Help with Original Gravity.

all grain? or extract?

Extract is pretty straight forward. If you add the right amount of extract and your final volume is correct (post-boil), it's almost impossible to miss the target.

All-grain is tougher to nail down, but it comes down to knowing your system efficiency (because a recipe designed around 80% efficiency will use less grain to achieve the target OG than would be needed for systems with lower efficiency). Once you have some understanding of that, then it's again just a matter of weighing accurately and hitting your pre- and post boil volume targets.

It's not easy to summarize everything that goes in to it succinctly because there are many factors that can impact your extraction efficiency - chief among them the quality of the crush on your barley, temperature, pH, etc.

Your OG was almost 20% off from the target - but... where did the target come from? What assumptions went in to that number? Can you share the recipe?

I'd add that the easiest way to 'miss' your target is to measure your volumes poorly. Over-sparging and collecting too much runoff will dilute your wort and give you a low OG (and larger volume of wort than intended). If that happens, you can 'fix' it by adjusting your boil time to concentrate the wort. Just make sure the additional boil time occurs BEFORE you add your first hop addition.

 

Knowing the efficiency of your system and then adjusting your grain amount accordingly to get your desired gravity would be the most basic answer. If you're asking how to make your system more efficient, then you'll need to describe your current process.

 

With extract, you either did not mix completely or your volume calculations are way off.

Provide a little more details on your process and we can help figure out your problem. But, given it is extract, it is probably not a true problem.

 

I don't see any on that site with an OG of 1.058? All are either higher (1.070) or a bit lower. In any case, if your gravity is low on an extract kit - you probably either added too much water, didn't boil off enough, and/or didn't adjust your hydrometer for temperature.

 

If your OG was low when using extract, three things to look at:

1. Was it a full boil or did you have to add top-off water to attain the correct volume for the recipe? If water was added, was it mixed thoroughly when your took your gravity reading.
2. Are you certain that your final liquid volume was real close to the recipe's volume? Boil-off, topping off, etc, can lead to wrong volume amounts.
3. To a lesser degree for gravity point difference errors, was the wort at 60 degrees (or adjusted for the actual temp reading), or have you checked the calibration of your hydrometer for water to be 1,000?

 

Always boil the full volume if you're able (i.e. if your pot is large enough). For a 5 gallon batch, your total volume pre-boil (*after* adding your extract) should be between 6 and 6.5 gallons - depending on how vigorous your boil is. The reason your recipe specifies a range of volumes is because some people can only do partial boils (as you did) - where they might boil 2 or 3 gallons and dilute to volume at the end w/ water.

Your gravity was low for a couple reasons.

1. When you're doing a partial boil, your wort is very concentrated. Every time you have a boil-over, some of that concentrated wort is lost. That is, some of your extract is lost! That means gravity points are lost. Basically, you end up needing more water to get to your final volume, so everything is diluted a bit. In order to hit your target with a partial boil, everything you put into the kettle needs to stay there during the boil AND be transferred to your fermentor afterward.

If you do a full boil - one of several advantages is that if you have a boil-over, your potential OG doesn't change at all. You just lose a bit of volume. (obviously, this doesn't apply if you then add water afterward to get back the volume you lost!) IMO, it's better to have a bit less beer at your desired OG than it is to have exactly 5 gallons of diluted beer, but TEHO.

2. Hydrometer readings need to be corrected for temperature. If you measured your wort at 70F, the error is relatively small (only about 1 point). But if you measure it shortly after the end of your boil, say at 160F... the error is more like 21 points (i.e. your reading will be 21 points lower than the actual gravity).

There are calculators you can use in the future: http://www.brewersfriend.com/hydrometer-temp/

p.s. next time don't boil the water before (or while) steeping your grains. Boiling small amounts of grain in large volumes of water is not a good idea. There's a risk of extracting harsh tannins that can make your beer astringent. Better to steep them in a smaller volume of water at ~ 155F for ~ 30 min, then add this steeping liquid to your kettle after removing the grains.

 

Am I understanding that correctly, you steeped your grains in boiling temperature water? That is much too hot. You should steep in water that is in the range of 150 – 170 degrees F.

I would highly recommend that you read the book How to Brew. The printed book would be better since it contains updated material but at a minimum read the on-line version: http://howtobrew.com/

Cheers!

 

You need to nail the post-boil volume for the OG to be correct. You may also need to adjust the reading for temperature. OG reads lower on a hydrometer at temperatures above 70 F.

 

no problem.

 

See above in bold.