BeerBorg

bpgreen wrote:

RickBeer wrote:Again, I think this is being overthought.

Brew as you intend - setting the software for a 2.5 gallon batch with the ingredients you have. QBrew shows 25IBUs (with Cascade at 7.1% AA), and 4.1% ABV.

Pour a gallon of cold water in the BrewDemon. Add your wort. Top off to 2.5 gallons, pitch your yeast.

There is no reason to try and figure out what the 1 gallon of wort comes out to. Just do a 2.5 gallon batch in the software. It doesn't care when you add the water.

QBrew cares when you add the water. Or, maybe more correctly, it doesn't, so it miscalculates IBUs when you don't do a full volume boil with all of the malt for the full boil time.

If you want a better approximation of your IBUs, you need to use software that allows you to set your boil size and that lets you specify late extract addition if you do that. That's a big reason I started using Beersmith.

If you use an HME that has 20 IBUs, then add some lme, qbrew will tell you that the IBUs have dropped, but they haven't. In Beersmith, you could set the lme as a late extract addition and the IBUs won't change. The bu:gu ratio will drop, which means that the perceived bitterness is lower, but the IBUs do not change.

In this case, you're not doing a late extract addition, but you're also not doing a full volume boil. The gravity of the wort used for the boil affects the efficiency of the hop oil extraction.

Right. But my starting point is a recipe that specifies exactly what I'm doing - 2.5 gallons, steep, hop boil with LME (all added at start of boil). It gives the result I expect. Therefore, given that, one can take the recipe and ratchet ingredients down proportionally. If you're at 5% and want to be at 4% simply start by cutting things to 80% of what the recipe calls for, except the water.

I just took a 5 gallon recipe for Oatmeal Stout that is 7.1% ABV, and ratcheted everything down by 20%. Ended up at 5.7% ABV, IBU of 21 (vs 23 originally) and color of 45 (vs 50 originally). Close enough for government work.

RickBeer wrote:

bpgreen wrote:

RickBeer wrote:Again, I think this is being overthought.

Brew as you intend - setting the software for a 2.5 gallon batch with the ingredients you have. QBrew shows 25IBUs (with Cascade at 7.1% AA), and 4.1% ABV.

Pour a gallon of cold water in the BrewDemon. Add your wort. Top off to 2.5 gallons, pitch your yeast.

There is no reason to try and figure out what the 1 gallon of wort comes out to. Just do a 2.5 gallon batch in the software. It doesn't care when you add the water.

QBrew cares when you add the water. Or, maybe more correctly, it doesn't, so it miscalculates IBUs when you don't do a full volume boil with all of the malt for the full boil time.

If you want a better approximation of your IBUs, you need to use software that allows you to set your boil size and that lets you specify late extract addition if you do that. That's a big reason I started using Beersmith.

If you use an HME that has 20 IBUs, then add some lme, qbrew will tell you that the IBUs have dropped, but they haven't. In Beersmith, you could set the lme as a late extract addition and the IBUs won't change. The bu:gu ratio will drop, which means that the perceived bitterness is lower, but the IBUs do not change.

In this case, you're not doing a late extract addition, but you're also not doing a full volume boil. The gravity of the wort used for the boil affects the efficiency of the hop oil extraction.

Right. But my starting point is a recipe that specifies exactly what I'm doing - 2.5 gallons, steep, hop boil with LME (all added at start of boil). It gives the result I expect. Therefore, given that, one can take the recipe and ratchet ingredients down proportionally. If you're at 5% and want to be at 4% simply start by cutting things to 80% of what the recipe calls for, except the water.

I just took a 5 gallon recipe for Oatmeal Stout that is 7.1% ABV, and ratcheted everything down by 20%. Ended up at 5.7% ABV, IBU of 21 (vs 23 originally) and color of 45 (vs 50 originally). Close enough for government work.

If you are doing a full volume boil, which you apparently are, then yes, what you said.

If you are topping up or doing partial volume with late extract then no. What BPGreen said. And what I said in a post up above somewhere about how to adjust your bittering addition to account for the increased wort gravity during the boil. I explained how to make it work right to get the intended IBUs in QBrew even though QBrew sucks at knowing how to do late extract and/or top up. What matters as far as IBU extraction in such cases is not volume, but boil gravity. You have to trick QBrew into thinking your boil gravity is whatever it is going to actually *be* to figure out appropriate amount/timing of bittering additions (which if topping up and/or late extract is not the same as if you are doing a full volume boil with all the malt in it). If doing late extract addition, then do what I said but backwards (figure your recipe at full volume, note the IBUs, then remove some malt until your gravity = whatever the boil will be with less malt in it, then adjust the hops (in this cause using less) to match the IBUs you jotted down).

Hope that made sense. We are talking about apples and oranges here, a full volume boil is not the same as partial and/or top up and/or late extract. QBrew is too dumb to handle those things properly on it's own.

The thread went that way I think because we were talking about such a scenario, not a full volume boil.

Hey Gang, I popped open one of my Amarillo Lites last evening.What a treat,not overly anything. A little malt,a waft of hops,nice carb. A really nice lawnmower beer.I'm pleased with the recipe.Will brew this again. Thanx again for your abundant knowlege.

Thanks for the update.

Yeehaw you made beer. Now go out there and get that pipeline full

Actually,I'm sitting on 9 cases in the Ol' Pipeline.All assorted.I usually only imbibe on the weekends,so I put together different sixers for Friday,Saturday,and Sunday. I have an Amarillo hopped and a Citra hopped Saison going right now.They should be ready around the beginning of Football season.They should be "Sassy". Once it gets cooler here,I'll jump back on the BrewWagon,and get to brewing.Cheers.