water volume question re: PM

malkore said:

if you can do a full boil, stop doing partial mash and go all grain baby!

but yes, if you have need to stick to PM, you can indeed add the top off prior to reaching a boil...thus having a low gravity, full boil, normal hop utilization, then add your DME or LME at 15 minutes left so it doesn't darken the beer as much.

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riored4v said:

slowly getting there.

as you saw in my other thread i'm still working out some kinks and getting a feel for things. once i get more money and bit more room i'll finally go AG.


I think i like the idea of being able to do a full boil. This next time I'll finally test out my effeciency prior to adding top off. Then top off and do a full boil.

If I add to much top off, and happen to end up around 5.25 gallons after 60 minutes for whatever reason, i can continue to boil until i hit 5 gallons correct? i plan on starting to create my own recipes and will probably calculate for 5.25 gallons to compensate for trub, but i ask about the 5 gallon mark since it seems most kits are calculated off of 5 gallons. Is there any downside to boiling an extra 30 minutes or whatever to remove that excess water?

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YooperBrew said:

Well, a couple of things I see here- one is that you should top off and THEN check your efficiency. Then you'll know how much DME or LME you'll need to add to get you to the correct OG. Top off and let it boil for a minute or so, pull your sample and cool it. If you're lower than expected, or higher, you can adjust the amount of DME. If you have brewing software this is easy. Of course, in the software you can click in 6 gallons preboil to figure the OG after the boil. without software, this is a bit harder.

As far as boiling longer, you will boil it down to the correct volume, but then you'll overboil your hops. Not a problem if it's a recipe that only has bittering hops (like a stout maybe), but you'll lose the flavoring hops and aroma hops- all the late addition hops will then be bittering hops. So, you don't want to do that probably. What you can do is to try to get at your target amount (I always start with 6 gallons) and start the timer at 60 minutes when your boil starts and start your hopping. If you lose more than a gallon an hour, you may consider adding some water to bring you up to to 5 gallons depending on your OG. If you don't boil off enough, well, then you have a 5.25 gallon batch. Either way, once you do it, you'll know your boil off rate and the next batch can be perfected!

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ljsbeer said:

Check your boil off rate with water first. Last weekend I started with 6.5 gal. and ended up with 4.75 gal. for a 1hr. boil. It was windy and cold so my boil off rate changed. It would be wise to test with water first to give you an idea of your boil off rate.

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Well, yes, that would actually tell you your efficiency. That's very useful for figuring recipes, and would help with the next recipe. However, I can't figure out it would be useful then for figuring out how much extract to add at the end of the boil.

If you have beersmith (and I highly recommend it), you could use that to figure out how much extract to add with the appropriate amout of water. But, my thinking is this- so, you know your efficiency is say, 68%. But after you add water to begin your boil, how do you know how much extract to add? If your efficiency in 4 gallons is 68%, that figure doesn't help you reach your OG. I don't know if I'm explaining what I mean or not. Maybe those guys can chime in here and clarify it a bit.

The efficiency you get from the mash is important- especially in formulating recipes for next time. You'll know what you can expect from the grains, so you'll know how much extract you'll need.

Edit- I'm moving this to the PM/AG thread. I'm not smart enough to figure this out- we need some more experienced minds!

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riored4v said:

yea, i think i might give it a test run under somewhat normal conditions so i can get an idea of where i'm at, and if its cold/windy one day i can add a tad more water.




I had the trial for Beersmith, which is now expired but I do plan on buying it to help me out.

I'm not sure if i'm confusing myself or if maybe i'm misunderstanding, but to me, i was under the impression that if tested the effeciency of my partial mash (pre topoff water) that I could use that number and punch that into beersmith. From there, i would add the ingredients into beersmith and that would tell me how much extract i would need to add.

I think i see what you're saying though with the 4 gallons @ 68%.. 4 gallons isn't going to give me a correct number to judge my full batch off of correct?? Does beersmith have an option for something like this?

Any help from the guru's would be really appreciated.

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YooperBrew said:

That is exactly what I was saying- until you take the preboil SG at the actual preboil volume, the SG is meaningless for adding the extract. Efficiency, though, is NOT meaningless, of course. It will be handy down the road, because you'll be able to dial in your processes to your equipment with your efficiency, and then you won't have to struggle with this! So, go ahead and take an SG for the efficiency, then top up to 6 gallons and take it again. (I'm sure there are ways to calculate the amount of DME from that first SG, however, I am not able to figure that out). After it's topped up, you will know then how much extract you'll need to hit your target SG.

Beersmith can help with figuring the IBUs in late extract addition, and efficiency. It can tell you how much extract you'll need to add, by playing with the recipe. I don't think it can figure the preboil efficiency along with the amount of water and DME to add to get you to a specific SG, though. I could be wrong- you could probably PM Beersmith or post in the software area, and Brad can answer that question.

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