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Take Control with Partial Mashing

If you are looking for a sure-fire way to make great homebrew without the commitment of a full mash, consider the benefits of partial mashing.

For a modest investment of time and very little in the way of equipment, you can get the flexibility and quality benefits of mashing with the convenience of extract brewing. Instead of mashing enough grain for a whole batch of beer, partial-mash brewers mash a small amount of pale grain, plus specialty grains for flavor and color — and use pale extract to reach the rest of their original gravity.

You can get excellent control of your gravity with partial mashing. And the method covers a multitude of gravity sins. For example if your mashing method is not quite right and you end up with wort that’s too thin, it matters little if you plan to derive fermentables from extract, anyway.

George Hummel has been brewing for 15 years and has seen hundreds of recipes come and go as the owner of Home Sweet Homebrew, a homebrew supply store in Philadelphia.

“Partial-mash brewing really gives you the best of both worlds,” Hummel says. “It offers the flexibility and control of full-mash brewing, without the total commitment of time and equipment. It also provides a nice safety net; in the event your mash is screwed up, you’ll still end up with plenty of fermentables by adding extract,” he says.

Hummel has won a wall full of ribbons, many of them for mash-extract beers. One of his trademark brews, “Big Ass Beer,” regularly fools experts at festivals and beer tastings. “People taste it and can’t believe it’s got extract in it. It has all the taste attributes of all-grain beer but is easier to make,” he says.

One advantage of completing a partial mash is that you can use adjuncts with full confidence. The conversion power of the barley malt is enough to convert other starches in the malt, even pure corn starch. Flaked barley, unmalted wheat, rice, maize, and any other adjunct grains are safe to add to the partial-mash recipe.

Advice From a Pro

Don Gortemiller is brewmaster at the Pacific Coast Brewing Co. in Oakland, Calif. Pacific Coast is an extract brewery. But that has not stopped Gortemiller’s beers from winning many awards, including gold, silver, and bronze medals from the Great American Beer Festival. For a time, Pacific Coast had the longest GABF winning streak of any brewery in the United States.

Gortemiller offers a variety of tips to keep mash-extract beer at its best.

“What often happens when the homebrewer goes from an extract to a grain brewer is that he throws away his old, crappy equipment and starts using some decent gear,” Gortemiller says.

The old, scratched plastic bucket is traded for the glass carboy. The rusty, chipped enamel brewpot gives way to a nice stainless steel pot. A heat exchanger shows up. Gortemiller says these improvements in the brewhouse contribute more to improved homebrew than simply the switch from extract to grain.

But he adds that adding mash to extract recipes really helps, too, under the right circumstances. “The single most important aspect is probably the quality of the extract,” he says.

Gortemiller uses only fresh extract in his brewery, and he only buys enough to get him through three to four weeks of brewing, so the turnover rate keeps it in top condition. “It’s also important to store it in a cool, dark place. Extract can go moldy or even start to ferment if it is stored improperly. The cans that are available in the homebrew store are probably pretty good in terms of stability. Just be sure they are fresh when you buy them,” he says.

Gortemiller likes extract that’s neutral. It gives him a blank canvas to which he adds style, flavor, and color components with the mini-mash. “Good extract leaves no big calling card in the finished beer. Our string of awards attests to that,” he says.

Fresh grain is as important as fresh extract. “It may seem economical to buy grain in a 50-pound sack for homebrewing. By the time you get to the bottom of that bag, the grain is not going to be that good,” he says.

Both Hummel and Gortemiller agree that boiling the full volume of wort and force-chilling are keys to success with any recipe. “I can’t stress to homebrewers enough the importance of fast chilling,” says Gortemiller. “Trying to cool the wort with an ice bath — or worse, just letting it sit around for hours — is an invitation to contamination,” he says.

Adding grains to your recipe can improve fermentation characteristics, too. “The extract process removes key vitamins and other nutrients that the yeast need for vigorous fermentation. A mini-mash is a good way to get some of those nutrients back into the kettle. However, even with partial-mash brewing, I recommend adding yeast nutrient. We do it here and it has always served us well,” Gortemiller says.

Getting Started

One of the nice things about mashing a small amount of grain is that it requires little in the way of space or specialized equipment. A small cooler or an old brew bucket make fine mash tuns. You will need to create a false bottom for straining the mash. The commercial ones available at the homebrew shops are primo. But if you are thrift-minded, you can make your own with a piece of brass or copper tubing and some old siphon hose.

A five-gallon bucket is plenty big enough to hold your mash and all your sparge water, so you do not even have to worry about trickle sparging. You will lose some temperature if the bucket is not insulated.

The other equipment you will need is an accurate thermometer, your brewpot, and a second large stock or soup pot for heating sparge water.

When you have chosen your recipe, crush the grains and add a quart of water to your brewpot for every pound of grain you plan to use. Leave the grain aside, for the moment. Bring the water up to around 170° F and add the grains a little at a time, stirring constantly.

