The Mash - part two
Following an hour-long steep and subsequent vorlauf, we begin to transfer our now hot sugary liquid (wort) from the mash tun over to the kettle.
This takes between an hour and three hours. The length of time is dependent on the batch size as well as the amount and variety of grain used. Transferring too fast risks a stuck mash, in which the space below the false bottom is transferred off faster than liquid can make it through. Suction then occurs and the grain bed is essentially stuck to the bottom stopping further liquid through. Although it can be remedied it is far from ideal. Slow and steady is often the best means to avoid issues down the line.
For further detail on how to avoid a stuck mash a great starting point can be found here: https://www.homebrewersassociation.org/how-to-brew/5-tips-for-avoiding-a-stuck-sparge/
We start to Sparge as transfer begins. This involves a continuous flow of water (77 Celsius) into the mash tun over the grain bed. A slow and steady stream ensures an equal distribution and that the grain bed isn’t disrupted. The aim here is to extract as much of the fermentable sugars as possible. Getting to the batch size we need, to our target gravity and bang for buck extacting all the grain has to offer. The rate of flow of sparge water matches that of the flow of wort out to the kettle.
Throughout the transfer we check the gravity. This measures the relative density of the liquid and directly relates to the potential alcohol content. The higher the density the more sugar. For ease at this stage we use a hydrometer and chill samples to 20 Celsius for reliable measurement. The first liquid drawn is the highest sugar content and this gradually reduces as the sparge water makes it’s way through the mash tun. As we check at specific intervals of the transfer we are able to gauge the efficiency of the mash and whether this is on target for the recipe. Too high and we may need to sparge longer or liquor back in the boil. Too low initially would mean less sparging and a lower final batch volume. These decisions are directed by the hydrometer readings. The more you get to know your systems efficiency the easier this becomes.
Our next post will look at the boil
This post follows on from The Mash - part one which can be found here: https://www.wasteddegrees.com/post/the-mash-part-one