To Partigyle

Some notes on the process for making a partigyle.  I did a couple of things wrong and a few things right on Batch 100, so I thought I'd write down what should have happened for future reference.

Partigyle is a way of making 2 beers out of one batch, one strong, one weaker. This is a great way to get more beer out of a high gravity beer recipe. The basic idea is to add enough water to the mash to get out enough wort for half a batch, run that into one kettle, then add enough water to the mash to get out enough wort for a second half batch, and run that into a second kettle. You can either keep them as they are, so one strong beer and one not-so-strong beer, or blend as appropriate to get just what you want. This does require some extra equipment, you'll need 2 boil kettles and 2 fermenters.

First, create a recipe of some sort, then enter the recipe OG into the calculator below. This will tell you the OGs of the two beers. The most common use cases are making a strong beer out of 1/3 and a somewhat smaller beer out of the other 2/3, or go half and half. Pro brewers in England often do 1/3, 1/3, 1/3 to get three beers, and blend a little to get exactly what they want, so they'll get a 6% beer, a 5% beer, and a 4% beer out of a single mash.

Partigyle Calculator

Recipe OG:

1/3 - 2/3 method

First runnings (1/3):

Second runnings (2/3):

Half and half method

First runnings (1/2):

Second runnings (1/2):

3 thirds method

First runnings (1/3):

Second runnings (1/3):

Third runnings (1/3):

You might have to adjust the recipe to get the individual OGs that you want. I have only done the half and half method, where I end up with 5 gallons of strong beer and 5 gallons of not-so-strong beer. For example, my recipe for a 10 gallon batch of End of the World has an OG of 1.070, I'll get 5 gallons of 1.093 End of the World beer and 5 gallons of 1.047 brownish beer.

Use both the HLT and BK to heat water.  Heat just enough in the BK for mash in.  Use whatever is appropriate for the recipe, but usually 1.25 - 1.5 quarts per pound of grain.  This will leave your BK empty and ready to receive the first runnings. Pay attention, if you try to mash with all the water necessary for the first runnings, you might overfill the mash tun. You can use somewhat less water, run some off, then add enough to complete the necessary volume.

Calculate 0.125 GALLONS per pound for grain absorption.  Use hot water from the HLT to get enough for the first running.  Example:

28.25 lbs grain
1.5 qts/lb x 28.25 = ~42 qts = 10.5 gallons

28.25 x 0.125 g/lb = 3.5 gallons lost to grain absorption

10.5 - 3.5 = volume of first running = 7 gallons.

Heat 10.5 gallons of water in the BK to mash in temp.  Use all of this water to mash in - or not, pay attention to your MT volume.

That should be about right for a 5 gallon batch with a 90 minute boil.  If it is more than you need, make the mash a little thicker by adding less water for mash in, maybe use 1.25 qts/lb instead of 1.5 qts/lb.  If it's not enough, add water from the HLT at the end of the mash (and maybe after running off some of the wort) to get exactly what you need.

Heat water for small beer in HLT at the same time water is heating in BK for mash in.  Heat a couple of gallons extra in case you need it to top off the first runnings.  Make sure there is at least enough for sparge for the small beer since the HLT is going to be the boil kettle for the small beer.  Better is to heat a couple of gallons extra, just in case you need it.  You don't need to account for absorption on this sparge since the grain is already wet, so just add exactly the amount of water you want in the kettle for the small beer.

Drain any remaining water in the HLT to a bucket.  You might want it in case you come up short after collecting the wort for the small beer.  If you get more wort than you wanted, collect it all and boil it down to the right volume (need a 3rd burner).  Otherwise, the beer will be smaller than you planned. Or use it to make a cider or for a yeast starter.

One mistake I made was I used whole hops and don't have a SS screen on my HLT, so the valve clogged right away when trying to drain into the fermenter.  I used a scrubby on the end of my racking cane and siphoned.  Next time, I'll either add a screen to the HLT or put the hops in nylons. (Update, I have screens on all 3 of my keggles now.)

Note: here are the formulas used in the calculator above:
1/3 - 2/3 method:
    1st Run 1/3 = 1 + (3 / 2) * (og - 1)
    2nd Run 2/3 = 1 + (3 / 4) * (og - 1)
Half and half:
    1st Run 1/2 = 1 + (4 / 3) * (og - 1)
    2nd Run 1/2 = 1 + (2 / 3) * (og - 1)
3 thirds:
    1st run 1/3 = og * 1.5
    2nd run 1/3 = og
    3rd run 1/3 = og / 2