August 27, 2010

Partigyle Experiment: Take One

Ok, so as a quick recap, I brewed Swordfight several weeks ago. Considering how thick the grain bill was, I wanted to maximize the grain bill, so I ran about three gallons of extra sparge water through the grain bed after collecting what I needed for the actual beer. I froze this wort in sterilized freezer bags, with the intent of turning it into a partigyle Belgian blonde. Mmmmmmmmmmm!

I had trouble finding a sensible (and simple) walkthrough of how to make a partigyle, so I wanted to lay out the course of making this one, if for no other reason than to record the process for next time. So I’ll try to be very pictorial about this so it makes sense for me, as well as any readers out there trying to figure out how to do this.

History/What is a partigyle?

Old school brewing was different from modern brewing. Today, we mash, sparge, and mix all our runnings to get one full batch. In the past, different runnings from the mash were not aggregated into a single beer. The first runnings -- from the mash -- would become a high alcohol beer. Then another round of water would be sent through (think of a batch sparge) which would become a medium alcohol beer, and then a third round of water would similarly be passed through, which would become a "light" beer. This was more common when resources were more scarce or a small brewery lacked the resources to be wasteful with water or grain. Other partigyle techniques exist, such as using second or third runnings as mash water for a new batch to build up the strength of the beer.

As a homebrewer, I always look to maximize efficiency and value in my brewing, so long as I produce products I'm happy with. That means I'll do a decoction mash or infusion mash when I could have done a single infusion mash if it means producing a better beer, but I'll also hand-build equipment, wash yeast, buy hops in bulk, etc. There's definitely a balance there, I won't try to minimize cost to the point that I'm getting so much efficiency I'm wasting time trying to do it. To that end, I like the idea of maximizing the value of grains on a big beer by making a partigyle, but I wouldn't do it for regular brews because I'd spend a lot of time brewing tiny batches of partigyles and the time cost would significantly outweigh the financial gains from the extra beer. Besides, I generally try to sparge a little extra to make extra wort for future starters. Ok, enough rambling. On to the brewing!

Creating the goal

Step one is always to figure out what you want. I knew I wanted a Belgian blonde, and since Swordfight is a golden strong ale, a blonde is roughly a weaker version of this beer. I want the beer to be low on IBUs, similar to Leffe, so I’ll target a lowly 18. I plan on using my seemingly endless supply of Fuggles, since English hops are style appropriate and I don’t have to buy anything extra for this beer. The alcohol will be around 4-5%.

Since I have three gallons of what I guess to be very weak wort, I will need to melt it down, take a gravity reading, and see where the gravity is. My goal is 1.035 pre-boil. I calculated this by taking a rough approximation based on rebuilding the recipe based on half the grain (see picture below). It's not an exact science -- I'm sure people with greater experience with partigyles can make it exact -- but the gravity readings will offer that exactness and I'll figure out the volume of wort and restructure the partigyle recipe from there.

I’m more concerned with making a good beer than a lot of beer, so although my goal will be to walk away with a 2-2.5 gallons, I’m comfortable getting a lot less. Fortunately with making a blonde, I have the luxury of being able to add a decent amount of sugar to the boil to increase the OG, so I can have a fairly low pre-boil OG and know the sugar is going to kick it up a bit. If my pre-boil gravity is too high, then I get to add water and increase the amount of beer. I may end up getting too high of an OG after the boil, in which case I will just add top off water.

Starting the process

I’ve taken the original recipe in beersmith and cut the grain bill in half to get a rough idea of what I’m working with. I’ve used this to add the hops and sugar to approximate the IBUs and ABV I’m shooting for. It shows 1.042 as the pre-boil gravity goal, but I adjusted it to 1.035 after I took the pic. So far this does not include the table sugar addition, which gets the ABV up to 5.23.

And here is the wort thawing in the kettle:

As you can kind of see from this terrible picture, the current pre-boil OG is 1.01. That's too low. At this point, I am retooling the recipe to aim for a lower ABV, in line with what is more common for partigyles.

So I've lowered the ABV to 4.69 and the pre-boil OG to 1.030. To get there, I'll need to boil the wort to concentrate it. That's going to reduce the overall volume of beer, but hey that's the price you pay to have something more than 3% ABV.

Boiling boiling boiling...

And boiling boiling boiling...

This part is a lengthy process since you have to heat up wort, take it off the heat, take a sample, cool it, then check the gravity, and repeat until you hit the desired gravity. The reason why I am taking it off the heat is that if I have hit the right gravity I don't want to continue to concentrate the wort while the sample cools.

After seeing how much I will have to concentrate, I'm having second thoughts. I've again lowered my pre-boil gravity to 1.017 which with the addition of sugar will get me to 3%. A light beer for sure! I've reduced the batch size to account for what I believe will be the ultimate size (2 gallons) and reduced the grain bill appropriately to change the OG to 1.022 before sugar, which by my very rough estimate gives me a pre-boil OG of 1.017. Once the boil is done I'll take a sample, figure out the actual OG and then top off if necessary.

Once I hit the right pre-boil gravity, it's time to start the boil and get all the additions going. As the boil progresses and boil off occurs, the batch is quickly getting very small. It's about 45 minutes into the 90 minute boil and the batch is about 1.5 gallons (by my guess). I guess we'll see how that looks once it cools. A really important lesson I'm learning is that you should partigyle huge beers because you're going to boil down anything else for a long time to get down to a worthwhile ABV. My three gallons are quickly diminishing...

So by the end of the boil I had somewhere around 0.5-0.75 gallons. However, an OG reading shows a whopping 1.085. Too high! (The picture shows it at about 1.078 but it's still warm so when temperature adjusted it corrects to 1.085.) I'd rather have more beer than a couple bottles of stronger beer. So I'll boil up some water and add it into the wort to get down to my now preferred 1.030 OG beer.

Ultimately I added a little over a gallon of water to get down to 1.032, so I ended up with about two gallons, as I desired. Now that it's all done, off to the fermenter it goes and I'll bottle next weekend so I can use the cake to make a fake kriek lambic.


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