Hops in concentrated wort

[Bierman707]

Is there any reason that a batch of beer wouldn't turn out okay if you're boiling 3 gallons of wort then adding two gallons of cold water to get your cold break, when concerning hop addition? The 3 gallons would be concentrated considerably.

 

[Ozarks Mountain Brewery]

I do that with my extracts in my 5 gallon pot it's fine, but you need to account for the hops in a 5 gallon batch not a 3 if that's your top off level, but it works to cool fine as a matter of fact I freeze the water days ahead then poor the wort on top, it melts the ice and cools the beer

 

[J A]

The concentration of sugars in the wort have a big effect on the hop uptake. Use the calculator to lay out the recipe and it'll tell you what your IBUs are doing. Depending on boil length you have to change hop amounts or addition times to manage the bitterness, etc.

 

[Bierman707]

I do that with my extracts in my 5 gallon pot it's fine, but you need to account for the hops in a 5 gallon batch not a 3 if that's your top off level, but it works to cool fine as a matter of fact I freeze the water days ahead then poor the wort on top, it melts the ice and cools the beer

Okay, great!! I was watching a guy on YouTube and he was making a point on an all grain batch. He had to split his wort into two kettles because he didnt have enough room. Anyway, he didnt want to add the hops to the more concentrated wort for some reason or another. I couldn't figure out why he was naking a point of it.

 

[Ozarks Mountain Brewery]

so since the wort is concentrated the hops will be too, treat the beer as a 5 gallon batch and add hops just like you would in a 10 gallon pot, after you do this you might need to add more hops than normal the next time because the extra water will dilute the bittering hop since it wasn't boiled

 

[White Haus Brews]

It's been found that you'll get less hop utilization/lower IBU when you're adding them to a concentrated wort which is probably why they made a big point of it. You may find you need a larger amount of hops to achice the same bitterness. You can find out what that is by changing your batch size to 3 gallons in brewers friend and adjust the hops accordingly to get your pre diluted IBUs right.

 

[Yooper]

It's not so much the concentration of the wort- it's the dilution factor.

What I mean is this- the maximum amount of hops oils that can be isomerized before the wort is saturated is less than 100 IBUs. It is most likely around 80 IBUs in a perfect setting (with a non-concentrated wort). That's fine for most beers, and you can boil 2.5 gallons and top up with 2.5 gallons in many cases.

But think of the IBUs and what happens, if making a highly hopped/bitter beer. Say you manage to get 100 IBUs in that 2.5 gallons of wort. That's unlikely, but it makes the math easier. So you have 2.5 gallons of 100 IBUs wort, and 2.5 gallons of 0 IBU water. That means, at most, you'd have 50 IBUs in the beer. In the real world, you might get 80-85 IBUs, so you'd get 40-42 IBUs in the wort.

For most beers, that's more than adequate.

It is not ideal for IPAs and higher IBUs beers though. In those cases, something like HopShot or one of those concentrated hops oils would be more likely to be needed to be added to increase the IBUs.

When I did stove top brewing, and was limited to boiling about 4-5 gallons, I would split it into two pots when I made an IPA.

 

[Nosybear]

Yooper is right: An IBU is a mg of alpha acid per liter of beer. You dilute the beer, you reduce the IBUs. It's a straight proportion.

 

[White Haus Brews]

@Yooper - Thanks for taking the time to explain it in more detail, that makes sense. Just one follow up question - if the lower IBUs in a partial boil beer is all due to dilution why did you add the caveat that the perfect situation for getting the highest IBU saturation would be in unconcentrated wort? Or were you just pointing out that although wort concentration is a factor, the bigger limiting factor would be the alpha acid saturation and then dilution?

Sorry if that's nitpicky, I just like to have a better understanding of of what's going on

 

[Nosybear]

@Yooper - Thanks for taking the time to explain it in more detail, that makes sense. Just one follow up question - if the lower IBUs in a partial boil beer is all due to dilution why did you add the caveat that the perfect situation for getting the highest IBU saturation would be in unconcentrated wort? Or were you just pointing out that although wort concentration is a factor, the bigger limiting factor would be the alpha acid saturation and then dilution?

Sorry if that's nitpicky, I just like to have a better understanding of of what's going on

What she's saying is wort can only dissolve so much alpha acid. The amount it can dissolve goes down as the concentration goes up. It follows then that you can get higher IBUs, mg/l of iso alpha acid in wort, if the wort gravity, the concentration of sugars in it, is lower. So yes, the highest saturation of alpha acids in wort is in the least concentrated worts.

If you brew, then dilute, the limiting factor of the absolute amount of alpha acid is the IBUs times the volume in liters (mg/l * l). You can't get any more than your initial amount of alpha acid. When you dilute, your IBUs (mg/l) become the mg of alpha acid divided by the number of liters of wort. Since you've diluted, your volume is higher; therefore, your IBUs are lower. So yes, the limiting factor is the concentration of alpha acid - what IBUs really measure - and the dilution factor.

 

[Yooper]

Yep- while the boil gravity isn't as important as was previously thought, there is still an impact with the solubility and the isomerization of hops oils. It's not huge, but even 15 IBUs lower in a higher concentrated wort means quite a bit when then later diluted besides.

 

[White Haus Brews]

Got it! Thanks for clarifying