Converting Recipes
You have probably faced this problem one way or the other, and maybe it looked to be intractable to you. Say you’re an extract brewer and you want to brew a beer for which you only have an all-grain recipe. Perhaps it was a prize-winning beer or you got the recipe from a craft brewer for your favorite beer. How do you convert this recipe into one based on malt extract? Or vice versa, you have a highly-praised extract-based recipe and you want to brew it using all-grain — perhaps you are moving onto all-grain from extract brewing and want to convert your own prize recipes to one for a full-mash brew. Well, it isn’t so difficult to do and even a rocket scientist should be able to handle it! It does take some calculations and even some simple equations, but don’t be put off, as they are mainly common sense procedures that can be done manually, although a calculator is always helpful.
Converting gravity
The first step is to make the original gravity match that of the recipe you have. Malt extract and grain malts do not give the same yield on a pound for pound basis, so we have to work on the basis of gravity points. By gravity points I mean (specific gravity x 1,000) – 1,000, so a specific gravity (SG) of 1.053 represents 53 gravity points. Now in our conversion the weight of grain multiplied by its extract yield must equal the weight of malt extract multiplied by its extract yield. By extract yield I mean the gravity points yielded by 1 lb. (0.45 kg) of malt or malt extract dissolved in 1 gallon (3.8 L) of water.
If you do not know how to determine the extract yield you can find it listed in BYO’s Recipe Standardization (listed on page 4 of every issue of the magazine). This does assume a 65% brewery efficiency in the case of grains, which is what I shall use in this article. If your efficiency differs from this you should try to obtain it from the brewer who gave you the recipe, or calculate it yourself from your own brewing. You’ll find it helpful to consult the “Grains and Adjuncts Chart” at www.byo.com, which will give you the maximum yield of most grains you are likely to come across, as well as those for malt extracts (look under sugars for those).
So let’s look at an example of a recipe brewed only from pale malt. So suppose you want to make a malt extract brew to match the recipe that calls for 12 lbs. (5.4 kg) pale malt in a 5-gallon (19-L) brew. The BYO recipe standardization tells us that at 65% brewhouse efficiency 1 lb. (0.45 kg) in 1 gallon (3.8 L) of water yields an SG of 1.024, and (1.024 x 1,000) – 1,000 = 24 gravity points. Therefore the total points in this case are 12 x 24 = 288, and this is what you want to get from your pale malt extract.
BYO’s chart tells us liquid malt extract will yield in the range 1.033–1.037 for 1 lb. (0.45 kg) in 1 gallon (3.8 L) of water. You may be able to find the exact figure from a manufacturer’s website, but this is not always the case. So if you are not sure, we can just take the mid-point of the range, that is 1.035, or (1.035 x 1,000) – 1,000 = 35 gravity points. Therefore the weight (W) of malt extract you need is given by:
W x 35 = 288
and then
W = 288/35 = 8.2 lbs. (3.7 kg)
Of course, you may not want to weigh out a fraction of malt syrup, so suppose you had a 6 lb. (2.7 kg) package and wanted to make up the rest with dried malt extract (DME). Well, the 6 lbs. (2.7 kg) of syrup would yield (6 x 35) = 210 gravity points. But we wanted a total of 288, so the DME needs to provide (288 – 210) = 78 points. Now BYO tells us that 1 lb. (0.45 kg) of DME in 1 gallon (3.8 L) of water gives an SG of 1.045, or (1.045 x 1,000) – 1,000 = 45 points, so the required weight of DME (WD) is given by:
WD = 78 / 45 = 1.7 lbs. (0.79 kg)
So our extract recipe requires a total of 6 lbs. (2.7 kg) extract syrup and 1 lb. 12 oz. (0.79 kg) DME.
This is based on 65% efficiency, so the gravity points of the 5 gallons (19 L) of wort would then be 288 / 5 = 57.6, and OG would be (57.6 + 1000) / 1000 = 1.0576, rounding to 1.057. If, in fact, the brewer’s efficiency differed from 65% but you had the OG, then the exercise of conversion becomes simpler. Ignore the grain weight and extract yield and just calculate the gravity points needed as (OG – 1,000) x 1,000), and proceed as above to calculate the amount of malt extract needed.
Converting from extract to grain is just as simple, providing that your grain brewing efficiency is 65%, because you just then reverse the approach outlined above. But what if you don’t know that efficiency because you have up till now been an extract only brewer? Well, you won’t go far wrong by assuming that it will be close to 65% for a first shot, and if your efficiency is different from that, calculate what it actually is and tweak the recipe accordingly for the next brew.
Calculating efficiency in all-grain brewing is another thing that might seem unnecessarily complicated but isn’t really so. All you need to do is compare your original gravity for a given beer with that which you would get if you got the maximum possible yield from the grain. That figure can again be found from BYO’s two online charts. So let’s go back to the example above, this time converting back from extract to grain. At a 65% efficiency 6 lbs. (2.7 kg) extract syrup and 1 lb. 12 oz. (0.79 kg) DME would convert to 12 lbs. (5.4 kg) of pale malt and the OG would be 1.057. Suppose you brewed this beer and got an OG of 1.065, which means a total of (1.065 x 1,000) – 1,000 x 5 = 325 gravity points. From the charts the maximum yield for 2-row pale malt is an SG of 1.037 for 1 lb. (0.45 kg) in 1 gallon (3.8 L) of water. So our total points from 12 lbs. (5.4 kg) would be (1.037 x 1,000) – 1,000 x 12 = 444, so:
Efficiency = (325 / 444) x 100 = 73%
Or, in other words, what you are getting is 73% of 1.037, or 1.027 for 1 lb. (0.45 kg) of malt in 1 gallon (3.8 L) of water, and this is the number you should use in the conversion calculations.
