It is hardly necessary to stress the importance of bread as an article of food. It is not only consumed in all countries of the world, but it is also the most acceptable form of food there.
Maurizio in his bock "Grain Foods" refers to bread as the emblem of the highest degree of culture, and gives an interesting account of tbe development of bread from the point of view of cultural history.
Now, wheat which furnishes the material for bread is grown all over the world. Depending on the degree of culture achieved, the form given to the food prepared from wheat also varies greatly. But history demonstrates that in any country which aims at cultural advancement, the final food form arrived at, Is bread. It is in view of the foregoing that an account bas been attempted here of the plan for a cottage scale bakery.
There are many kinds of bread peculiar to the respective countries. For example, there are French, Russian, German. British and other bread, each of which has its own characteristics in materials, methods of making and tastes.
Bread is bound to become more popular throughout the world.
Raw Material For Bread
Wheat Flour
Wheat flour, the main raw material for bread may broadly be classified into high protein(protein over 11% , medium protein flour(protein 8-11%)and low protein flour (protein below 8%).
Flour which contains proteins when moistened and beaten , form gluten, which is elastic and so helps to hold the air and carbon dioxide in the mixture and make it light. In bread making the gluten is developed by kneading to form a strong network which sets on baking. Different wheats have varying amounts of gluten but plain flour on the market can be used for bread making, cakes and biscuits.
Whole meal flour can be used for bread making but cakes and pastery will be
coal-se in texture dark in colour.
Generally speaking, high Protein flour is used as a base with medium and low protein floul mixed in appropriate amounts.
yeast
There are two kinds of yeast…raw and dry yeast. It is convenient to use dry yeast because its handling is simple and its preservation easy.
It is important to remember that:
(a)approximately half as much dried yeast as fresh is required in any recipe.
(b) reconstitution is necessary before using dried yeast. This is done by soaking the yeast in lukewarm water (85℉) containing 1/2 oz sugar to 1/2 pint water the water and sugar used for reconstitution should be substracted from the quantities given in the recipe. Sugar can be omitted, but the proving is more necessary than with fresh yeast.
Yeast is a living plant which requires warmth(80-85"F), food and liquid
so that it can live and reproduce The Ingredients and utensils used in bread making and the atmosphere in which the bread is proved must, therefore, be lukewarm; sudden cooling hingers growth and anything hot will kill yeast before it has had time to multiply.
Other Materials
Carbon dioxide is produced in cookery in the following ways:…
(a) By using bicarbonate of soda with something containing acid, such ascream of tartar, syrup or treacle, or sour milk in for example. ginger
bread and soda cake recipes;
(b) By adding baking powder this consists of an alkali and an acid, and is capable of producing a certain amount of carbon dioxide. This is themost accurate method of raising mixtures. All powders should be kept in airtight jars or tins as they quickly deteriorate if allowed to become damp.
(c) By using yeast which feeds on the sugar in mixtures and produces carbon dioxide. Yeast is used in break making.
As for water, there is no problem generally, if city water is available. However. in the case of drawing water from well, hard water is not desirable.
Water with 5-8 pH is best.
As for the materials for packaging, some countries are using polyethylene.
But many use wax paper or grease proof paper.
Process Description
The plant to manufacture breads involves the following sequence of operation;
l. Air Sifter with Pneumatic Conveyor
Flour should flow into the air sifter to be sifted and to eliminate obstructions and is conveyed to the hopper of the mixer by the pneumatic conveyor.
2. Mixing
Dough is made from flour and such materials as yeast. sugar, salt. jot, yeast food etc. This type of mixer has two steps of speed. low and high. For mass production, a high speed horizontal mixer will be suitable. The dough is fermented in the room for 2 to 4 hrs. and again mixed at this stage.
3. Dough Divider
Mixed dough Is weighed and cut by this machine.
4. Rounder
The weighed and cut dough pieces are carried by the conveyor belt of the dough divider and is rounded with this machine.
5. Proofer Machine
Rounded dough pieces are fermented in this machine under an ideal condition, and these are conveyed by a bucket conveyor to be fermented for about 15 minutes.
6. Moulding Machine
Fermented dough pieces are transferred by shooter and moulded by this machine.
7. Second Fermentation Room
Eased dough pieces on racks are carried into this room which has a temperature of 38-40℃ and humidity of 80-85℃ percent.
8. Oven
Fermented dough pieces are baked by this machine.
9. Cooling Conveyor
Baked products are conveyed by this machine and they are cooled during Conveying.