You want the temperature to drop to around 150° F. If it stays too hot, add a little cold water. If it’s cold, turn on the heat and stir constantly until the temperature is right. Taste it. It will be slightly sweet, cloudy, and very starchy.

Hold the grains at 150° F for around 45 minutes to give the starch in the malt a chance to convert to fermentable sugars. This can be achieved in one of two ways. The first is to cover the mash and keep it over very low heat on the stove, stirring and checking the temperature frequently. The second is to place the whole covered pot in the oven, set at the lowest setting — around 200° F for the average oven. You still will have to stir and monitor the temperature if you use the oven method, but it lessens the risk of overheating and scorching the grain.

When the mash period is over, taste the mash. It should be very sweet and have a thinner, clearer consistency than when it started. At this point you could perform an iodine test as an indicator of whether starch-to-sugar conversion is complete, but it is not essential. Simply scoop out a teaspoonful of mash and place it in a white plate or bowl. Add a few drops of tincture iodine or iodophor. If the conversion is complete, the iodine will stay reddish-brown. If starch is still present, it will turn blue-black. If the iodine test fails, recheck your temperature and continue with the mash until the grain is fully converted. Be sure to discard the sample. Iodine is one thing you do not want in your beer.

Toward the end of the mash period, bring your sparge water to a boil.

When the mash is done, take the sparge water off the heat for a few minutes so the temperature drops below 212° F. If you sparge with boiling water, you run the risk of leaching bitter, astringent tannins from the grains. The temperature of the water hitting the grains should be cooler than 172° F.

Close the crimp on the lauter tun hose. Pour a gallon or so of sparge water into the lauter tun, then gently transfer the mash to lauter. Let the mash settle. While you are waiting, wash your brewpot.

It’s time to vorlauf (recirculate). Hold a bowl, pot, or large measuring cup under the lauter hose and open the crimp. When the container is full, close the crimp and pour the wort back into the lauter tun. Do this three or four times, until the wort runs clear. Carefully add the rest of the sparge water and let the grain settle.

Position your brewpot under the lauter tun. You can put it on a chair, with the lauter tun on the counter. Open the crimp just a crack. You want a slow trickle of wort, not a full rush.

Take a break while the lauter runs dry. It should take at least 20 minutes, maybe half an hour.

When all the wort is in the brewpot, add your extracts, mix well, bring to a boil, and add hops according to the recipe.

Drain Bamage: Strong Belgian Ale
(5 gallons, partial mash)

Corn starch gives this strong ale an extra kick. The pale malt has enough enzymatic power to convert the corn starch to sugar. This is a great partial-mash recipe, because the adjuncts and lots of extract add tons of original gravity to the rich-flavored mini-mash.

Ingredients:

• 3.5 lbs. pale malt
• 0.5 lb. crystal malt, 40° Lovibond
• 1 lb. corn starch
• 0.5 lb. flaked barley
• 1 lb. dark brown sugar (or dark candi sugar)
• 6 lbs. pale extract syrup
• 1.25 oz. Hallertauer hops (4% alpha acid, 5 AAUs): 0.825 oz.
(3.3 AAUs) for 60 min., 0.425 oz. (1.7 AAUs) for 15 min.
• 1.25 oz. Fuggle hops (4% alpha acid, 5 AAUs): 0.825 oz.
(3.3 AAUs) for 60 min., 0.425 oz. (1.7 AAUs) for 15 min.
• 2 Tbsp. Irish moss
• Yeast nutrient
• Belgian ale yeast (liquid culture)
• 2/3 cup corn sugar for priming

Step by Step:

Bring 5 qt. water to 170° F in your brewpot. Add crushed grains, barley, and corn starch. Mix well. Hold at 150° to 155° F for 45 min. to 60 min., or until the mash passes iodine test.

To sparge bring 2 gal. water to a boil in a separate pot. Let it stand off the heat for a few minutes to allow the temperature to drop below 212° F. With the lauter spigot closed, add a few quarts of sparge water to the lauter tun, then the mash, and let it settle. Wash the brewpot while you let the grains settle. Vorlauf (recirculate) to set the grain bed and then add the remaining sparge water. Drain the mash tun slowly into the brewpot.

Add to the run-off the brown sugar, extract, and enough water to bring level to 6.5 gal. Stir well and bring to a boil. Total boil is 60 min. At start of boil add 0.825 oz. Hallertauer hops and 0.825 oz. Fuggle hops. Boil 45 min. Add 0.425 oz. Hallertauer hops, 0.425 oz. Fuggle hops, Irish moss, and yeast nutrient (amount based on manufacturer’s guidelines). Boil 15 min. more. Chill to 70° F and pitch yeast.

Ferment at 70° F for seven to 10 days. Transfer to secondary for 14 to 21 days. Prime and bottle.

OG = 1.070   FG = 1.012 to 1.014   Bitterness = 35 IBUs

Hail Britannia Special Bitter
(5 gallons, partial mash)

The freshness, snap, and bright malty flavor of English bitter is captured with the partial mash.

