So, my last post was an introduction into the PGM (Parti-Gyle Method) and what it is, how it works etc etc…
This post is an explanation of my research and what I’ve got planned for the first PGM batch I’m planning on doing.
So, the first thing I found is, its really difficult to plan with any level of accuracy what your PGM brews are going to look like both in terms of SG and Colour given the difference between the sugar levels and colour of the gyles. I decided to use the information I had from the Randy Mosher table available here, and the various other bits available in books and other websites (most of which only confirms what is in that table) to create a rough guide spreadsheet to be able to estimate the colour and the FG, this is available here.
The spreadsheet kinda works in conjunction with beersmith or whatever brewing software you want to give you a more, well, accurate isnt quite the correct word, likely might be better here, idea of how your gyles will turn out.
I put the initial batch together with the grain to get to a gravity and a colour, forget yeast and hops for the minute, they dont affect the initial gyling (No idea if thats even a word, but we’ll go with it for now) and that gives me a recipe for the grain as seen below.
I use this to add the values into the spreadsheet to see what the 2 gyles will look like and to give me a slightly less guessed view of the starting point in terms of colour/gravity for the hopping and what yeasts I might wanna use. This looks like this…
So from this spreadsheet, based on the ideas from the Mosher Table, I know with the boil off rates of my 2 kettles and the colour, grain bill, mash thickness and total batch OG that i’m going to end up with 2 gyles of the following ilk.
Once I have the 2 gyle values, I create recipes in BS with the appropiate gravities and colours (colour adjustment for the purpose of the starting point here is done using crystal 60, which I wouldnt use in a lager) then any grains which I’m adding specifically to change colour, add body etc for the second gyle added to the second gyles recipe.
The advantage of doing it this way means you have an easier way to adjust your hopping and if required, DME additions for the batches easily depending on the wort gravities. If I screw the efficiency and end up with a lower gravity for the first batch I want to be able to adjust easily on the fly rather than having to sit down a redesign the whole fucking shebang. It took me long enough to get to this point, I have no desire to have to do it all again under pressure and during a brewday which is going to be hectic enough.
So, this is my starting point, and I haven’t had chance to do this since I’ve been dying on my arse for the last 10 days with some form of lurgy and leg-aids caused by some biting little insect.
Its a complex way to do a brew day, but once you’ve got your head around the way parti-gyling works its quite easy to plan it. As they old saying goes, the proof of the beer is in the drinking, so I’m reserving judgement on the application of the method until the beers are done and ready to drink, but the equipment is in place and the understanding is getting there. Just need to calibrate the old refractometer and I’ll be good to give this a shot, I wouldnt want to be using a hydrometer for this one, the volumes are quite small with this batch so a drop will be better than 100mL when it comes to checking.
Hope you’ll all stick with me and live the PGM journey vicariously through my posting and I hope I can encourage some of you to give it a shot. The spreadsheet should be downloadable, so feel free to take it and use it if you want.