IBU with Beersmith on high gravity beer

[Brewsterguy]

Hey guys,

I am going to brew a pliny the elder clone for the first time, using my own Extract version.
The fermenter vol is 13.7L and my top off will be 5.5L
the question is, is the IBU calculated by beersmith true? Can i really get to 100IBU's with only about 60g of hop providing most of my IBU's? it seems a bit far fetched to me, as 5.5L of top off is a lot.
Should I try and work with less top off to get more accurate? Can I even get to such high IBU with so much top off?

 

[dmtaylor]

In reality, you'll hit a ceiling of about 90 IBUs, and given that you are topping off, my guess is you'll end up with closer to 75 IBUs, something in that ballpark. If you want something in the 80-90 IBU range, top off less. Any calculator that puts out any number greater than 90 IBUs is... not realistic. Even if the IBUs were calculated to be 500 IBUs, you'll still end up with something around 80-90. The reason is that there is a physical limit to how much isoalpha acid can dissolve and remain in the beer following fermentation.

 

[Brewsterguy]

In reality, you'll hit a ceiling of about 90 IBUs, and given that you are topping off, my guess is you'll end up with closer to 75 IBUs, something in that ballpark. If you want something in the 80-90 IBU range, top off less. Any calculator that puts out any number greater than 90 IBUs is... not realistic. Even if the IBUs were calculated to be 500 IBUs, you'll still end up with something around 80-90. The reason is that there is a physical limit to how much isoalpha acid can dissolve and remain in the beer following fermentation.

I appreciate the reply!
I think I will try to do a 5.5l top off, and just use it as a base standard on this brew size. Those IBUs are as high as they get

 

[hottpeper13]

Since it's an extract why not make the main boil 1.050 ,use Palmers chart and formula at about 25% utilization,then add the rest of the extract and top off. You need to use your ending volume with all the additions. This way would get the most out of the hops.

 

[Brewsterguy]

Since it's an extract why not make the main boil 1.050 ,use Palmers chart and formula at about 25% utilization,then add the rest of the extract and top off. You need to use your ending volume with all the additions. This way would get the most out of the hops.

It's my 7th or 8th beer alltogether, so I dont quite understand you yet. any chance for a link or something that can help me study?

 

[BrewnWKopperKat]

@Brewsterguy : partial boil with late additions (water, extract) work well for normal strength beers.

Styles with high gravity and high IBUs likely won't work well with this approach because of the limits on the amount of IBUs that can be boiled into the wort before the late addition of water.

In your situation, a 13.7L batch with a 5.5 L top off suggests an 8L boil.

Assume a limit of 100 IBUs in each liter of wort. With an 8 liter boil and 100 IBUs per liter, there would be 800 "units-of-something" in the wort. When the additional 5.5 liters of water is added, those 800 "units-of-something" are spread across a larger volume of wort.

• 800 = 8 (liters) * 100 (IBUs)
• 800 / 13.5 (liters) = ~ 60 (IBUs)

Here's a chart to show estimated IBUs with other final batch sizes (and top-off amounts)

 

[Brewsterguy]

@Brewsterguy : partial boil with late additions (water, extract) work well for normal strength beers.

Styles with high gravity and high IBUs likely won't work well with this approach because of the limits on the amount of IBUs that can be boiled into the wort before the late addition of water.

In your situation, a 13.7L batch with a 5.5 L top off suggests an 8L boil.

Assume a limit of 100 IBUs in each liter of wort. With an 8 liter boil and 100 IBUs per liter, there would be 800 "units-of-something" in the wort. When the additional 5.5 liters of water is added, those 800 "units-of-something" are spread across a larger volume of wort.

• 800 = 8 (liters) * 100 (IBUs)
• 800 / 13.5 (liters) = ~ 60 (IBUs)

Here's a chart to show estimated IBUs with other final batch sizes (and top-off amounts)

View attachment 824019

Thank you. Can I go around the IBU problem by boiling for example, 5L of water with bittering hops, and freezing them?
I can then use them as the top off portion of my water.
Another approach is to go with less top off and doing basically a no chill. I can time my brewing to finish towards the night, "top off" with 2L of ice and pitching in the morning

 

[BrewnWKopperKat]

Can I go around the IBU problem by boiling for example, 5L of water with bittering hops, and freezing them?
I can then use them as the top off portion of my water.

One of the concerns around adding ice to wort is the possibility of contamination.

Another approach is to go with less top off and doing basically a no chill. I can time my brewing to finish towards the night, "top off" with 2L of ice and pitching in the morning

Using just two liters of top-up water vs 5.5 liters would result in 80 estimated IBUs, rather than 100.

And 80 estimated IBUs may be "close enough".

 

[Brewsterguy]

One of the concerns around adding ice to wort is the possibility of contamination.


Using just two liters of top-up water vs 5.5 liters would result in 80 estimated IBUs, rather than 100.

And 80 estimated IBUs may be "close enough".

Thanks. I think I will do that then. Use 2l of ice as top off just to lower temp faster.

I top off all of my batches with at least 8L of water that is usually 50% ice. Never had much issue.


Not saying there is no risk but for me it's the same risk as always.

 

[hottpeper13]

Just saying that the less the SG of the boiling wort the higher the hop utilization.(page 58 in Palmers book how to brew).