes.

Total is 70 to 80 minutes, which is roughly the same oven time a 2 kg wheat loaf needs even though this one weighs half as much. The dense, wet crumb conducts heat slowly, and the long low stage is what dries the centre without burning the crust.

Reading 208°F, and getting the loaf out of the pan

The loaf is done at 208°F (98°C) in the centre. Push the probe in through the top at an angle so the hole closes as the crumb settles. Colour will not tell you anything useful here, because the rye dusting darkens long before the middle is set.

Let it stand in the pan for 10 minutes, then take the pan with dry mitts, run a thin knife around the edge and turn it out onto a rack. Turning it out immediately risks tearing the still soft base; leaving it in for half an hour steams the crust soft from below.

The twenty four hour rest is not optional

Cool completely on the rack, about 3 hours, then wrap the loaf in a linen or cotton cloth and leave it on the counter for a further 24 hours before cutting. Total from oven to first slice is 27 hours.

This is where most first attempts are lost. The starch gel that gives rye its sliceable crumb goes on firming for the best part of a day after the bake. Cut at 3 hours and you get a crumb that smears on the knife and reads as underbaked, which sends people back to add oven time they did not need. The same loaf cut the next morning slices clean. If your wheat loaves have the same problem for different reasons, the gummy crumb walkthrough separates the causes.

Slicing, and what the crumb should look like

Use a long serrated knife and cut 5 to 8 mm (0.2 to 0.3 inch) slices with a sawing motion and almost no downward pressure. A 940 g loaf gives you roughly 35 slices at 6 mm, about 26 g each.

The crumb should be even, close, and slightly moist to the touch, with the softened cracked rye visible as darker flecks. Holes larger than about 5 mm (0.2 inch) mean the sour was over active or the proof ran long. A dense, wet band along the base means the sour was too young or the bake stopped too early.

Keeping it for ten days

Wrapped in the same cloth, cut face down on a board, this loaf keeps 7 to 10 days on the counter. Acidity does most of that work, which is exactly why the style exists.

Do not refrigerate it. Between about 39°F (4°C) and 50°F (10°C) starch firms up fastest, so a fridge stales bread quicker than a counter does. For longer storage, slice the whole loaf first and freeze it in portions of 6 to 8 slices, which toast straight from frozen in 3 to 4 minutes.

The three faults that make a rye loaf gummy

Almost every failed Vollkornbrot comes down to one of three things, in this order of likelihood. The sour was too young or too small, so there was not enough acid to hold amylase back during the bake. The low stage of the bake was cut short, so the centre never reached 208°F (98°C). Or the loaf was cut before the 24 hours were up, in which case nothing was actually wrong with it. Check them in that order before you change the formula, because the formula is rarely the problem.

The rye loaf in grams and hours

All of it in one place, same numbers as above.

Rye sour, 14 to 16 hours ahead at 78°F (25.5°C), 300 g total: 20 g ripe rye starter, 140 g whole rye flour, 140 g water at 90°F (32°C).

Soaker, 8 to 12 hours ahead at 72°F (22°C), 230 g total: 100 g cracked rye, 130 g boiling water.

Final dough, 1,092 g total: 200 g whole rye flour, 150 g whole wheat flour, 200 g water at about 120°F (49°C), 12 g fine sea salt, 300 g rye sour, 230 g soaker.

Overall totals: 600 g grain (350 g whole rye flour, 150 g whole wheat flour, 100 g cracked rye), 480 g water at 80 percent, 12 g salt at 2 percent, 25 percent of the grain prefermented.

Method: mix 4 to 6 minutes to a dough temperature of 82°F (27.8°C), scrape into a greased 23 by 13 cm (9 by 5 inch) pan, smooth, dust with rye flour, proof 2 to 3 hours at 82°F (27.8°C) until the dough has risen 1 to 1.5 cm (0.4 to 0.6 inch) and the dusting has cracked.

Bake: 15 minutes at 480°F (249°C) with 100 g of steam water, then 55 to 65 minutes at 375°F (191°C), out at 208°F (98°C) core. Rest 10 minutes in the pan, cool 3 hours, wrap in cloth, wait 24 hours, then slice at 5 to 8 mm (0.2 to 0.3 inch). Finished weight about 940 g (2 lb 1 oz).