Parti-Gyle Saving last runnings

[keppybrau]

So, I was reading up on parti-gyle brewing and I thought after making a big IPA that I could run another couple gallons out of my mash tun and set it aside. My plan was to do this after a few beers and save up enough for a bigger batch, and add some extract to it and make a regular beer or top off another beer to get more volume.
The first time I did this, I put one gallon in an old plastic water jug. After a couple weeks, I noticed the jug had swelled up, and when I cracked the top, it had some pressure on it. So, obviously natural yeast had gotten into it and fermented it. So, I tossed it.
Two weeks ago, I did the same thing, except this time, I put 2 gallons into a 2.5 gallon carboy and topped it with an bung and airlock. I didn't pay attention to it to look for bubbles or anything, and I did not measure it's original gravity. But it looks to have sediment on the bottom, and some stuff on top. I will post pictures.
So, I have a few questions. Has anybody done this? What steps can I take to avoid this from happening again? If natural yeast still got in with my airlock on, how much natural yeast is getting in my normal beers?
thanks.

 

[SlowBoy]

Do you boil the wort collected prior to storing? The mash is not a sanitary environment and the runnings will not store well if they have not been boiled for a short time.

 

[yorkbrewer]

Yup you should probably boil to sterilise. But I know that is a lot of bother for last runnings - especially when your brew kettle is obviously in use, boiling the good wort.

Are you pitching your own yeast into these last runnings?

You could just pitch some as soon as it is cool enough, then keep adding last runnings - and maybe more yeast - to it each time you do a brew until you have 5 gallons or so. You would probably end up with some god-awful phenolic, hazy, weak pisswater.

But the good news is that all you then have to do is serve it cool and get Jean-Claude van Damme to advertise it.

 

[keppybrau]

Do you boil the wort collected prior to storing? The mash is not a sanitary environment and the runnings will not store well if they have not been boiled for a short time.

No. I did not boil it before storing. Duh. That makes sense.
How long? 15 minutes?
I had planned on boiling it when I had enough collected to make another batch. Could I then boil it again when I do get enough collected?

I didn't add yeast to it. Like I said, I planned on adding extract to it and making a sort of partial mash. Or, I was thinking I could boil it before I do another batch, then add it to add volume to another beer instead of adding distilled water.

My main thought here is to not be wasteful. I'm making a 1.080 Double IPA this weekend, and by parti-gyle theory, after I'm done with the wort collection for that beer, those runnings should be around 1.040. So, that's pretty close to a normal beer. I feel it's wasteful to just throw that away.

 

[SlowBoy]

15 minutes should be fine. I don't believe you will have the same problem if you boil the "extra wort" prior to storage and it should be fine when you boil again to use it. I think it is difficult to get a vessel 100% sterile but it probably depends on your methods.

I may be at an advantage as I have access to multiple burners and kettles so I just brew both beers in one day. There is a whole other can of worms that could be opened up here regarding adjusting your initial recipe to correspond to your second and adding grains to the mash prior to sparging your second beer but it depends on how much time you can put into your brew day.

Try stirring some specialty/ base grains into your mash after you have collected your first wort and allow to rest 15 minutes with some strike temp water, this should get your second beer OG up where you want it if you are crafty.

 

[Zepth]

I've taking a liking to making a parti gyle batch from almost anything I make these days. Last couple batches the first was 1.056 OG and the second 1.044. Second batch is smaller volume, otherwise would have wound up in the 1.032 range. This is fine, it's virtually free. It makes for a longer day, but it isn't terrible and prevents the need for semi-long wort storage. Another advantage is that if you decide you really like the way a parti gyle batch worked out you have a good chance of replicating it. Taking the second runnings from 2-3 batches mixing them, fermenting it, and then deciding you want to clone that particular batch is likely going to be a nightmare.

 

[SeeMont]

With the couple of parti gyle batches I've done, After the first runnings, i'll cap the mash with a few pounds of new malt and sparge, getting around 1.045 to 1.050 wort. I would have a hard time storing wort.

 

[copyright1997]

If you want to store wort, the proper way to do it is to either freeze it or sterilize it. To sterilize it, buy a pressure canning unit, e.g. something like this: http://www.walmart.com/ip/Presto-23-Qt-Pressure-Canner/2625289. I use this to can wort for starters, and also use it to sterilize water for washing yeast. With it, you can make shelf stable wort that will keep at least a year. The 23 qt unit will hold 7 of the quart mason jars on the bottom shelf.

 

[jro238]

If your sanitation is good, boiled wort will store for about 1 week without any growth if plated out (per Mike White at White Labs). After this it is all chance. Grain naturally has lactobacillus and a number of other goodies all over it so the mash is not at all sanitary.

I haven't ever tried it, but the advice on pressure canning sounds like it should definitely work.