Software and boil, Ibu question. 2.5 gallon batches

[spark]

First of all, hello! I brew 2.5 gal batches. Have always steeped speciality grains in 2-3 quarts as it was suggested to keep ph down and reduce tannins. Ok - then I add that thin wort to boil pot making total of 1.25 gal water for my boil. Then add 8 oz dme to add some sugars for the hops. Now this may sound crazy, but I want to do no longer than 30 minute boil! Obviously Having to add more hops this way, it's how I need to do it though. After hops boil I add my LME in pot to sit and pasteurize about 15 minutes then cool, add to fermentor then top to 2.5 gallons with bottled cool spring water, pitch yeast. Please take a look at the screenshot from software I'm trying now with simple stout recipe. Does this look correct on my hops IBU and Potential ABV? That is my main concern. Also note that I listed 2.5 gal in pre boil box rather than my 1.25 gallon on a suggestion, should I change that? Thanks!

Btw... not a new brewer, new to the software. and it's been a while. Electric brew pots? Wow!

 

[ReaperOnefour]

you dont need to do all that homie. I brew 2.5 gallon extract batches too. I boil for 45 mins, but you can boil for 30 mins if you want. Your beer will just come out a little lighter. I start out with 2 gallons of water. ( you dont need to worry about ph levels if your doing extract.) If your tap water is a little to harsh, you can use a couple gallons of spring water from the store. My tap water is good so i fill up my kettle with two gallons of hot tap water, then steep for 20 minutes. I then bring the wort up to a boil, turn off the stove, add extract, stir well, bring to a boil, add first hop addition, & start timer. A 45 min boil usually brings me to a gallon & a half at flame out. I then add 5oz of dextrose after i add hops at flame out(if any). I then add one gallon of cold water to the kettle, & do an ice bath. I put the ice in the sink(with no water) Put the kettle on top of the ice pile & stir. In about 20 mins i am usually down to pitching temp. I usually pitch around 68-69 degrees, because when fermentation starts its going to kick up to about 72-73 degrees. ( depending on your ambient temp) I usually end up with a 6.2-6.4 ABV. Try this approach brother, let me know how it turns out.

 

[spark]

Thanks for reply I appreciate all help! Wondering if anyone can answer my questions about the software values i have attached as screenshot?

Yeah not sure why i wrote ph levels, i think using a pound or less grain for steeps it doesn't matter so much. But after much reading a while back I have always steeped my specialty grains in about 2-3 quarts water, reason is several articles including one at beer smith.com states: "When steeping grains for an extract brew, use no more than 1 gallon of water per pound of grain (8 liters/kg)". Many others sites say 2 quarts per pound. Reason being more water can add off flavors from grain husks... astringency. Probably not a big deal but i prefer steeping this way as it's always worked great.

Also i do not want to boil my lme but my main concerns are fairly accurate abv and ibu. looking at my software screenshot, it shows very different values then stand along calculators I've used lately. Example... one calculator shows 17.89 ibu while the software shows 39. ibu or so! So, do i need to change my pre boil amounts back to 1.25 gallons?

Due to situations i really need to boil no more than 1.25 gallons for 30 minutes adding lme and maltodextrine as late additions. I would really like to use this software for brewing since I've done many recipes with it already. Need to know if it's giving pretty accurate calculations with the values I've set. Lastly, even if i set values to add lme duing boil, ibu changes very little.

 

[BrewnWKopperKat]

one calculator shows 17.89 ibu while the software shows 39. ibu or so! ... So, do i need to change my pre boil amounts back to 1.25 gallons?

2.5 gal is your batch size. 1.25 gal is your 'end of boil' volume. Your 'start of boil' volume will depend on your boil off volume.

but my main concerns are fairly accurate abv and ibu

Cool down rate has a measurable impact on the number of lab measured IBUs:
https://www.experimentalbrew.com/experiments/writeups/ibu-lie-kind

Due to situations i really need to boil no more than 1.25 gallons

Zymurgy July/Aug 2019 has an short article by @Steveruch that may be of interest.

