Room Temperature Sparge Water
Just like most brewers who have been brewing a while, my processes are steeped in brewing dogma. Processes I was told by experts to do. They worked, so I continue to do them. If it works, why not, right?
Then along comes a brewer who tests new processes that fly in the face of the old dogmatic processes and then scientifically proves a lot of these old dogmatic processes as wrong, or not necessary.
One of these processes is sparging. Brewing lore says that in the all grain mashing process, the grains must be rinsed or sparged with hot water in order to help rinse the sugars out of the grain. The temperature of sparge water has been a hotly contested subject for years on the internet. Let’s say most brewers would agree that around 168 degrees is optimum.
Based on this information, I have been sparging my grains with 168 degree water for 5 years without fail, and with great results. So why even explore another way to do it? It works!
I read two articles that suggested a brewer could sparge with room temperature sparge water, let’s say around 70 degrees. The benefit of this would be you don’t have to have another vessel handy to heat up your sparge water, and if you do not have a way to safely transfer hot sparge water to the mash tun, it certainly is a lot safer carrying, lifting, and pouring 70 degree water than 168 degree water. There also is some slight energy savings as you’re not having to heat some of the water twice.
So, with all of these benefits, it would be worth doing, if you still get good results. Logic would dictate that a less than thorough rinse of the grains would reduce efficiency resulting in a lower gravity wort. We obviously would not want that but if we got the same or better efficiency would you switch your sparging process to room temperature sparge?
I decided to put it to the test myself. I was testing our new Robobrew system and when it came to sparging I could have easily heated my sparge water, but then I thought that a lot of brewers might not have all of the equipment and space that I have and room temperature sparge would make it much easier for them. So, I decided to try it and sure enough it worked just fine. All I did was put my room temperature sparge water in a bucket and poured it right in. Super easy. I got 80% efficiency so there was absolutely no negative impact on efficiency or the wort gravity.
Another aspect of sparging with hot water was it would shut off the enzymatic process and lock in your mash profile. Convention says after the mash, you should raise your mash to 168 degrees to stop all enzymatic activity, then sparge with 168 degree water to maintain the 168 degree temperature until the sparge is done. Makes sense.
You would think that if you sparge with room temperature water that it could create some kind of weird enzymatic mess. The two articles I read did blind tastings to compare the same beer sparged with hot water and the one with room temp water and tasters were unable to reliably tell one beer from the other suggesting that room temperature sparge has no negative impact on the finished beer.
I was skeptical, but sometimes it’s fun to try these different experiments for yourself. I would not have believed it if I didn’t try it for myself.