Introduction to Parti-Gyle Brewing
The parti-gyle technique comes up more than expected when I talk brewing with folks. For the most part these conversations are almost exclusively with homebrewers, but there are a few professional breweries that occasionally take part in the practice of parti-gyle brewing. Still, the only reason this technique exists enough to discuss is because of homebrewers. We homebrewers often carry the torch of history forward, lest we forget the historic styles and brewing techniques of the brewers that came before us. Not to mention parti-gyle is a pretty cool way to brew.
Without this technique, we wouldn’t have the strong and common ales of England, as well as the enkels, dubbels, and tripels of Belgium. These styles have lived on long passed their “usefulness,” to the benefit of beer drinkers the modern world over.
So here we are, well past the industrial revolution that changed brewing forever, and allowed brewers to use the whole mash in a single beer. Is parti-gyle an essential brewing technique? No. Yet the technique still makes a lot sense on many occasions and instances. Variety is the spice of life, so why brew one beer, when you could brew two or more? You can be adventurous, brewing strong beers and session beers simultaneously.
Traditional Parti-Gyle Method
Think about handling a large commercial-sized batch back in the day. They didn’t have efficient energy systems like electricity, boilers, and steam jackets, nor did they have the fuel to efficiently direct fire their kettles. Siphoning and gravity directed beer from vessel to vessel for our brewing forefathers. The act of mashing the grains required less fuel and technology, as they weren’t boiling the wort. The mash could be done in a large wooden vessel, which were relatively easy to construct. These wooden tuns were insulated well enough to effectively mash the grains. What was harder was to build large boil kettles, as well as create enough heat for a large kettle, so boils were much smaller volume-wise than mashes. This lead to multiple boils from a single mash, the basis of parti-gyle brewing. The word “gyle” as defined in the Merriam-Webster Dictionary states “the beer produced at one brewing,” which comes from Middle English but has roots in the Dutch language. The exact root of the word “parti” is more obscure, but seems to be Latin-derived and could represent part, portion, or a division of one gyle.
You do have to go back a ways to find this technique in everyday use at most breweries. During the late 1700s the “entire” method was developed in England with the advent of large kettles being produced, and changed the brewing game forever. “Entire” brewing runs all of the wort to one kettle. Sound familiar? Minus maybe a few traditional breweries in the United Kingdom, and a few creative craft brewers in the United States that may employ parti-gyle brewing from time to time, “entire” is the technique employed by almost all breweries today.
We’ll use a historical example to see what a traditional parti-gyle looked like. Perfectionists beware, calculating color and gravity for your beer can be a bit more of a estimation, rather than a science. Understanding that there are a lot of minor factors that can change the final outcome is a disclaimer that all brewers need to comprehend before partaking in a parti-gyle brew session.
Harken back to old Scotland, let’s say the year is 1700, a time when parti-gyle was a popular technique. We’ll start with a wee heavy, a big Scottish beer with lots of malt character. Due to the gravity of this beer, if a brewer were to make it using the traditional single-kettle beer approach, they may end up leaving a large amount of sugar behind in the mash tun. Or, more commonly, a brewer won’t want to waste much sugar from their grain bill, and they’ll attempt to sparge out every last ounce of sugar from the mash. This requires a lot of water, and multiple-hour boil to reach the target gravity. It also means that there’s little room for error in terms of mash efficiency.
Determining the Malt Bill
We know we want to brew a wee heavy. A good starting gravity for this style lands brewers around 1.096. Let’s say we want 5 gallons (19 L) of wee heavy, and we have a second kettle and burner that can handle an additional 10-gallon (38-L) batch. The plan then is to make a grand total of 15 gallons (57 L) of beer, splitting into a high gravity beer with the first 1⁄3 of the wort run out of the mash tun, and later 2⁄3 runnings used to brew a low gravity beer. This is fairly common practice, and you’ll find many historical style gravities follow a similar division of the wort.
The general rule on a 1⁄3 -2⁄3 split like this is that your first runnings (33% of the batch) will contain twice the gravity as your second runnings (67% of the batch.) Using that as our guideline, a 5-gallon (19-L) parti-gyled wee heavy with a target original gravity of 1.096, should produce 10 gallons (38 L) of second runnings around 1.048. This is a great target gravity for a Scottish export style beer.
To determine the necessary grain bill, we’ll need to do some basic math to calculate our target gravity over our entire 15-gallon (57-L) batch. We’ll use our gravity point (GP) multiplied by our desired batch size, divided by our entire batch size. So 96 GP multiplied by 5 gallons (19 L), and 48 GP multiplied by 10 gallons (38 L), divided by our entire batch of 15 gallons (57 L) calculates out as:
(96 GP x 5 gal.) + (48 x 10 gal.) / 15 gal. = 64 GP
or utilizing metrics:
(96 GP x 19 L) + (48 x 38 L) / 57 L = 64 GP.