 

[RM-MN]

"When steeping grains for an extract brew, use no more than 1 gallon of water per pound of grain (8 liters/kg)". Many others sites say 2 quarts per pound. Reason being more water can add off flavors from grain husks... astringency.

To extract the tannins that give you astringency requires two factors to be met. The pH needs to be over 6.0 and the temperature needs to be over 170. It's pretty easy to avoid getting both conditions met, just keep the temperature below 170 when steeping.

The software attempts to predict the IBU's but it is imperfect. So is your tongue at determining just how many IBU's the beer has. I only boil my hops for 30 or 45 minutes and can't notice any difference between those two temperatures or from when I boiled for 60 minutes. I've read that 90% of the bittering happens in the first 30 minutes and that seems to fit my experience too. Unless you are very good at determining the IBU's in a beer, I'd suggest you just take the software's estimation for a 60 minute boil and use that value for your 30 minute boil.

 

[dmtaylor]

Is this just a repeat/reworded version of this thread where some of us already answered? Even if not, you'll find the information useful:

https://www.homebrewersassociation.org/forum/index.php?topic=34112.msg432191#msg432191

I think the 36 IBU calculation is way off. By my own calculations, which emulate Tinseth but include hop-stand corrections, I expect you'll get closer to 28 IBUs. Is the software using Tinseth? How does it account for the ~15 minute stand between end of boil and cooling?

ABV will be highly dependent on the particular recipe and yeast strain used. You mention maltodextrin -- how have you accounted for this non-fermentable? Personally I would not recommend adding maltodextrin until ready to bottle or keg, if needed for extra body, since it is a body agent and not fermentable. This stuff can also throw off your gravity and ABV calculations. Also I really would like to know what yeast you will be using, that's essential. The ABV calculation looks reasonable... but need more info to verify.

 

[spark]

Thanks for ALL of the tips guys, had not thought of those things! will give it all a try. I believe i've concluded that none of the software out there is set up to do recipes very accurately with 2.5 gallon batches, especially with the methods i want to try. tricky on ibu's since i want to try the grain steep, then only 8 oz dme in boil for hopping method! lme being late addition. oh well, back to work! cheers!

 

[BrewnWKopperKat]

none of the software out there is set up to do recipes very accurately with 2.5 gallon batches

Assuming the brewing process is "Boil Hops, not Wort" from BYO (Oct 2002, follow @dmtaylor 's reply (above) to a link for the full process), you should be able to use recipe software with this process. You may need to adjust a "configuration" switch (or two) or "dial in" a input box (or two) to improve the accuracy of the estimates.

The "Boil Hops, not Wort" process appears to be a 60 minute, full volume (5 gal)boil with a massive (100%) late addition of malt extract. Shortening the boil time to 30 minutes is common. Scaling recipes down to a 2.5 gal batch size is common. Revising a recipe to be a "partial boil" (1.25 boil, 2.5 gal batch) is also common. The ABV calculations should be really close, SRM (color) calculations may be off due to using 'older' LME, and accuracy of IBU estimates is covered well elsewhere.

At the moment, this article (while over 10 years old), is still an excellent article for those who are interested getting lighter colors using malt extract (but using DME): http://menuinprogress.com/2007/08/on-importance-of-late-extract-addition.html.

Another approach would be to use various 'no-boil' (be sure to pasteurize) techniques that were discussed in HBT early in 2019. Basic Brewing Radio (Nov 1, 2018) has some initial experimental data which could be used to build a model to estimate IBUs.

 

[Oginme]

Thanks for ALL of the tips guys, had not thought of those things! will give it all a try. I believe i've concluded that none of the software out there is set up to do recipes very accurately with 2.5 gallon batches, especially with the methods i want to try. tricky on ibu's since i want to try the grain steep, then only 8 oz dme in boil for hopping method! lme being late addition. oh well, back to work! cheers!

With any of the software currently available, the user must customize the process configuration: equipment, boil off rate, efficiency, water additions, etc., in order for the software to give a reasonable answer. Sometimes it takes a bit of trial and error with a recipe having a known result to get the software to spit out the results which will match yours.