Going further
The earlier example used only one malt, pale 2-row or pale extract syrup, but it is more likely that you would want to convert a more complicated grain recipe, one using more than one base malt, and/or specialty malts and adjuncts. If so, when you convert to a malt extract recipe you will have to decide whether you require a partial mash step, or whether just a hot water steeping will do.
Anything containing starch has to be treated by a partial mash procedure. These include Munich, Vienna, rye, wheat, and peat-smoked malts when these malts are present in the original recipe as “flavor enhancers,” that is in amounts of a pound (0.45 kg) or so in a 5-gallon (19-L) brew, rather than as base malts. These malts can all be mashed directly, whereas others, such as brown and amber malts and adjuncts such as flaked maize, oats, and rice contain starch and must be handled in a partial mash along with a portion of pale malt to provide enzymes for starch conversion.
Roasted grains, in general, do not require mashing; steeping in hot water is all that is needed to extract their flavor, color, and fermentable sugars. These include crystal/caramel malts, Belgian Caravienne and Special B, chocolate and black malts, and roasted barley.
So, I’ll use an example for Ruby Mild, a beer I recently brewed at Brewport, which was a riff on an early 20th century English mild ale. Here’s the recipe for 5 gallons (19 L):
OG=1.056 FG=1.014 ABV=5.5% IBU=29 SRM=40
9.5 lbs. (4.3 kg) pale 2-row malt (2 °L)
12 oz. (0.34 kg) crystal malt (60 °L)
12 oz. (0.34 kg) Victory® malt (25 °L)
10 oz. (0.28 kg) brown malt (55 °L)
4 oz. (113 g) chocolate malt (350 °L)
For the record, if you want to brew this beer, I used 1 oz. (28 g) of UK Challenger hops at 7.8% alpha acids and 2 packs of Safale S-04 English ale yeast.
But now let’s convert that to a malt extract recipe, starting with the fact that brown malt contains starch so this will require a partial mash step with 1 lb. (0.45 kg) pale malt. The other specialty malts should go into the partial mash for the sake of simplicity, and the gravity points obtained in this mash would be:
2-row pale malt = 1 x 24 = 24
Crystal malt = 0.75 x 22 = 16.5
Victory® malt = 0.75 x 22 = 16.5
Brown malt = 0.63 x 22 = 13.9
Chocolate malt = 0.25 x 22 = 5.5
Total gravity points from partial mash = 76.4, rounding to 76
Now, total gravity points = 5 x 56 = 280, so we require from the malt extract (280 – 76) = 204. With malt extract syrup that means (204/34) = 6 lbs. (2.7 kg). Since that is a nice round number we do not have to worry about DME in this case and the final malt ingredients are:
6 lbs. (2.7 kg) pale liquid malt extract
1 lb. (0.45 kg) 2-row pale malt
12 oz. (0.34 kg) crystal malt (60 °L)
12 oz. (0.34 kg) Victory® malt (25 °L)
10 oz. (0.28 kg) brown malt (55 °L)
4 oz. (113 g) chocolate malt (350 °L)
Put all the grains in a muslin bag and mash at 150–152 °F (66–67 °C) with 1 gallon (3.8 L) of hot water for 60–90 minutes. Strain off the liquor and rinse the grains twice with 1 gallon (3.8 L) of hot water, collect all three batches of wort, stir in the extract syrup and proceed with the boil as usual.
Variation
Let’s get a little more complicated and work out what you could do if you did not want to do a partial mash and preferred to use the simpler approach of steeping the grains. That means we have to eliminate the brown malt and I would do that by increasing the specialty malts to give a grain malt bill as follows:
9.5 lbs. (4.3 kg) pale 2-row malt (2 °L)
1 lb. (0.45 kg) crystal malt (60 °L)
1 lb. (0.45 kg) Victory® malt (25 °L)
6 oz. (170 g) chocolate malt (350 °L)
Now total gravity points from the specialty malt are:
Crystal malt = 1 x 22 = 22
Victory® malt = 1 x 22 = 22
Chocolate malt = 0.375 x 22 = 8
Total gravity points = 52
Now total gravity points = 5 x 56 = 280, so we require from the malt extract (280 – 52) = 228. With malt extract syrup that means (228 / 34) = 6.7 lb. (3 kg) of syrup will be needed. That’s an odd number, so let’s replace 0.7 lb. syrup with DME. We need (0.7 x 34) / 45 = 9 oz. DME to do that, and our recipe becomes:
6 lbs. (2.7 kg) pale liquid malt extract
9 oz. (0.26 kg) DME
1 lb. (0.45 kg) crystal malt (60 °L)
1 lb. (0.45 kg) Victory® malt (25 °L)
6 oz. (170 g) chocolate malt (350 °L)
In this case the specialty malts are steeped for about 30 minutes with 1 gallon (3.8 L) of hot water at 150–160 °F (65–71 °C). Strain off the liquid, rinse the grains twice with the same volume of hot water, dissolve the extracts in the collected worts and boil as usual.
This new recipe will not exactly match the partial mash recipe, for the beer will be a little darker and redder in color, and will lack the distinctive licorice notes coming from the use of brown malt. But it will be fairly close and the end result will still be an enjoyable Ruby Mild!
