Parti-Gyle Style Brewing - First Attempt.

[fakr]

Tried my hand yesterday at some old school parti-gyle brewing.  
Definition here:  (http://www.homebrewtalk.com/wiki/index.php/Parti-gyle)

I started with roughly 20lbs base grain, and 10lbs of specialty.  This recipe was a black IPA and would be the typical grain bill for one of my 12GAL batches of IPA.

I mashed in at a water to grain ratio of 1.6:1 and let sit for 60 mins.
I then mashed out, collecting roughly 6.5-7GAL of wort, with just enough sparge water to prevent the grain bed from going dry.  I kept sparge water at 158F to bring the 148 grain temp back up to 152-154.

After mashing out, I mashed back in, trying to hit a water to grain ration of 1.4:1 and let sit.

Meanwhile, I boiled the first mash out for 60 mins, adding the approriate hops etc.  Chilled and transferred 23L into a primary with an SG of 1.093

Mashed out the second mash, collecting roughly 6.5-7GAL of wort.  Knowing this was a lighter version, I used half the hop bill of the previous over the 60 minute boil.  Chilled and transferred 23L into another primary with an SG of 1.042.

So, the big question is....what was my grain efficiency?  I know there is a calculation to estimate the SG of both runnings, just not sure about how to calculate the overall efficiency.

If my rough calculations are correct, I'm going to have 6GAL strong beer @ ~9.5% and 6GAL light beer @ ~4%.

I could have removed a couple of litres of light wort and added a couple of litres of strong wort to it to bump it up to 5%, but I didn't want to mess with anything this time around.


So, looking at what I'm left with after 2 mash-ins on the same grain bill, I now see that I've been wasting a good deal of potiential beer by throwing away grain used for stronger beers, which is typically what I brew.  I think from now on, I'm going to parti-gyle when I make heavier beers...this way, I will make more efficient use of my grain, and have a weaker version of the strong style of beer that I can serve to guests or drink myself when I have things to do.

[Richard]

Ignoring that specialty and base have different parts-per-gallon (the number of points one lb of grain imparts to one gallon of liquor at 100% efficiency), the standard number for 2-row is 37ppg.

So 30lbs for 12 gallons would be (30/12) * 37 = 92.5 i.e. the whole batch at 100% would have been 1.0925

Since it's all linear you can split the difference on your numbers down the middle like so:

(1.093 + 1.042) / 2 = 1.0675

so 675/925 = 0.72972973, i.e. ~73% efficiency.

Bear in mind my assumption that your specialty malts would be 37ppg and that's almost certainly not the case... in fact I think they're all less than that if they're barley.

[fakr]

Hmmm, would have expected higher than 73%.   I suppose, techically I did use pretty much the same amount of water as I would have with a 12 GAL batch so maybe the efficiency wouldn't have gone up.

Here's what I used for specialty grain in case you wanted to know or are able to calculate efficiency a bit better.....I think you'll recognize the bill:

4lbs vienna
2lbs light munich
2lbs cara munich
1lb  cara foam
0.5 carafa 1 special
0.5 carafa 1 malt

[fakr]

I guess, at the end of the day, if my intent was to just make a 6GAL high gravity brew, it would be, in the interest of efficiency, benificial to mash out again for a second "lighter" 6GAL batch....

[Richard]

Yeah if you're not getting more wort then you can't really expect better efficiency.

Those specialties are largely base malts, so won't affect the eff% much.

[fakr]

I guess if I really wanted to hit top efficiency, I could have mashed in a third time, and used that wort to mash in the next batch, assuming the same grain bill...

Regardles, from now on, I'm going to parti-gyle when I brew a high gravity wort.  Hell, I got myself an extra 6GAL of 4%+brew that would have been thrown out in the grain.

[fakr]

Thought I'd update this thread in case anyone was following.

3rd day into fermentation using us-05 and I've already hit my fermentation expectations.

strong batch OG=1.093, currently 1.019  so approx ABV 9.8%

3 day old impressions:

Not a black IPA flavor, like the original grain bill was meant for.  Considerably more malty.  A slight chocolate tone.  The 1/2 pound of hops in this 6 GAL is only noticeable until swallowed, then disappears.  More hops required.  Alcohol taste subdued by maltiness.


Weaker Batch OG=1.40, currently 1.003 so approx ABV 5.1%

3 day old impression:

Surprising SG.  did not expect this to ferment out this low.  Expected a 4% max.  
Dry taste, very little maltiness.  Again, no resemblance to the original black IPA grain bill.  Same hops as the strong batch, but quantity cut in half.  Much hoppier than strong beer.  Tastes like a dryer style IPA.  Citrusy, refreshing.


I'm going to wait until day 5, then transfer both to secondary to clarify.  I'm going to dry hop both, 1OZ Palisade in the light, and at least 2OZ Palisade in the strong.  I'll let the light set 1 week, then keg and bottle.  I'm going to let the strong sit 2 weeks, then keg and bottle.

[JohnQ]

Well, you could tap a little off for Mash Occur...

[fakr]

yes, I guess I could, as long as I get the stuff kegged by next weekend...might be too soon though.