Ingredients:

• 1.5 lbs. pale English malt
• 4 oz. wheat malt
• 6 oz. crystal malt, 60° Lovibond
• 5 lbs. pale malt extract
• 1 oz. Northern Brewer hop pellets (9% alpha acid,
9 AAUs) for 60 min.
• 0.75 oz. Fuggle hop pellets (4% alpha acid, 3 AAUs) for 20 min.
• 1.5 oz. Goldings hops (4% alpha acid, 6 AAUs) for 5 min.
• 2 Tbsp. Irish moss for 15 min.
• Yeast nutrient
• English ale yeast
• 2/3 cup corn sugar for priming

Step by Step:

Bring 2 qt. water to 170° F in your brewpot. Add crushed English malt, wheat malt, and crystal malt. Mix well. Hold at 150° to 155° F for 45 min. to 60 min., or until the mash passes iodine test. Sparge as described in the Drain Bamage recipe.

Add extract and enough water to bring volume to 6 gal. Stir well and bring to a boil. Total boil is 60 min. At start of boil, add 1 oz. Northern Brewer hop pellets. Boil 40 min. Add 0.75 oz. Fuggle pellets. Boil 5 min. more and add Irish Moss and yeast nutrient. Boil 10 min. more and add 1.5 oz. Goldings hops. Boil 5 min. more. Chill to 70° F and pitch yeast.

Ferment at 70° F for five to seven days. Transfer to secondary for 14 to 21 days. Prime and bottle.

OG = 1.045    FG = 1.010    Bitterness = 45 IBUs

Baby,It’s Kölsch Outside German Ale
(5 gallon, partial mash)

Ingredients:

• 2 lbs. pale two-row
• 1 lb. Vienna malt
• 4 lbs. pale malt extract
• 2/3 oz. Perle hop pellets (8% alpha acid, 5 AAUs) for 60 min.
• 2 Tbsp. Irish moss for 15 min.
• Yeast nutrient (amount according to manufacturer’s guidelines)
• Continental ale yeast, liquid culture
• 2/3 cup corn sugar for priming

Step by Step:

Bring 3 qt. water to 170° F in your brewpot. Add crushed two-row and Vienna malts. Mix well. Hold at 150° to 155° F for 45 min. to 60 min., or until the mash passes iodine test. Sparge as described in the Drain Bamage recipe.

Add extract and enough water to make 6 gal. and bring to a boil. Total boil is 60 min. At start of boil, add Perle hops. Boil 45 min. and add Irish moss and yeast nutrient. Boil 15 min. more. Chill to 70° F and pitch yeast.

Ferment at 70° F for five to seven days. Transfer to secondary for 14 to 21 days. Prime and bottle.

OG = 1.048    FG = 1.010    Bitterness = 22 IBUs

George Hummel’s “Big Ass Beer”
(10 gallons — two 5-gallon batches, all-grain and extract)

For festivals and events Hummel uses a 10-gallon fermenter for bigger batches. Since his mash tun only accommodates five gallons, he brews two concurrent batches and blends them in the same primary.

It’s an all-grain batch with doubled up specialty grains, followed by an all-extract batch with the same hop schedule. Quantities can be halved for a five-gallon batch.

Batch 1 Ingredients:

• 5 lbs. two-row Klages malt
• 1 lb. Victory malt
• 1 lb. Munich malt
• 1 lb. carapils malt
• 1 lb. crystal malt, 30° to 40° Lovibond
• 1 oz. Columbus hops (12% alpha acid, 12 AAUs) for 60 min.
• 2 oz. Mt. Hood hops (4% alpha acid, 8 AAUs) at end of boil

Batch 1 Step by Step:

Bring 9 qt. water to 170° F in your brewpot. Add crushed malts. Mix well. Hold at 152° F for 90 min. to 120 min., or until the mash passes iodine test. Sparge as described in the Drain Bamage recipe.

Add enough water to make 6 gal. Bring to a boil. Total boil is 60 min. At start of boil add Columbus hops. Boil 60 min. At end of boil add Mt. Hood hops. Chill.

Batch 2 Ingredients:

• 8 lbs. Alexander’s pale malt extract
• 1 oz. Columbus hops (12% alpha acid, 12 AAUs) for 60 min.
• 2 oz. Mt. Hood hops (4% alpha acid, 8 AAUs) at end of boil

Batch 2 Step by Step:

Bring 6 gal. water to a boil, remove from heat, and add extract. Return to boil. Add Columbus hops and boil 60 min. At end of boil add Mt. Hood hops. Chill.

Combining Ingredients:

• Wyeast 1272 (American ale II)
• 11/3 cup corn sugar for priming

Combining Step by Step:

Combine the two batches and pitch yeast.

Ferment at 70° F for five to seven days.

Transfer to secondary for 14 to 21 days. Prime and bottle.

Issue: November 1999