IO. Slicer & Wrapper
Cooled products are sliced and wrapped automatically.
Manufacturing Characteristics of Bread
Bread is products by making a dough from wheat flour and aerating this with carbon dioxide produced by yeast fermentation. Salt is included in the dough because it regulates the rate of fermentation, toughens the gluten, and prevents the bread from being insipid in taste.
The proportion of water need to make the dough varies with the nature of the flour but usually it is in the region of 15 gallons per 280 lbs. of flour.
The proportion of salt used also varies but it is common practice to use about 5 lbs. per 280 lbs. of flour.
The Proportion of yeast needed depends upon the proposed duration of the Fermentation and can be calculated approximately by dividing 12 by the number of hours that will elapse between the mixing of the dough and the placing of the dough in the oven.
The water need to make the dough is brought to a temperature that will give the finished dough a temperature of 75 to 80"F, the exact temperature required depending upon the proposed length of the fermentation. The necessary water temperature can be arrived at by substracting the temperature of the flour from twice the desired dough temperature.
When bread is to be made by what is known as the straight dough system, the required proportions of flour, yeast, salt, water and any other dough ingredients, such as fat, sugar, bread improvers, are mixed together until a homogeneous dough is obtained and this is then covered over and allowed to ferment in bulk. When about three quarters of the proposed bulk fermentation time has passed the dough is very thoroughly kneaded or 'Knocked back', so as to expel much of the gas and to tighten up the dough. It is then covered once more and allowed to complete its bulk fermentation.
At the completion of the bulk fermentation, the dough is divided into pieces
of the required weight, an operation known as ‘scaling’ and each of these pieces is moulded into a ball. After a short period in which they can recover from the action of the scaling and rounding up, the dough pieces are moulded into the shape required for the type of bread that is to be made.
These finally moulded dough pieces are placed in baking tins and allowed a
fermentation period, which is known as "final proof" so that they can become once more inflated with gas. since much of the old gas had been expelled during the moulding operation. The proving period normally occupies from 25 to 40 minutes. according to the type of bread being made.
