Targeting OG

[BARL Brewing]

When trying to hit the target OG during the boil using a hydrometer what is the best way hit that number and determine when to start your hop additions?
For example: as I boil the wert it will concentrate raising the gravity correct? When is an appropriate time to pull off a sample, cool it and take a hydrometer reading?
Now after taking the gravity I’m under the target OG, ill either add DME or boil longer to concentrate the wert even more depending on the boil volume. If over the target OG i assume ill just add water to thin out the wert. Doesn’t doing this change the duration of the boil and will affect the hop addition times.
I don’t know if there is a good answer (maybe I’m way off) or if it’s more just knowing your system.

Brian

[jward]

...or if it’s more just knowing your system.

Yes, you want to learn your system. Some of this depends on what you mean by target gravity. I think of that as the original gravity(OG) that fermentation starts at. You don't want to boil down to this and then boil more with the hop edditions etc. Some styles may call for a long boil for higher gravity and to develop flavor components. You want to sparge to hit your pre-boil gravity as close as you can by learning your sparge/system efficiency. You want to learn how much evaporation or boil off you get. You use that to figure out your desired pre-boil gravity based on the recipe OG.

I measure the gravity of the wort a few times when I'm busy or often when I'm not. A refractometer makes this a lot easier. I used to cool the sample some and use the chart that comes with the hydrometer to adjust for sample's temperature. How do you sparge? When I fly sparged I kept an eye on the runnings to avoid over sparging. Now when I batch sparge I'll measure the volume and gravity of the first sparge to decide how much water to use with the second batch.

I would suggest getting a copy of Beer Smith or ProMash software. Both have trial versions. Plug in your recipe and see what is says you should do and compare it to your actual measurements. They have calculators to help figure out dilutions and boil-off.

[brahn]

I very rarely measure pre-boil gravity. I know my system pretty well so that I have a good enough idea of where the beer's going to end up and I just take what I get.

[BARL Brewing]

I very rarely measure pre-boil gravity. I know my system pretty well so that I have a good enough idea of where the beer's going to end up and I just take what I get.

That’s what I was thinking and it's how I’ve done it so far, but I was thinking that specific styles call for specific gravity’s and if brewing to style it may be more important to be spot on.

That’s what happens when my mind wanders.

[bwarbiany]

FIrst, using a hydrometer for this task will be a major pain in the arse... If you really want to go this route, you want a refractometer:

http://cgi.ebay.com/NEW-0-32-ATC-Brix-R ... 5ad9e6290c

But as pointed you, you basically really need to know your system... Every brewhouse is different. Boiloff rate is the main key. What I'd do is buy the refractometer, and then do about 3-4 batches where you measure gravity at start of boil, 30 minutes into boil, and at the end. That will give you a good sense of how quickly the gravity increases.

For most extract brewers, gravity issues are volume-driven. I.e. if your recipe calls for 1.050 and you measure 1.054, you are at a lower volume than targeted. If you measure 1.045, you're over on your volume.

For all-grain, obviously it's a lot more complex, and measuring gravity can be useful for sparging (i.e. to make sure you don't oversparge) as well as better targeting how close you are to pre-boil OG.

But really, most of these measuring tools are best to help you refine your process, rather than perform day-of-brewing adjustments. The best way to brew is to know your system well enough that you know how to hit your numbers without changing boil duration or adding extra material -- these things change the taste of your beer, making it something other than the initial recipe. In extreme cases, of course, changing the recipe might be necessary, but it's not plan A.

[backyard brewer]

Learn your system and then learn to use a program like Beersmith or Promash. IMHO it doesn't matter what your efficiency is as long as it's consistent. While I'd rather have efficiency in the 80's, if I was able to nail 60% each and every time, then I could plug that number into Promash and it would adjsut all my recipies for my Brewhouse Efficiency and I can plug in someone else's recipe and quickly adjust it for my brewery.

[BrewMasterBrad]

What they said!!

Brewing more and keeping good recores is key. I now know after 60 batches on my 10 gallon system, that I get about 72% efficiency, so I plan as such. If I am a little bit off, I don't really care. I don't try to make adjustments on the fly since I believe that it will just mess me up with my process. The key is being consistent. For example, my last three efficiency numbers were 72.36, 72.21, and 73.24. So I know that when I calculate my recipes on BeerSmith for 72% efficiency, I will come in pretty close to what I have planned for.