How To Formulate Recipes / A Handy Brewlog

At the top of the form is a space to number and name your masterpiece, and record the date of its creation for posterity. The bulk of the form is arranged in two columns. Reading down the left column you will find the parts that pertain to the first brew day. The second column contains an area for general notes about the batch and boxes for information about the transfer to secondary and bottling. I keep my filled-in forms in a 3-ring binder and record my tasting notes on the backs. Let's go through the form in order, pretending to formulate and brew 5 gallons of oatmeal stout as we go.

First we come to the MALT section. We need to know the following things to fill this out:

1. What specialty grains we will use. I want to use .5 lbs of dark crystal malt (90 L), 1 lb of roasted barley, and 1 lb of flaked oatmeal (this is regular breakfast oatmeal, don't waste your money on the stuff at the brew store).
2. What OG we want. I want the OG to be 1.050.
3. What color we want the beer to be. See the color chart for guidelines. This beer will be >100(L.
4. What our mashing yield will be. What does this mean? Mashing yield refers to how much soluble material one is able to extract from the grains. This is usually measured in specific gravity points, typically, the number of thousandths of a unit of specific gravity in one gallon of water. For example, if you start with 5 gallons of plain water (SG=1.000) and end up with 5 gallons at SG=1.010, you added 10 points per gallon x 5 gallons = 50 points. I have included a table of the maximum number of points provided by a pound of various grains. These figures are rarely achieved. However, with care and good water treatment, 90% of these values is not hard to realize. To figure what your yield was you compute the maximum you might have obtained using the table (see below on filling in the form). You then figure how much you really obtained as in the example above. Divide the latter by the former and you have your yield. If this is unclear, read on.

Here is a hint for making things go well: If you underestimate your efficiency you are in a bit of trouble; you either need to dilute the wort to get the right OG, diluting out the effects of your specialty grains, or you can just live with the too-high OG. If you over estimate your efficiency, you can add a little pale malt extract, or even a little table sugar (sucrose) to make up the difference. If you keep the sucrose addition below 10% of all sugars added (<10% of the total points are from refined sugar) you will suffer no problems except a slight decrease in body. So guess a little (3%?) on the high side for your yield. If you are right--hooray! If not, jack up the OG with malt or sugar.

Although the color/gal doesn't directly impact how much of anything you use, if you find that you predict something way too dark or light for the style it is a good bet you have not formulated the recipe very well. Note that the lovibond measure is highly nonlinear and that this method only produces a rough estimate of the final color. I find that it is about 10% too high in the 10's and 20% too high in the 20's. See the final color table to compare your answer to some commercial beers. (If you see color listed as EBC you can convert to lovibond (which is the same as SRM): L=.37 EBC + .46)

But wait! I want to use up this can of Alexander's Light extract I got for Christmas. Looking at the table I see that it will provide 3.3 pounds x 36 points/pound = 119 points. Since this will always be at 100% yield, this should be subtracted from the "Exp. extract" blank, leaving 156. Now subtract 66 to get 90, divide by 35, and find that you need to add only 2.6 pounds of pale malt. The extract syrup gets recorded as a "Kettle adjunct" below in the BOIL box (since this is where it will actually be used) and its 119 points of extract gets recorded in "Extract extract" in the PITCH box. Using darker extracts is more complicated as you must reduce the specialty malts somewhat.

Grain Extract Table

Notes to table:

1. Includes US and UK, lager and ale malts, which are quite different from one another.

2. Includes malts known as caramel; cara-pils, -vienne, and -munich (Belgian crystals (~15, 22, and 75šL respectively)); and light carastan, carastan, and Scottish crystal (UK crystals (~20, 40, and 90šL respectively)).

3. Includes, in roughly increasing order of color, Victory, Biscuit, Amber, Brown, Special Roast. Different maltsters name these differently. Ignore the name and look at the color with lighter ones adding body, warmth, and complexity and darker ones adding complexity, color, and toastiness to burnt toastiness.

4. Diastatic malt extract has amylase enzymes (not to be confused with DME=Dry malt extract).

Final Color Table:

Now it is time for the BOIL. I boil for 90 minutes, adding hops 60 minutes before the end and at various times later on. I like to try to hit my desired final volume at the end of the boil, so I like to know how much I generally boil off. For this reason I record the starting volume. I record the clock time that the boil actually starts, which I use to calculate the remaining times. The preboil is the time of boil before the first hops addition (this is simply to allow me to figure the total boil time after the fact). I list any salts, sugar, flavorings, fruit, malt extract etc. I add during the boil in the "Kettle adjuncts" space.

Now for the fun part: the hops. Each line contains the information about 1 hop per addition. This is easiest to see by looking at the sample form. The w/p refers to the form of the hops: whole or pellets. The times are recorded next to the first hop of that addition. The Type, Ounces, and % Alpha columns are self-explanatory. See below for the last two columns.

To design the hopping schedule I start with the late hops. I choose the type, time, and amount of the late addition by the amount and type of hop character that I want. Any amount of hops from 1/4 of an ounce to 2 ounces added five minutes before the end of the boil will give me good hop aroma. Hops added at 15 before the end will still give that unmistakable hop flavor if at least 1/2 an ounce is used, and I sometimes will also add 1/2 to 1 ounce at 25 minutes for that subtle, mellow hop character that seems to get lost with lots of late hopping. As a very rough guideline for late additions (15 minute boil or less), 1/3 oz in a light beer or 1/2 oz in a stronger beer will just be noticeable. 1/2 oz and 3/4 oz respectively will be present but not strong, and twice these amounts will get you to quite hoppy. Additions at 25 minutes have about half the effect (a crude statement considering the great difference in character) of these later additions.

Once the late additions have been worked out, their contribution to bitterness is computed. Bitterness in beer is measured in international bitterness units, or IBU's. An IBU is a measured quantity of a beer. When homebrewers refer to the IBU's of their beer, they are usually only guessing. The fundamental uncertainty here is how much bitterness is extracted in the boil (this is called utilization). Many people have tried to quantify this for homebrewers, but the effort is really wasted. With different equipment and procedures, everyone's utilization will different. I have given a copy of the utilization curve I use. It seems to have good predictive power for my beers. If you don't have one already, try mine and modify it if it doesn't work for you. If you read the curve at the time of the hop addition you will get the utilization with some constants included. This number is what I call the "Time factor" on the sheet. If you fill this in, multiply by the weight in ounces and the % alpha acid (multiply by 5, not 0.05, for 5%), you will get an estimate of the IBU's contributed to 1 gallon.

If you know how many IBU's you are shooting for you can fill that in at the bottom. Various books, including Michael Jackson's, have IBU figures for various beers. I have included a short list spanning much of the range below. Note that bitterness will be more perceptible in weaker, less flavorful beers. Multiply your IBU's by your final boil volume to get a figure for how much bitterness you need to add. If you subtract the bitterness contributed by your late hops (which will probably be a small fraction of the total) you get how much needs to be added by the early addition.

Bitterness Examples Table: