In the brewing industry, mashing is a term that indicates the beginning of the brewing process, where crushed grains are mixed with water to create a porridge-like mixture called the “mash.” When this mash is created, malt and other cereal starches in the malt are transformed into sugars, and proteins and other materials are made soluble, thus producing the sweet fermentable liquid called the wort. The mash is a mixture of hot brewing liquor and crushed grain. Your treated brewing water has dissolved minerals in it, with calcium salts (such as calcium chloride or calcium sulfate) being among the essential brewers.
Have you had to deal with a mash that smells bad before, and you are wondering what could have caused it? I have been in that situation before. The reason your mash smells bad is that you used expired yeast, or you didn’t put in the right amount of ingredients you should have used. That bad smell is mostly from pediococcus. It is a bacteria that works aerobically, and it has a vomit kind of smell.
So what happens when your mash is ready? Numerous things occur in your mash while you wait for the process to complete.
Usually, heat is transferred from the hot brewing liquor to the colder crushed grains and the internal part of the mash tun (if it is not preheated). There are easy chemical processes such as the dissolving of starch and the diffusion of water-soluble molecules out of the husk particles. Chemical reactions occur that alter the pH of the mash. Other chemical reactions such as calcium ions reacting with oxalate to form calcium oxalate are happening. Calcium oxalate is a component of beer stone and a standard scale that is found in brewery vessels.
Usually, the high temperature of your mash destroys a lot of the bacterial load of the malt and many malt enzymes with temperature optima that are far below mash temperatures.
I am highlighting all these critical things because all these processes take time and need to be patient. However, some techniques happen so fast. For instance, the stirring process of your mash and the dissolution of water-soluble substances from the grain husks don’t require much time.
Starch conversion is usually the slowest thing that happens in the mash. The moment starch conversion is completed, that is when I am very sure that everything else has been taken care of, so I won’t have to continue mashing to extract the total amount of color, flavor, or aroma from my malts.
While all that is going on in my mash, I will go ahead to get my sparge water ready. I will heat it to go in as soon as my mash has been mashed out and the wort recirculated. The amount of sparge water I use depends mainly on my expected pre-boil wort volume, the amount of first wort in my mash, dead space in my system, and the amount of water I plan to leave behind in my lauter tun.
I don’t usually bother myself to treat my sparge water while I am brewing my liquor. I also don’t use sparge water high in carbonates, nor do I add any acid to my sparge water.
I don’t joke with stirring my mash because it helps to even out the temperature in the mash and mixes the liquids and solids more thoroughly. I stir my mash at least once a day.
Your recipe usually specifies a mash duration. Most homebrew recipes give one hour as a length of time for the mash. But most times, my mash gets converted before 60 minutes elapses.
How do you know if your mash is bad
You will know if your mash is bad if it smells awful like sourdough. Suppose you see something like a film at the top that looks flour-dusted with bubbles. That film at the top means it has been infected. It would be best if you did not consume a mash that has gone bad. It would be best if you got rid of it. I have had to deal with a mash of mine that got bad. It was so painful. I tried to salvage the whole thing, but it ended up becoming worse, so I had no other option than to discard it.
What should mash smell like?
I know this may seem weird to you, but I love the natural smell of my mash. Mash should have a solid and sharp yeasty smell. If your mash smell like puke or rotten eggs, then there should be a problem you should address.
Should you stir mash while fermenting?
I stir my mash while it is fermenting because stirring helps to even out the temperature in a mash, and it also helps to mix the liquids and solids more thoroughly. I always make sure I stir my mash twice a day. If you are a homebrewer, stirring your mash has to do with opening up the mash tun and exposing the mash to cooler environmental temperatures. Also, you will need to add heat, or a small amount of boiling water, to bring the mash temperature back up to your target. If you cannot heat your mash tun directly and don’t have space for a boiling water addition, you will not be able to stir the mash without losing heat. And it would be best if you did not forget that you can mash in your kettle and transfer it to your lauter tun later.
Why does my mash taste sour?
The reason your mash taste sour could be because of the sour lactic acid in it. It usually happens if you leave your mash for a few days at 110 to 120 degrees Fahrenheit. There will often be a layer of nasty-smelling malt on the top that can be scooped out. The mash beneath it is usually soured.
Some people love to drink sour beer, and it is not weird to consume that. I crave that, too, sometimes.
So, if you also want to brew sour beer, there are several methods you can employ to create that. You can either add lactic acid to your brewing water or include acidulated malt in your grain bill. Both ways will lower the pH levels of both the mash and final wort, thus, giving a tart, sour edge to the last beer depending on how much is added.
Some advanced techniques involve adding either cultured lactic acid bacteria or Brettanomyces, a mixed lambic culture of Brettanomyces, Pediococcus, and Lactobacillus, or making the beer with unsanitized oak ingredients while the beer is still in the secondary stages of fermentation. This will give you a sour mash after the process is completed.
Conclusion
Your mash smells bad most times because there is a problem with the fermentation process. It is always good you dispose of any mash that has been infected.
I don’t neglect to stir my mash when I am brewing; it is an integral part of the process you should also take seriously.