First Attempt at Parti-Gyle Brewing

I've been thinking about parti-gyle brewing for some time now; it may be the first time I've done it but it is an age old principle where a strong beer is made from the first runnings and then a small beer is made by adding some further grain (a process known as "capping the mash").


It meant a bit of juggling with my Beer Smith recipe software; I ended up doing three recipes, a double cornie length brew to get the right grain bill and then two 19 length brews to get the right levels of bitterness. The base was mainly Maris Otter with some aromatic malt, carapils and caramunich. The total grain bill came to 10kg, 1.5 of which was kept back to cap the mash.


The first beer ended up being a slightly less bitter version of Whispering Bob with T-58 yeast instead of the usual US-05. Of course it came out a bit stronger than I originally thought with an OG of 1072. If it ferments out as low as it usually does, that'll end up being around 8.5% abv.


Guessing that the small beer would mean fewer bittering hops would be required, I reduced the bittering hops, a Sorachi/Citra combo but was slightly surprised to find a pre boil gravity of 1034 turned into a post boil one of 1048.


The whole process took a couple of hours longer than a normal brew, although having a separate HLT and a 10 gallon boiler and mash tun certainly helped, It is certainly something I'll be doing again.


Grain Schedule


8260g Maris Otter Pale Malt
620g Aromatic Malt
620g Cara-Pils
550g Caramunich


Total grist weight 10050g


Hold back 15% for small beer, 1500g.


Strong Beer - Hop Schedule


31g Centennial 10%AA (FWH, 90 mins)
27g Amarillo 8.5%AA (FWH, 90 mins)


9g Simcoe 13%AA (Boil 30 mins)
9g Cascade 7.6%AA (Boil 30 mins)


22.5g Simcoe (Flame out)
22.5g Cascade (Flame out)


Yeast Safbrew T-58
Protofloc 5 mins from end of boil.


OG 1072
Estimated ABV 8.5%
Estimated IBU 74


Small Beer - Hop Schedule


18g Citra 13.8%AA (FWH, 60 mins)
18g Sorachi 12.2%AA (FWH, 60 mins)


10g Citra (30 min)
10g Sorachi (30 min)


25g Citra (Flame Out)
25g Sorachi (Flame Out)


Yeast US-05
Protofloc tablet 5 mins from end of boil.


OG 1048
Estimated ABV 5.5%
Estimated IBU 74