Interesting experiment with frozen, unboiled wort.

[dundas68]

So, back on June 12 a friend and I tried to brew a larger batch than what we normally do. We are set up to do 3 gallons, but were determined to brew a 5 gallon batch. Well my mash tun, which is a 5 gallon circular Coleman cooler, couldn't handle the amount of grain and we had a very stuck sparge. We eventually got roughly 3.5 gallons out after about 2 hours,

so we decided to start boiling. We then carried on as usual and finished the brew. However, there was still about 1.5-2 gallons in the mash tun, so we decided to strain it into a separate pot and figure out something to do with it later. So we stuck it in the freezer where it sat until today. Not long after fermentation began we decided that we should take it out of the freezer, carve off the grain that had frozen at the bottom, boil it and add it to the original batch. Our intentions were to do this while fermentation was still active, but it took a while longer than that to get around to it.

So today I took the frozen pot out, sat it in a sink full of hot water so that it would slide out, and carved off the grain which had frozen on the bottom. I then placed it in 1 gallon of boiling water and brought it up to a boil and left it there for 30 minutes. After this I chilled it in an ice bath, siphoned it into the original batch and sprinkled some S-05 dry yeast onto it again. Adding the extra yeast seemed like a good idea because primary fermentation had pretty much stopped and I figured it would help deal with this extra wort. I'll give some of the specifics of the recipe below, but basically I was wondering if anyone has an idea of what might happen, or if anyone has ever used frozen wort in the past and if so what for? The gravity of my unthawed wort was 1.021, btw.

Recipe:

Grain
6 lb 2 row
3 lb Maris Otter Pale
1/2 lb Crystal 40
1 lb Flaked rice
1/4 lb Flaked barley

Hops:
1/2 oz East Kent Goldings (60 min) 4%AA
1/2 oz East Kent Golding (10 mind) 4%AA
Total of 9.6 IBUs (from Brewgr)

Pre Boil G: 1.070
OG: 1.039 (of the original batch, not the frozen wort)

 

[masonsjax]

I freeze wort for starters.

Adding it to an existing batch will give you more beer. Unboiled may give you an unwanted infection though.

 

[johngaltsmotor]

Well as a partial boil originally your hop utilization will be low so your IBUs will end up lower than predicted. But otherwise it should be fine. Boiling the leftover wort killed any funk (in reality you didn't need 30minutes). So you diluted the frozen by boiling it in water or like a double boiler surrounded by water? Either way it's okay, just you added extra water and diluted the final gravity and flavor if you added a gallon of water.
In the end: it will be beer. Drink it and be happy Then next time use what you have learned and plan ahead.

 

[dundas68]

Well as a partial boil originally your hop utilization will be low so your IBUs will end up lower than predicted. But otherwise it should be fine. Boiling the leftover wort killed any funk (in reality you didn't need 30minutes). So you diluted the frozen by boiling it in water or like a double boiler surrounded by water? Either way it's okay, just you added extra water and diluted the final gravity and flavor if you added a gallon of water.
In the end: it will be beer. Drink it and be happy Then next time use what you have learned and plan ahead.

Yeah I diluted it with 1 gallon of boiling water, but I'm not too concerned about it, we were going for something easy drinking anyways. I'll need a larger mash tun if I want to get up to 5 gallon batches, but I'm content with 3's for now. Thanks for the input!

What are your thoughts on the extra yeast? Will this be a sort of "secondary fermentation"? I left it in the same vessel, but the primary was essentially done, so i guess a second fermentation assuming this starts back up. I think I'll give it another couple of weeks then bottle.

 

[Foosier]

you didn't need the extra yeast as the yeast in the fermenter would have eaten up the new sugars. Adding the extra yeast won't hurt anything though.

 

[johngaltsmotor]

That was only 2 weeks ago so the yeast should have still be alive, just dormant from running out of food. You likely could have simply added the new wort and shaken to wake them up again. It shouldn't hurt though. You could do partial mash to make 5gal batches - make the 5gal of wort that you can and then supplement by adding water and DME/LME.

 

[peterj]

Maybe I'm not quite following, but it sounds like you added a gallon of water and 1.5-2 gallons of 1.021 unhopped wort to 5 gallons of 1.039 beer? If that's the case then you would probably end up with 8 gallons of ~1.029 beer that will have a very diluted hop character. Maybe you didn't top up after the boil though and added this in later to get it to 5 gallons total? That would be better, but you would still probably be light on the hops.

As for the extra yeast, it probably wasn't really necessary since there was plenty of yeast still in there, but it won't hurt anything.

 

[dundas68]

The original batch was intended to be 5 gallons, but with the stuck/really slow sparge we got 3ish, then I topped up with what we were unable/too impatient to get out of the mash tun (frozen stuff) a couple weeks later.