The ratios play a very important role in brewing. They settle the proportions between the raw materials and the beer, or between the raw materials and the intermediate products needed for brewing (malt, cooked grains, ...). These grains-to-beer proportions vary according to the type of beer, the original density of the wort and the nature of the raw materials used. Schematically, the brewing ratios are as follows, expressed in volume :
|Volume of raw material
|Volume of wort
|Kind of beer
Industrial brewing is based on the setting, measurement and strict control of highly detailed ratios. This reproducible process approach allows for the brewing of beer ranges with very little fluctuation in sensory properties.
Nowadays, thousands of beer recipes are circulating among amateur brewers. They are based on proportions whose values define a type of beer, in addition to the nature of the ingredients.
What was the state of the brewing art 4 or 5 thousand years ago?
How was a type of beer defined? By its taste, its colour, its strength?
The answer is: by its density, that is the amount of grain used to brew a given volume of beer. The societies of antiquity are neither market economies, nor monetary economies, nor free enterprise economies like those of modern times. The bulk of the population are slaves whose labour feeds the minority of the ruling classes. The dominance relationships are so strong that even the subsistence of the slaves is granted with daily rations of bread and beer.In an economy that ignores money, the value of vital commodities is measured in grains of barley or wheat (Mesopotamia, Egypt), rice (India, China, Japan), or corn (pre-Columbian Andean societies). The social 'value' of a ration of 1 litre of beer is equal to the volume of grain used. One litre of grain/litre of beer = beer of high social 'value'. ½ litre of grain = beer of medium 'value'. ¼ litre of grain = beer for slave ration.
The technique of brewing ratios appeared very early in the history of beer. Mesopotamian, Egyptian, Chinese and Indian brewers mastered this technical approach as early as the beginning of the 3rd millennium BC. Sumerian brewers wrote down the technical details of their brews on clay tablets. The oldest written documents are relatively complex accounts drawn up by brewers, or more exactly by managers of beer-making workshops. They are responsible for the volume of grain or brewing ingredients (malt, beer loaves, baked cakes) they provide to brew the volumes of beer of various qualities they must deliver. Example: with 500 litres of grain, the brewery manager can deliver 100 litres of top beer, 200 litres of standard beer and 200 litres of lower quality beer according to the ratios given above.
This arithmetic seems simplistic. In the practice of ancient brewhouses, the management of beer ratios was more complex. Not all brewing ingredients are equal, even if they are all counted with the same volumetric measure. One litre of barley and one litre of emmer do not provide the same amount of starch. The same is true if you compare raw grains, malt or beer breads.
These specialised managers scrupulously record the volumes of raw grain, loaves, beer bread and malt used to produce a given volume of beer. The raw materials (raw grains) and intermediate products (malt, loaves, beer breads) are perfectly defined and quantified. The quality of the 4 or 5 kinds of beer is specified. The final volume of each is given. These brewery accounts written on clay tablets or papyrus are based on explicit ratios. From one document to the next, the proportions are repeated for the same type of beer.This was the major innovation of this ancient age.
This is the most important innovation in brewing at that time. It shows that four or five millennia ago, brewing techniques were much more advanced than previously thought.
Five thousand years ago, the novelty was no longer the brewing of beer, nor the calculation of the volume of a particular brewing ingredient. What is new is the control of the density of the wort for each brew through ratios. Mesopotamian or Egyptian brewers developed recipes to reproduce, day after day, the same beer qualities (identical wort densities). The study of these ratios and the brewing techniques that accompany them allows us to understand the social logic of this invention.
This technical invention is, as is often the case, the answer to a socio-economic situation: how to produce different kinds of beer for different social categories with regularity?
The social rank of each person should be read in the category of beer he or she drinks. This social quality of the beer is expressed precisely by a ratio between the volume of grains and the volume of beer (namely the wort). At the bottom of the social hierarchy is a ratio of 0.5:1, which reads half as many grains as beer. For a middle social rank, a 1:1 ratio means as many grains as beer. The higher you go up the social hierarchy, the higher the proportion of grains used per volume of beer, 2:1 to sometimes 3:1.
A socio-political use can be inferred. Those with the highest ratios drink the strongest beers. The level of alcoholisation progresses within the social hierarchy in antiquity. In the heyday (palace granaries filled with grain), high ranking members of Mesopotamian, Egyptian, Indian or Chinese societies lived in a state of near-permanent inebriation.
Another use, economic this time, is the system of subsistence in kind of persons subordinate to a temple, a palace or any economic entity. It is based on the distribution of the bare necessities of food, beverage and clothing. Beer was at that time the main beverage given as rations, which were all calculated according to their gross grain equivalent (beer, bread, loaves, coarse flour, ...). The brewer must brew strictly calibrated beers: this set volume of beer = this set volume of grain. These ratio scales are known to all and ascertainable by all, knowing that every stratum of the society is concerned.
These social logics are translated into controlled brewing methods in various cultures. The logic of ratios is general enough to adapt in antiquity to different technical brewing schemes. To date, there are 5 files available to describe and verify the logic of the beer brewing ratios:
- the Mesopotamian records: from the 3rd millennium B.C. onwards, it consists of several chronological sub-folders up to the end of the 2nd millennium.
- the Egyptian records: brewing ratios and mathematical exercises from the Middle Kingdom.
- the Indian records: beer recipes in India from the Maurya empire founded around 322 BC.
- the Chinese records: beer management in Dunhuang between the 7th and 10th centuries AD under the Tang (618-907) and Song (960-1279) dynasties.
- The file of the pre-Columbian Andean societies. In the lack of texts, the highlighting of beer brewing ratios is supported by the analysis of archaeological remains.
These studies show that the technical and social management of beer in ancient times and in various parts of the world was much more advanced than is commonly thought. Beer historians, too often obsessed with its modern, Western industrial history, neglect the records of other continents and ancient civilisations. Deciphering and reading these brewing ratios is not always easy, but the window they open onto the day-to-day social organisation of ancient societies is unprecedented and fascinating.
These large brewing jars have been found by archaeologists: average content 600 litres, pointed bottom jar with a hole, a wide opening. This is the Mesopotamian technique. The Egyptian beer brewing method uses to press various kinds of baked breads with water through a sieve over a tank. The Chinese or Indian brewing methods still proceeds differently. A compact mass of cooked grains is saccharified and fermented using amylolytic ferments. The dilution with water is the last step to control the density of the beer.
Regardless of the method of beer brewing, each method allows for a fairly accurate control of the brewing ratios.