At the end of this final proof the tins containing the dough pieces are placed in the oven and baked, The baking temperature is 450 to 500℉, and tbe baking time from 40 to 50 minutes.
面包在食品中的重要地位毋需强调。不仅全世界所有的国家消费面包,而且也是那里最受欢迎的食物形式。莫里齐奥在他的《谷物食品》一书中把面包比作人类高度文明的象征,并且从文明史的角度饶有兴趣地描述里面包的发展过程。
当今世界到处种植作面包原料用的小麦。有小麦制成的食品,它所能具有的形式也因各地文明化程度的不同而有很大差异。但是,历史证明,任何一个旨在文明进步的国家,其最终能达到的食品形式便是面包。
按照上述的观点,我们在这里尝试对作坊规模面包房的制面包方法作一些说明。
不同的国家都有她各自特有的许多种面包。例如,有法国式,俄罗斯式,德国式,英国式以及其他形式的面包,每种面包在原材料、制作方式和口味诸方面都有它本身的特点。
看来,面包终将会在全世界范围内日益流行。
面包的原料
小麦面粉
小麦面粉是制作面包的主要原料,它大体可分为高蛋白质面粉(蛋白质含量超过11%),中量蛋白质面粉(蛋白质含量8~11%)和低蛋白质面粉(蛋白质含量低于8%)。
面粉中含有好几种蛋白质,这些蛋白质经和加水搅打后形成面筋。面筋有单性,从而有助于保持空气和二氧化碳在混合料之中,使混合料变松。在面包制作过程中,面筋靠揉捏作用形成,构成一定强度的网络,它在烘时固定下来。不同小麦的面筋含量不同,而市场上的普通面粉可以用来制作面包、蛋糕和饼干。
全麦面粉可以用来制作面包,但全麦面粉制的蛋糕和糕点质地粗糙颜色暗。
一般来说,高蛋白质面粉用作一种主要成分,并以适当的数量混以中量蛋白质面粉和低蛋白质面粉。
酵母
酵母有两种:鲜酵母和干酵母。使用干酵母比较方便,因为它贮运简便,也容易保藏。 以下两点值得记住:
(a)在任何面包配方中,要求干酵母的用量多到约为鲜酵母的一半。
(b)干酵母在使用前必须复原。做法是:将酵母浸泡于(1/2盎司糖对1/2品脱水的) 温水(85°F);复原用的糖和水,其量应当从配方所给量中扣除.糖可以不加,但对干酵母进行复水活化则比用鲜酵母时更有必要。
酵母是一种植物类生命体,需要温热(80~85°F)、养分和液体才会生存和繁殖。因此,面包制造上所用的配料和器具以及面包发酵所在的周围气体都必须是温热的;在酵母按时完成增殖之前,突然降温会妨碍它生长,任何热的东西又会杀死它。
其他材料
在面包烤房里,二氧化碳的产生有以下几条途径:
(a)碳酸氢钠于某些含酸物质如酒石酸氢钾、糖浆或糖蜜、或譬如象姜汁饼和苏打饼配方中的酸乳等等一起使用。
(b)加入发粉(烘烤粉)。发粉由酸和碱组成,能产生一定量的二氧化碳。这是使混合面料带气鼓起最为准确的方法。各种发粉如果让其吸潮就会迅速变坏,所以都应保存在密封的瓶子或铁罐中。
(c)使用酵母。酵母以混合物中的糖为原料,并产生二氧化碳。面包制作中使用的是酵母。
至于说水,如果有自来水,一般就不成问题。但是,在使用地下井水的场合,若为硬水则不适合。pH5~8的水最适宜。
至于包装材料,有些国家使用聚乙烯膜。但许多国家则使用蜡纸或防油纸。
工艺过程说明
生存面包的设备涉及以下的操作程序:
1.带气力输送系统的风筛机
面粉流送,进入风筛机,以除去有碍的物质,然后由气力输送系统送入混合机进料斗。
2.混合
面团又面粉和酵母、糖、盐、添加剂、酵母养料等物质制成。这种混合机有低、高两档速度。对于大规模生产,宜用高速卧式混合机。面团在室内发酵2~4小时后,仍在台混合机上再次进行混合。
3.面团分切机
将混合好的面团过秤后由本机进行分切.
4.面团搓圆机
过秤和分切之后的面块,有面团分切机的输送带传送,并由本机进行搓圆.
5.面团发酵机
搓圆后的面团在本机内于理想条件下进行发酵,面团由斗式升运机传送,收到约15分钟的发酵作用.
6.面团形成机
发酵过程的面团由滑槽传送,并由本机进行成形.
7.二次发酵室
架子上已膨松的面团被送往本发酵室,此室的温度为38~40℃,湿度为80~85%.
8.面包烤炉
发酵好的面团在此烤炉中进行烘烤.
9.冷却输送机
烘烤后的产品由本机边输送边冷却.
10.切片机和包装机
对冷却后的产品进行自动切片和包装.
面包的生产特点
面包的生产方法是先将小麦面粉制成面团,而后使此面团充以由酵母产生的二氧化碳气体。面团中还掺进了盐,因为盐可以调节发酵速率,韧化面筋,防止面包味道变淡。
制备面团所需的用水比例跟着面粉的性质而不同,但通常范围是每280磅面粉为15加仑.
用盐的配比也有差异,通常做法是每280磅面粉约用5磅盐.
酵母的使用比例取决于设定发酵时间的长短,并且可以粗略地按下法计算:将12除以面团混合到面团入炉两者之间所经过的小时数便得.
制造面团由的水要加热,使最终面团的温度在75~80°F之间,确切的水温要求取决于设定的发酵时间.可将必要的面团温度乘2减去面粉的温度便得这一必要的水温.
当采用所谓直接发酵面团法制作面包时,先将所需比例的面粉、酵母、盐、水和其他面团配料(如脂肪、糖、面包改良剂)一起混合,直至得到均匀一致的面团,然后将它遮盖起来,让它整块发酵.当发酵进行到预定大块发酵时间的3/4时,便对面团进行非常充分地揉捏,即揉紧发面使发过头的回缩,如此驱走大量气体,缩紧面团.然后再次遮盖面团,让其最后完成大块发酵.
大块发酵结束时,将面团分切成重量合乎要求的小面块(此操作称为"面块定量"),然后每一面块都经模制成球形.经过一个很短的时间(在此期间,面团会从定量分切和搓圆的影响之后得到恢复)之后,面块再经模制成合乎待制面包品种所要求的形状.
将最后成形的面块放在听型烤模(烤听)中,让其发酵一段时间,这称为"最后发酵",这样可使面块再次充气鼓起,因为成形操作过程中曾驱走许多以前的气体.此发酵阶段通常需25~40分钟,视待制面包的品种而定.
最后发酵结束时,将装面块的烤听进炉烘烤.烘烤温度为450~500°F,烘烤时间为40~50分钟.