Dear Mr. Wizard,

In the January-February 2002 issue, there was a question from John “Mick” Barns concerning mashing efficiency and undershooting the target gravity given in the recipe. I have also experienced this same problem and have adjusted the specific gravity using the ProMash software. I am now ending up close to the OG I want by adjusting the amount of base malt in my recipes. The question I have is, should I also increase the amounts of crystal and other non-base malts? It seems that I am getting the colors and flavors I desire from the crystal and dextrin malts, but I would like some advice.

James Stewart
Riverside, California

Mr. Wizard replies:

This is one of those questions that raise issues extending much further than simply hitting the target original gravity. In your case, you like the color and flavor intensity of the special malts, but you have had problems hitting the target gravity. Increasing the weight of the base malt is certainly the most direct way to deal with the issue and is the method that most commercial brewers use to hit their specified original gravity. If you are not too far off target, then this is the way to go.

Base malts are used for a number of reasons, yet the most important feature of base malts is their contribution to fermentable extract. If wort did not contain fermentable extract, there would be no beer. For this reason, one could argue that base malt is the single most important ingredient in beer. The point here is that, if you need more extract, adding more base malt is the most logical response. In doing so, however, questions arise about the similarity of the wort produced and the wort described by the recipe.

I have always figured that if I am not getting what I want from the base malt, I may be missing something from the specialty malts as well. Base malts change because of seasonal fluctuations in the barley crop and in the specifications used amongst maltsters. If the malt used has a lower laboratory yield than the base malt originally used in the recipe, then the weight of base malt should be increased to adjust for the difference. On the other hand, if the lab yields are the same, but the wort gravities are not, the difference most likely has to do with something in the brewing process. That could be milling, mashing, lautering or a combination of these steps. If this is the case, then it’s likely that the special malt color and flavor intensity is different from the original recipe as well. If I’m not getting all I am supposed to out of my base malt, I may not be getting it from my specialty malts, either.

Some brewers find this all very esoteric and only care about the qualities of the beer in their glass. If the color, flavor and alcohol level are satisfactory, they are happy with that particular batch of beer and this question is a moot point. Other brewers want to produce that same glass of beer indefinitely and the question becomes much more pertinent. These brewers will not only chart original gravity, but also wort/beer color and special malt-related beer flavors using highly trained taste panels. This data can then be used to determine which malt weights need to be adjusted to keep the beer within the defined specifications.

Most homebrewers or small craftbrewers do not go that far with fine-tuning their recipes. When I think of recipes in this manner, it reminds me of what a recipe really is to most brewers and cooks. A recipe is simply a way of describing something that was previously made. I routinely brew an American-style unfiltered wheat that contains three pounds pale malt, 2.5 pounds wheat malt and 0.75 pounds unmalted wheat per five-gallon batch to give an original gravity of 11.25° Plato (1.045 SG). I hop this beer with Perle hops to about 18 bittering units and use Liberty hops for aroma. This is my recipe and it merely defines the ingredients used in the beer. That’s all any recipe does. I would be surprised if another brewer used this recipe and made a beer that tasted just like mine.

In my opinion, if a brewer or a cook uses another person’s recipe, they should think of the recipe as a general description. The most important quality of the finished product to most homebrewers is how good the beer tastes, not how similar the beer is to that described by the recipe. Unless you have tasted the beer the recipe is based on, you have no idea how close you have gotten to the target. If you are more challenged by hitting your target than just making a great glass of beer, then you will need to invest in some lab equipment and recruit your friends and family to participate in your numerous taste panels.

Like all brewers, I grapple with this same issue. I personally prefer to “tweak” the weight of base malt if I am trying to stay focused on my target specific gravity. After all, that’s what the base malt primarily contributes to the wort. If, on the other hand, my color is off target or the flavor of the beer lacks the intensity of a particular malt, I change my focus. Color and flavor variances are best addressed by fine- tuning the specialty malt portion of the recipe. It is most important to remember that the brewer is not the only person faced with the challenge of consistency. Specialty malts are typically described with rather large ranges. For example, I use a crystal malt called “Crystal 135-165° Lovibond.” That’s one heck of a range of color. If I brew a beer today and the malt is on the lower end of that range, and the same beer is brewed later and the malt falls toward the upper range, then the finished beers will not be the same color unless the recipe is tweaked.

This is one doozy of a question. In my own opinion, you can’t really fine- tune the special malts unless you know what the target is. For these grains, I would view recipes as the historic log that they are. Specific gravity is a target, however, and I do adjust my base malts to hone in on that variable.

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