How much water should I put in my mash?

Controlling the wort thickness

The "thickness" of the wort is a ratio of water and malt (grist).

Improving it will bring you the possibility to "manage" the enzymes, responsible for the conversion of starches found in the grain into sugars, which influence fermentability and affect the final flavor of the beer. This conversion is caused by the malt enzymes that act as catalysts.

The challenge of every brewer is to control all the variables that can interfere in the enzymatic action during the mashing, such as:

• Temperature

• Water

• pH

• Enzymes concentration

• Concentration of sugars

• Proteins concentration

With some tools and the right knowledge, these variables are easily controllable.

The main influences are:

The Wort temperature has a lot of influence on the enzyme activation. Temperature is also responsible for the denaturation of enzymes and loss of their catalytic power. The enzymes involved in the mash have different (ideal) temperature ranges to work in optimal condition.

The Wort pH affects enzyme activity. Enzymes need to be in a specific pH range to be and remain active. The ideal pH is usually between 5.2 and 5.4.

Other variables that affect enzyme activity are the concentration of enzymes, sugars and proteins. This balance between these variables is very important, as it influences directly the rate at the starch is broken down into sugars in the wort.

During the enzymatic reactions, the concentration of products such as small carbohydrates chain are concentrated in the wort and decelerating the enzymatic activity what can affect the enzyme stability.

The concentration of enzymes, substrates and products is part of the composition of the wort thickness.

The wort thickness is the ratio of the weight of water to the weight of the malt (grist) present in the wort composition when you start the mashing process.

It is not the final quantity of beer.

Just an example of mash proportion

If we have 15 liters of water for 5 kilos of malt (grist), the proportion will be 3: 1 or 33% malt in relation to water.

Commonly there are 3 ratios (water/malt ):

• Thick mash

• Average mash

• Diluted mash (thin mash).

Thick mash

In a thick wort the concentration of enzymes, substrate and products is high, as there is too much malt for too little water.

We can consider a very thick wort around 2,5 parts of water for 1 part of malt or 2,5: 1 (example; for 5 kg of malt (grist) we start with 12.5 liters of water).

Advantages

Protection against enzymes present in the wort, in other words it is more difficult for them to denature themselves at high temperature.

This feature allows beta-amylase and alpha-amylase to work together, which is very desirable for mash using only 1 temperature. Without the protection of thick wort, beta-amylase soon becomes denatured, resulting in a wort with only products of the action of alpha-amylase. This must has a high concentration of non-fermentable carbohydrates, and the beer has a high final gravity and low alcohol content.

Disadvantages

Difficulty to break the starch, the presence of water is necessary, this is chemically inserted between the glucose molecules during hydrolysis and the lack of water can cause incomplete breakdown of the starch during the mashing process.

Low yield. This type of wort can't dilute all the starch in the solution, which can be very harmful in large-scale production in breweries.

High concentration of products resulting from the breakdown of starch. This feature is easy to check when the initial gravity of the wort is taken. It is generally greater than 1078. These products can interfere with enzyme activity, causing what is called an inhibition generated by starch breakdown products.

In the wort, this inhibition can cause incomplete breakdown of starch and decrease the yield of the mash and harm (spoil) the fermentation.

Some enzymes, especially protease, are very sensitive to the inhibition generated by products and are not very activated in environments with these characteristics. What helps in these cases is to constantly stir the wort, it helps to dissipate the enzymatic products in the wort as they tend to be concentrated close to the enzymes.

Average mash

Wort with a ratio between 2.5: 1 and 4: 1. The proportion that best represents this type of wort is 3.25: 1 (example: 5 kg of malt x 16.25 liters of water).

It retains most of the advantages of very thick wort with a decrease in the negative sides and is easier to handle, which is very important in mashes with various temperatures, wort with this thickness is easier to recirculate.

Although a less thick wort makes the enzymes less concentrated, it makes them more susceptible to denaturation, but denaturation only occurs if there is no adequate temperature control during mashing. Generally, the temperature of the mash between 65 ° C to 68 ° C allows a great activity of beta-amylase before its denaturation.

After denaturing beta-amylase, alpha-amylase remains active because it is less sensitive to high temperature, it remains active up to temperatures of 76 ° C. If mashing with temperature ramps is used, then this denaturation problem does not occur, regardless of the wort thickness.

The average mash also decreases the concentration of substrates and products. This minimizes the effects of the inhibition caused by the excess of products resulting from the starch breakdown, increasing the yield of the mash.

Basically, an average wort has good enzymatic activity, allows easy handling and recirculation using an electric pump, produces a wort with a high fermentability content and a good mashing yield.

Diluted mash

Concentration ratio higher than 4: 1 ratio is considered diluted wort (example: 5 kg of malt x 20 liters of water).

This wort is easy to handle and provides excellent heat transfer rates, it also provides high yield.

The biggest problem is enzymatic stability. Enzymes are less stable in diluted mash and enzymatic denaturation can become a major problem. The greatest attention should be paid to beta-amylase, since it is present in a lower concentration than alpha-amylase. If beta-amylase denatures too quickly, there will be a decrease in the fermentability of the wort. In this case, mash processes are not indicated where boiling water is added to increase the wort temperature.

Conclusion

Each type of equipment, process and recipe requires a different proportion of water and malt. In order to avoid a mistake, the average mash (3.25: 1) ratio would be the best, but be sure to test the others, analyzing what different results you get just by changing the initial amount of water in the wort.

Understanding this concept helps to have greater control over the mashing process, which is very important for making an excellent beer.

Reference: https://byo.com/article/managing-mash-thickness/