Rye bread is a regular bread type. It is baked of dough from broken or grinded rye. It used to be eaten as daily bread, but wheaten bread is eaten more these days, because of the light structure. Rye bread contains a lot of fibres and iron.
Rye bread can be divided into two types:
- Frisian rye: made of broken rye, no yeast is used, sweetish taste
- Brabantine rye: made of grinded rye, yeast or leaven is used, sourish taste.
The Frisian- and Brabantine rye are as ingredients and process so different that they are almost incomparable. Both production processes will be described.
Production process Frisian rye bread
Frisian rye bread is a very dark product with visible rye grains. The product has little cohesion.
The recipe which is used for Frisian rye bread is: 100 kg broken rye, 70 kg water, 1kg salt, 0.35 kg lactic acid and 15-25 kg old rye bread. Malt, syrup, preservative or flour are sometimes added.
- In most bread types meal or flour is used. A fine grinded form of wheat or rye. In Frisian rye bread are broken rye grains used. These grains have a section of approximately 1 mm. The starch and protein are still in the grain. This means that the grains can not built a structure with the other grains.
- The large amount of water is needed for the liquid absorption of the rye grains.
- Salt is used as a taste intensifier.
- Lactic acid is used to give the bread the fresh, sourish taste.
- Old rye bread is the finished product from a previous charge. Because this bread is already baked. The starch from the grains is already stiffened. It is therefore cooked or soaked before it is added. This gives the dough a certain cohesion. The old rye bread should be spread fine (grinded). In addition should it not be too dark, for this would give dark dots in the end product.
- Malt or syrup gives a sweeter taste and darker colour to the end product.
- Preservative gives a longer tenability to the product. It slows down the growth of moulds and ferment.
- Flour gives the bread more cohesion. The starch from flour is fairly accessible and stiffens through that easily. A moderate flour type is usually used, so no rye meal. A moderate flour type gives a better cohesion.
All ingredients are mixed. The water is very hot (almost boiling) while added. The grains absorb the water faster because of the high temperature. After the mixing the dough has no cohesion yet.
The dough is left to rest for 1 up to 2 hours. The dough temperature is now 50ºC. The rest time gives the grains more time to expand. The dough stiffens because of this and is easier to process.
A zoetpanne is sometimes used. This is a mixture of broken rye grains and water. This is placed in an oven for one night (at 60ºC). During this rest, the enzymes (amylasen) break down a part of the starch to dextrins and sugars. The dextrins stick and provide the cohesion in the bread and make it a tender product as well. The sugars give the bread a sweeter taste.
Shaping and rolling
The doughpieces are shaped. They are then rolled through (burned) brans and placed in closed trays. These closed trays prevend flowing out of the dough.
The bake time of the rye bread depends on the desired colour and taste. The bake time is between 8 and 24 hours at 110ºC. The bread is warmed up quickly by spraying steam in the oven at the beginning of the baking process. The steam condenses on the cold dough and increases the heat transfer. In addition postpones the condensed steam crust forming and brown colouring, because it keeps the crust a bit longer ‘wet’. Otherwise the outside of the bread would be coloured too much because of the long bake time. Burning of the crust would be possible too. The long bake time is needed for the inner part of the dough to get the heat treatment as well. The heat transfer is slow because the dough is so compact and contains no air bubbles. The dextrinating of the starch continious during the baking. This gives the sweeter taste to the bread. The bread gets a dark brown colour because of the Maillard reactions (reactions between proteins and reducing sugars). The temperature during the baking process is low (110ºC). This prevents the bread from colouring too heavily and burning.
The rye bread can be cooled after the baking. Also cooling takes a long time because of the low heat transfer. Cooling tunnels are used to speed up the cooling process which also reduces the chance of contamination.
The Frisian rye bread is generally sold as a sliced bread. The slices are just a few millimetres thick. The chance of contamination during the cutting is big.
The rye bread is packed in plastic cups with foil or in cling film. The bread often contains preservatives, but is not tenable enough yet.
After the packing, the rye bread is pasteurized to cut off contamination. The bread is pasteurized for 15 minutes at 80ºC to guarantee a tenability of several weeks up to a few months. This time and temperature is for the inner part of the rye bread, the actual heating takes a lot longer.
