No-Sparge Brewing

I am definitely a subscriber to the idea that keeping things simple is a benefit to many things that brewers do in the pursuit of great beer. Simplifying things can have a very positive effect on consistency, ease of brewing, and quality, in addition to generally making the whole process of brewing more enjoyable. Some processes are better candidates for simplification than others. I have never really understood why sparging seems like such a great candidate for simplification because it is already pretty simple.

Sparging is used in brewing for the primary purpose of improving the extraction of wort from malt. Even if malt were free, sparging would still make sense because more beer can be brewed from a given weight of malt, thereby reducing the amount of malt that is required in a batch. This may seem trivial on a homebrewing scale, but using less malt per unit volume means a smaller mash tun is required. If you have a mash mixer and lauter tun, now there are two vessel sizes that are influenced by efficiency. The fact is that malt is not free and sparging is used to reduce malt costs, relative vessel size and the size of malt handling equipment; this is all very relevant to commercial operations.

The no sparge homebrew camp argues that the cost associated with sparge equipment and the hassle of sparging outweighs the loss in efficiency when sparging is omitted from the homebrewing process. I do not entirely disagree with this argument, especially if a brewer has limited space and limited equipment. One of the consequences of not sparging is that the wort gravity of the pre-boil wort is often higher than when the mash is sparged, and the water typically added during the sparge needs to go somewhere.

So, a logical thing to consider is what you have proposed and that is to simply add the mash water volume and the sparge water volume used in a conventional recipe all at the same time to the mash. There are a few problems, however, with doing this.

The first is a practical matter; adding all of the water to the malt requires a larger mash tun than when sparge water is used. For many brewers this really may be a trivial point that has no real bearing on the size of equipment used for the job.

My second point is a bit more real. When mashes become progressively thinner, enzyme stability decreases. Most beer in the world is brewed using a mash thickness somewhere between 2.6 parts water to 1 part malt (weight/weight basis) on the thick end of the spectrum to 4 parts water to 1 part malt on the thin end of the spectrum. Your last brew used 9 gallons (34 L) of water (75 pounds/ 34 kg based on 8.34 pounds/gallon) and 8 pounds (3.6 kg) of malt, or 9.4 parts water to 1 part malt. That is an extremely thin mash and the enzymes in such a mash are much less stable than enzymes in a thicker mash. The rate of the enzymatic reaction is also slower because the concentrations of both enzyme and substrate are reduced as the mash becomes more diluted (for more information on this subject read about Michaelis-Menten kinetics).

This has a direct bearing on your particular problem, and that problem is low wort fermentability. You are successfully extracting wort solids, mainly sugars, from the malt added to the mash, but those wort sugars are not all fermentable, (which they never will be, but in your case this is even more pronounced). The result is a high finish gravity. I suggest using a thicker mash to help stabilize your enzymes. You may also want to use a lower mash temperature. The next time you brew consider using a ratio of water to malt of about 4:1, a mash temperature of 153 °F (67 °C) and a mash time of 60 minutes. Collect your wort using the no-sparge method and then dilute the wort before boiling. Or you can boil the wort immediately after collection and add the water after the boil to adjust the gravity.

The third thing about a very thin mash that may be of concern is the extraction of more tannins than you would get using a thick mash, but I don’t have any references or anecdotal experience to back that up. I put this in as a possibility because many brewers are concerned about tannin extraction and if this were omitted someone would wonder about it.

I do want to touch on something that I see as a bit of a red herring. In your question you indicate that you are considering adding more water in your next batch in order to reduce the final gravity. This method can work, but by adding more water to your batch you will also reduce the original gravity. I think what you really want to do is hit your target original gravity and reduce your final gravity closer to 1.012. The best way to do this is by influencing wort fermentability, and the best way to do that is by adjusting mash temperature and mash thickness. Diluting beer or wort with water to affect the final gravity is nothing more than quite literally watering down the beer, and based on your question I don’t believe that is what you wish to do.

 

Response by Ashton Lewis.