Can you brew with distilled water?

I noticed that I was getting several hits to this blog from people google searching about brewing with distilled water. Let it never be said I don’t give the reader what they want!

So, can you brew beer with distilled water?

Short answer: Yes!

Longer answer: Yes! In fact, sometimes you HAVE to.

There’s a persistent myth in homebrewing circles that brewing with distilled water can lead to serious problems, and that is simply not the case. Let’s look at the myths and bust them.

Myth: Yeast need minerals that are missing from distilled water

This one is based on semi-factual information. If you were trying to feed your yeast on straight, pure, refined sugar in distilled water, you’d run into nutrient problems. However, raw material from unprocessed living things contains tons of minerals, amino acids and vitamins. Because you’re using malted grains, your mash contains all the good stuff inside the plant cells, even if you’re brewing with malt extract. The fact is, with all the vitamins and minerals inherently found in the grain, your yeast is going to run out of food to eat long before it runs short of minerals.

Myth: You can’t use distilled water because the yeast cells will pop from osmotic pressure.

No way! You’re not adding the yeast until after you’ve made the wort. In other words, there’s a TON of stuff dissolved in the water when the yeast sees it. The osmotic pressure would draw water OUT of the cell, not push it in to pop it.

Furthermore, yeast is totally stable under distilled water anyway! In the absence of cryorefrigeration, yeast is commonly stored under distilled water. It’s not ideal, but it works. (Stored in distilled water at room temperature, yeast is stable in storage for a year. Cryo-stored yeast is stable indefinitely. It has been successfully revived after 60 years, and there’s reason to believe it is stable much longer than that.)

Myth: You can’t use distilled water because the pH is wrong.

First off, who cares? Having a less-than-ideal pH can give you efficiency issues, which you might care about if you were brewing hundreds of barrels. For a homebrewer, it’s easier and cheaper to deal with poor efficiency by adding an extra pound of grain. If you’re extract brewing, it’s totally irrelevant.

Second, distilled water is likely to have a pH closer to ideal than hard water, anyway.

Myth: Distilled water doesn’t have enough calcium to convert the starch in an all-grain mash.

Many resources say that 50 ppm calcium is the minimum for making beer. This is so much baloney. The water in Plzen, in the Czech Republic, is 10 ppm Calcium, and they invented one of the most popular modern lagers. Plzen brewers have been using water that is well below “minimum” to make beer for over 1000 years.

Low calcium levels will reduce the efficiency of your starch conversion. This is not a concern for extract brewers, and all-grain brewers can work around it by adding more grain. If you’re really worried about it, add 1 gram of gypsum to 5 gallons of distilled water to bring it up to authentically Czech levels of calcium content.

Myth: Commercial brewers don’t use distilled water

Nope. I have a friend who is a professional brewer (at a brewery that will remain nameless because I don’t know if they want their trade secrets out there.) They brew a pilsner with distilled water because the water used in traditional pilsners is very soft. You can’t make an authentic pilsner with hard water. Their fermentations go just fine, and the beer is delicious.

Fact: Distilled water will not give you the correct taste for some beer styles

Ok, this one is very true. Some beer styles are brewed with hard water because that is what is available in the areas where those styles are traditionally made. Stouts are one noteworthy example. Brewed traditionally in northwestern England and Ireland, where the water is naturally very hard, a distilled water stout may not have the taste you’re looking for. Or you may love it.

So what water should I brew with?

If you want to keep it simple, brew your beer with water that tastes good. My tap water is not great, but when I run it through a filter, it’s fantastic. So, most of my beers are brewed with filtered tap water. My tap water is also very hard, so sometimes I want softer water for a particular style. I use distilled water in those cases, and I have never run into any problems.

If you want to get more specific about your brewing water, stay tuned. I have a post planned for the near future about building the perfect water for your beer.

Acknowledgement

I’d like to give a big thanks to my father, who is a yeast biologist. He’s taught me a lot about growing, feeding, and caring for yeast, and I couldn’t have written this post without all those helpful chats.