We now know our target gravity for 15 gallons (57 L) of wort should be 1.064. Let’s write a grain bill for this Wee Heavy and Scottish Export! (full recipe found below)
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Parti Like It’s 1700 — Wee Heavy & Scottish Export Grains
15 gallons (57 L)
Target OG = 1.064 (15.7 °P)
38 lbs. (17.2 kg) English pale ale malt
5 lbs. (2.27 kg) caramalt (10 °L)
0.5 lb. (227 g) roasted barley (550 °L)
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When plugged in to a recipe calculator using the BYO recipe standards of 65% extract efficiency, this malt bill shows 16 SRM color. I find a good general rule for color is to estimate about 50% greater than 16 SRM in color for the first runnings, and 50% less color for the second runnings. This means our first 5 gallons (19 L) of wee heavy should be around 24 SRM, and our Scottish export will end up around 8 SRM. This is a bit light for the Scottish export, which calls for a minimum SRM of 13. Color is tricky to estimate as it can change based on the size of your batch, the division of your runnings, and the type of malt you used. I like using this calculation when brewing a 1⁄3 to 2⁄3 batch spilt, as I need the reminder that my second beer may not have the color my first batch managed.
At this point, let’s make the decision to adjust our color of the second runnings. English carastan malt (34 °L) would make a nice choice. We’ll need two pounds (0.91 kg) to get the color we desire. The carastan should add about 6 SRM in color and 4 gravity points to my 10-gallon (38-L) batch, giving me a slightly larger 1.052 gravity Scottish Export around 12 SRM in color. We’ll add these ‘cap grains’ on top of the existing mash once we’ve completed the necessary run-off for the wee heavy.
This cap grain addition will also help further differentiate the flavor of these beers. We’ll mix these right in to our mash and let them hydrate for 15 minutes when the wee heavy batch is in the boil kettle.
Now that we’ve determined our grain bill, we’ll still need to determine our hops and yeast for two boils and batches. This is our opportunity to even further differentiate these beers, and give ourselves two unique options from a single mash to drink and share. Let’s choose to use the same Scottish ale yeast, since they’re both in the Scottish style and few options exist. Our traditional hop options are a bit more diverse. Let’s use Kent Goldings in our wee heavy, and Fuggle in our Scottish export.
Other Considerations
Obviously this isn’t a small recipe. We’re brewing two beers with a bit of gravity to them, and 15 gallons (57 L) in total. We’ll need a large enough mash tun to handle 45.5 lbs. (20.6 kg) with our cap grains. (To calculate how much grains your mash tun can hold, visit www.rackers.org/calcs.shtml to utilize the Green Bay Racker’s “Can I Mash It” mash tun calculator.) Because we’re brewing two beers, and using this technique to more easily make a high-gravity beer, doesn’t mean our output has to be this big. If you’re set up to brew 10-gallon (38-L) batch sizes, you may find you have enough room in your mash tun to handle 1⁄3 to 2⁄3 split at 9 gallons (34 L) — 3 gallons (11.4 L) of a high-gravity first runnings, and 6 gallons (22.7 L) of a more sessionable beer. Find out what your system can handle and scale from there.
Another practical consideration is a second boil kettle. Some brewers parti-gyle with a single kettle, and this is possible. You may find this extends your brew day beyond what you had hoped. I’ve found it much easier to begin my first boil, then run-off my second runnings into a large kettle, and begin the second boil before completing my first beer. Balancing your time takes some thought, but isn’t difficult if you’ve prepared all of the equipment and ingredients you need.
Whether you batch sparge, fly sparge, or use another technique, don’t change it for parti-gyling. If you do choose to batch sparge, be sure to think about your mash as two separate beers and calculate water needs appropriately. If you fill and drain your mash tun and don’t end up with enough liquid, don’t just fill the entirety of your mash tun again. Be mindful of dilution of your sugar and color in the mash tun — use the appropriate amount of water, or you may have to boil longer to hit your gravity. This is true of both the first and second runnings.
Alternative Divisions for Parti-Gyle
There’s more than one way to skin a cat . . . or should I say, brew parti-gyle. A 50/50 even split of your runnings works well too. This sort of division means you’ll have two equal volumes of beer, but gravity will not be equal. A good general rule is that your gravity of the first-runnings will be 58% of your potential gravity, your second-runnings the remaining 42%.
Let’s say we’re brewing a 10-gallon (38-L) batch at 1.060, and we decide we really don’t want 10 gallons (38 L) of one beer sitting around right now. We take our 10 gallons (38 L) and multiply that by our 60 GP. We’ll multiply that by our percentages, and divide our batch so that the 50/50 split runnings formula would look like:
10 gal. x 60 GP = 600 GP • gal.
or if using metrics:
38 L x 60 GP = 2280 GP • L
Now to calculate SG of each portion:
(600 x 58% of total gravity) / 5 gallons = 1.070 first-runnings gravity
(600 x 42% of total gravity) / 5 gallons = 1.050 second-runnings gravity
or if using metrics:
(2280 GP • L x 0.58 percent of GP) / 19 L = 1.070 first-runnings gravity
(2280 GP • L x 0.42 percent of GP) / 19 L = 1.050 second-runnings gravity
Another way to split your batch would be into three equal portions. This is a traditional method that also typically used some blending of the three batches during cellaring to get three different beers. When you have three different beers, the blending opportunity is that much greater to really dial in the flavors on your beers.
