Details Of Mashing

We all know that the process of brewing beer involves saccharification, but do you know why it is done and what happens to our wort during saccharification?
Saccharification is the breakdown of insoluble macromolecules (starch, protein, hemicellulose, vegetable salts, etc.) in the malt into soluble low molecular substances (such as sugars, dextrins, amino acids, peptides, etc.) using various hydrolytic enzymes contained in the malt itself, as well as water and hot water. The various dry substances dissolved in water are called "leachates" and the resulting clarified solution is called wort or wort. The ratio of the leachate content of the wort to all the dry matter in the raw material is called the "anhydrous leaching rate".
The purpose of saccharification is clear: we need a liquid wort that is rich in nutrients, breaking down the components of the solid malt into small molecules that enter the water to form a liquid that is suitable for yeast growth and easy to drink. The purpose is to break down and extract the raw material so that more of the soluble material is dissolved and the insoluble material is converted into small soluble molecules by the action of enzymes, resulting in a wort containing a certain amount of fermentable sugar, yeast nutrients and beer flavour.
What exactly happens during the saccharification process? During saccharification the anhydrous leachate of the raw malt increases from around 17% to 75%-80%. The material changes that occur include the breakdown of starch, protein, beta glucan, lipids, phosphates and acid formation.
1、Decomposition of starch
The presence of starch in the finished wort must not be allowed. Its presence is not beneficial to the beer and tends to cause starch turbidity in the beer, and also reduces the leaching rate of the raw material. This is why starch must be broken down to the point where it does not react colourfully with iodine (in practice, iodine can be used to identify whether the breakdown of starch is complete, iodine will appear blue to red when it encounters starch, but will not change colour when it encounters small sugars). Alpha amylase is more stable to heat and acts quickly, producing maltose, glucose and small molecule dextrins when acting on straight-chain starch; when acting on branched-chain starch it produces bounded dextrins, maltose, glucose and isomaltose, with the optimum temperature for alpha amylase being 72°C-75°C and the inactivation temperature being 80°C. Beta amylase, on the other hand, is less heat resistant and slower to act on starch, producing a large amount of maltose and a small amount of dextrin, with the best temperature for beta amylase being 60°C-65°C, with rapid inactivation at 70°C. I believe that if you want to produce a dry beer you can try to keep the saccharification temperature and time in the optimum period for beta amylase to produce more fermentable sugars, whereas if you want to produce a fuller beer you can increase the temperature to the optimum period for alpha amylase to obtain the required dextrins and unfermentable sugars. Of course it is not only the temperature that has to be varied but also the breakdown time of both enzymes and when and at what temperature they lose their activity.
2. Protein breakdown
The solubilisation of proteins already takes place during the preparation of the raw material. However, the hydrolysis of proteins during saccharification is still important, as it is directly related to whether your beer has an excellent brewing hold and whether it provides the yeast with a sufficient source of nitrogen, and the breakdown of proteins is extremely prone to errors. Too long a protein rest will result in a beer with very poor foaminess. As its main role is played by endopeptidase and carboxypeptidase, their optimum temperatures are at 40°C-65°C and 40°C-60°C, while at 50°C-55°C protein decomposition is strongest, so the protein rest temperature is generally controlled at 50°C-55°C. The inactivation temperature of protease is 80°C and the optimum pH is 5.0-5.2. We can adjust the protein resting temperature and resting time and pH to regulate the protein content and type in the wort. The resting of the proteins must match the dissolution state of the malt.
3. Decomposition of beta glucan
The β glucan in malt is the supporting skeletal material between the endosperm cell wall and the endosperm cells. The large molecules of β glucan are insoluble, the small molecules are soluble. The dissolution of the large glucan substances in the malt at around 35°C increases the mash viscosity (this is why the wort we prepare at the beginning is slimy and sticks to the floor and is very difficult to clean after a while) especially in poorly dissolved malt, where the residues of beta glucan are high and the mash is difficult to filter. This is particularly a problem in the production of wheat beers, where the leaching of β glucan is often difficult if no measures are taken. Therefore we need to degrade the β glucan effectively so that the β glucan degrades into dextrin and low molecular glucan, the mash is rested at a temperature of 37°C-45°C (low temperature feeding) and the PH is below 5.6, which will facilitate the decomposition of the β glucan. Also in the crushing of the malt care should be taken to crush it evenly otherwise it will also indirectly lead to an increase in β glucan. In practice, malt with good solubility should be selected and the malt crushed and rested at a low temperature.
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