Frozen wort and most likely to infection temperature

[juagula]

Good morning all,

I am planning to freeze some high gravity wort made out of DME (10% of the total boil volume) and add it into the hot wort during chilling. I have one question about it:

What is the temperature at which the wort is most likely to get infected during chilling? I will add the frozen blocks at that temperature, and that will cool down around 10-15 Celsius very fast (for example, from 167F to 145F). My chiller is crap, I need to speed this up, at least at the most delicate moments.

Another good point is that I will be able to regulate my OG. As I BIAB, I am not reaching the OG. By having added this high density wort, I will increase gravity closer to OG.

Thanks!

EDIT: Check results/impressions below

 

[daksin]

Good morning all,

I am planning to freeze some high gravity wort made out of DME (10% of the total boil volume) and add it into the hot wort during chilling. I have one question about it:

What is the temperature at which the wort is most likely to get infected during chilling? I will add the frozen blocks at that temperature, and that will cool down around 10-15 Celsius very fast (for example, from 167F to 145F). My chiller is crap, I need to speed this up, at least at the most delicate moments.

Another good point is that I will be able to regulate my OG. As I BIAB, I am not reaching the OG. By having added this high density wort, I will increase gravity closer to OG.

Thanks!

I think you'd be better off boiling a higher gravity wort and then "topping off" with ice. Less chance something that likes to grow in beer will get into ice than cooling wort blocks. This will also make it much easier to predict your gravities.

 

[ArkotRamathorn]

The time it takes to drop the high OG wort to the point of freezing would leave it in a danger zone for awhile. Usually the danger zone is mitigated in a normal beer situation by pitching yeast, the yeast start making the sex and make the beer an unfriendly place for other types of bugs to exist.

Depending on how it freezes and the vessel you freeze it in, you might get less accuracy than you would expect. I just iced 5 gallons of a beer and when it melted it seems to melt in a specific manner. A column in the middle of the 5 gallon jug, the bottom of the jug, and the sides all melted first, there was a cup shaped chunk of water ice inverted inside of the jug stayed frozen the longest. So depending on the vessel you freeze it in, or if you freeze it all at once and take chunks out you may end up taking a piece from a water ice area, or a high sugar ice area.

It is a clever idea in general, though over engineered. If you happen to have a commercial grade blast freezer, can pour liquid nitrogen all over the wort (and store it in a really cold deep freeze), or pastuerize in a completely sealed container than can also take the stress of expanding water thats freezing, it could work.

 

[juagula]

Thanks for the replies!

The idea is to cool down the wort to room temperature and freeze it in sanitized boxes no bigger than 0.5L (around 2 cups). Then I can choose the amount of boxes depending on the OG I reach. If I reach the correct one I can also add one box of frozen wort, one of ice. As I will add full boxes I dont need to worry about having the middle different, everything will just go in and mix. I dont happen to have a commercial grade blast freezer.

 

[Riot]

Wouldn't it be easier to just upgrade your chiller? Got a blowtorch and 60 bucks to spend?

 

[juagula]

Wouldn't it be easier to just upgrade your chiller? Got a blowtorch and 60 bucks to spend?

In Norway? No way! EVERYTHING is expensive as fck here.

Brewday Thursday, I'll let you know the results.

 

[ArkotRamathorn]

In Norway? No way! EVERYTHING is expensive as fck here.

Brewday Thursday, I'll let you know the results.

With the pictures of your guy's winters in Norway, I'm surprised it doesn't freeze right in the kettle mid boil.

 

[juagula]

Hello!

I brewed yesterday night. Some thoughts about this system:

As @ArkotRamathorn said, it melts in a specific way: the bottom middle of the ice box has much higher density. I didn't think that would be a problem, because at the end everything would mix. BUT that very high density part had big trouble melting. I still had some solid at the end of the cooling. I assume I can fix that adding the block earlier. This time I wanted to speed up from 130F, which is what creates more problems with my crappy chiller. If I add it at 190F it should improve. This is a problem because the big contribution to the cooling should be done by the melting process, so if it doesn't melt, it doesn't speed up as much as possible. It is also a problem because I don't get the right density at the beginning, so it is difficult to measure and add water if needed.

Good thing: It really boosted the cooldown taking from 130F to 110F in around 10min (total cooldown was around 45min, most of them after 110F).

So, for next time I will do what was suggested by @daksin and use normal ice from previously boiled water and add DME to the wort during boiling if needed to adjust. I will also benefit from the cold as sht norwegian winter by leaving a big bucket full of water in the backyard the night before so I have a huge ice block to put my pot in

Just for reference, I lived some time in Wisconsin and it was colder than the populated part of Norway...