Equal thirds will give you three batches of the same volume, and some easy math in terms of gravity. Let’s say we have a 6-gallon (22.7-L) batch of 1.060 wort, and we want to make three beers. A general rule of thumb is that the first runnings will be 50% greater than the entire batch gravity. Your second-runnings should be equivalent or the same as the expected entire batch gravity. The third batch should be half of your entire batch gravity. In this scenario we’d have 2 gallons (7.6 L) of first-runnings at 1.090, 2 gallons (7.6 L) of second-runnings at 1.060, and 2 gallons (7.6 L) of our final-runnings at 1.030.
Parti-on Homebrewers
There’s a lot of room for experimentation with parti-gyling. Where and how you split your batch is up to you, and will determine the flavor, color and gravity of your worts. Maybe you want to try collecting your first 2⁄3 of the runnings in order to make a larger, stronger batch. Calculations may be a bit more difficult, but maybe exact numbers are less important to you than experimentation and flavor. Don’t be afraid to experiment with the cap grains to change color and flavor for later runnings. You can always add sugars, syrups, malt extracts to adjust the gravity or add other adjuncts to adjust flavor profile. Blending of your beers may bring you even closer to parti-gyle perfection.
Parti-gyling can be a very useful and practical technique for the homebrewer. It’s a weapon in our brewing arsenal we can more easily use than larger brewers who have commercial sales and big equipment and cost considerations. The bigger beers will require less water and boil time, and the ‘last drops’ of gravity gets used in a second beer. The added variety adds further drinking and sharing options. I recommend that you try to add this historic technique to your next brew day.
Parti-gyle recipe
Parti Like It’s 1700
(15 gallon/57 L, all-grain)
Average OG = 1.064
Wee Heavy (First Runnings)
(5 gallons/19 L)
OG = 1.096 FG = 1.023
IBU = 22 SRM = 24 ABV = 9.2%
Scottish Export (Second Runnings)
(10 gallons/38 L)
OG = 1.052 FG = 1.013
IBU = 24 SRM = 13 ABV = 5.1%
This recipe uses a 1⁄3 and 2⁄3 split of the mash, with the smaller volume Wee Heavy collected first and the larger volume Scottish Export being collected second.
Ingredients
38 lbs. (17.2 kg) English pale ale malt
5 lbs. (2.27 kg) caramalt (10 °L)
0.5 lb. (227 g) roasted barley (550 °L)
2 lbs. (0.91 kg) carastan malt (34 °L) (cap grains)
7 AAU Kent Goldings hops (60 min. – Wee Heavy) (1.4 oz./40 gat 5% alpha acids)
12 AAU Fuggle hops (60 min. – Scottish Export) (2.5 oz./71 g at 4.8% alpha acid)
4 packs White Labs WLP028 (Edinburgh Scottish Ale) yeast
2 cups corn sugar (if priming)
Step by Step
Mill the grains, holding the carastan malt separately. Dough-in the pale ale malt, caramalt, and roasted barley, targeting a mash of around 1.2 quarts of water to 1 pound of grain (2.5 L/kg) and a temperature of 152 °F (67 °C) using 13 gallons (49.4 L) of water at 166 °F (74 °C). Hold the mash at 152 °F (67 °C) until enzymatic conversion is complete, about 60 minutes. In your hot liquor tank, bring 15.1 gallons (57 L) of sparge water up to 170 °F (77 °C). Sparge slowly with 170 °F (77 °C) water, collecting wort until the pre-boil kettle volume is 6 gallons (22.7 L), you should use about 5.1 gallons (19 L) of sparge water. If taking a gravity reading, your pre-boil gravity should be 1.080 to achieve 1.096 at 5 gallons post-boil. Add 1.4 oz. (40 g) Kent Goldings hops once a boil is reached. Total boil time is only 60 minutes.
During this first runnings boil, add the 2 lbs. (0.91 kg) carastan (34 °L) malt to cap grains in the mash tun. Stir in to wet and solubilize the protein and sugar in the grain. Let rest for 15 minutes. Take your additional 10 gallons (38 L) of 170 °F (77 °C) sparge water and add slowly, draining wort to a second kettle until 12 gallons (45 L) is collected. If taking a gravity reading, your pre-boil gravity should be 1.044 to achieve 1.052 at 10 gallons (38 L) collected post-boil. Add 2.5 oz. (71 g) Fuggle hops once a boil is reached. Total boil time is 60 minutes.
Chill both worts to 68 °F (20 °C) and aerate thoroughly. Pitch 2 packages of yeast into each batch. Ferment in primary at 68–70 °F (20–21 °C) for two weeks. The Scottish export may be ready to bottle or keg after two weeks. Continue fermenting the wee heavy for an additional 2 weeks to 2 months in a secondary fermenter. Bottle or keg as usual.