Production process Brabantine rye bread
The Brabantine rye bread can be divided into sweet and sour rye bread. At the rise of sweet rye bread, yeast is used. Leaven is used for the sour rye bread. More information is given at ‘ingredients’. The production process of both types are almost the same and comparable with the production process of wheaten bread. Brabantine rye bread is a product with a build up gluten network. The colour is much lighter than the colour of Frisian rye bread.
The basic recipes of the two types of Brabantine rye bread are:
- Sweet rye bread: 100 kg rye meal, 1 kg yeast, 1kg salt and 50 kg water.
- Sour rye bread: 100 kg rye meal, 2.2 kg leaven ( from 10 kg rye meal, 10 kg water and 0.200 kg yeast), 2 kg salt and 47 kg water.
Wheat meal and/or preservative is often added.
The functions of the basic ingredients are mentioned in the art of Frisian rye bread. The wheat meal gives a better gluten network, for rye itself contains just a small amount of gluten protein. A brew is often used with the use of a preservative because the preservative restrains the work of yeast. A brew is a mixture of 20 kg rye, 20 kg water and de entire amount of yeast. The brew is kept at 32ºC for 30 minutes. This activates the yeast and the preservative will then restrain the yeast less.
Leaven is only used in sour rye bread. It is a dough from 10 kg rye meal, 10 kg water and 0.200 kg yeast. This mixture is prepared 20 hours before the production of the rye bread and put away on a warm place (>30ºC). Yeast multiplication, lactic acid bacteria growth and lactic acid production (by lactic acid bacteria) take place during the resting phase of this dough. Because the production of leaven takes a lot of time and the quality can differ a lot, also pure cultures are used often now a days. These are lactic acid bacteria cultures that are ready for use.The taste of this is more constant and it saves a lot of time. Yeast is then also added to the dough.
All the ingredients except the preservative are mixed and kneaded. The kneading time depends on the type of kneader. The kneading takes only a few minutes with a intensive high-speed kneader. But with a conventional kneader, the kneading can take 45 minutes. During the kneading, the proteins unwind themselves and form bonds with one another. This forms the gluten network.
When the gluten network has developed sufficiently, the dough can be divided in dough pieces. Every piece forms a rye bread eventually.
Shaping the dough pieces makes all the dough pieces of equal lenght and nicely rolled up. The dough pieces can then be placed in a greased baking tin.
To help the yeast with the CO2 (carbondioxide) production, the dough pieces are placed in a rising case. The circumstances are favourable for the carbondioxide production and the bread does not form a crust, because of the high humidity. If the bread would get a crust as effect of dehydration, this crust would tear during the rising. The rising takes 1-1.5 hours at a relative humidity of 85% and a temperature of 35ºC.
The process of shaping and rising can possibly be repeated. In that case the structure will become finer. The formed, large gas bubbles are split in multiple, smaller gas bubbles during the shaping. The small gas bubbles will grow and become large bubbles again during the rising.
The dough pieces are now ready to be baked. At the beginning of the baking process, steam is injected into the oven. This steam condenses upon the bread. This prevents the immediate forming of a crust and also improves the heat transfer. The crust should not immediately be formed, because the bread is still rising and otherwise would tear the crust up during this volume increase of the bread. The baking process takes 2-4 hours at a temperature of 200-220ºC. This baking temperature is considerable shorter than the baking time of the Frisian rye bread. Brabantine rye bread contains a relative large amount of gas bubbles, which speeds up the heat transport.
The rye bread is cooled after the baking. The cooling of the Brabantine rye bread takes less time than the cooling of the Frisian rye bread. But to speed up the cooling process, also for this bread the cooling tunnels can be used.
Also the Brabantine rye bread is generally sold a slices bread. The slices are only a few millimetres thick. During the cutting the chance of contamination is big.
The rye bread is packed in plastic cups with foil or in cling film. Brabantine rye bread does not always contain preservative. The tenability is therefore lower than the tenability of Frisian rye bread, several weeks.
After the packing, the rye bread is pasteurized to cut off contamination. The bread is pasteurized for 15 minutes at 80ºC to guarantee a tenability of several weeks. This time and temperature is for the inner part of the rye bread, the actual heating takes a lot longer.