OG and FG readings question

[kennya]

Hey all. I have brewed about 25 extract kits and knock on wood, I haven't messed any up to where they taste terrible. However, I have only had 1 or 2 kits where I have hit the OG exactly. I have to do partial boils because i only have a 5 gal pot. So for example, if my OG is supposed to be 1.050, I have been anywhere from 1.040 to 1.060. Some times its only a .001 or .002 either way, but sometimes like my example, it could be up to a .01 off either way. I don't know why my OG readings are not more consistent.

To go along with this, I just brewed a pale ale last weekend and when I added the wort and the top off water to my fermenter, I took my OG reading. The recipe called for a 1.050 and I came in at 1.060. I thought, after looking at my sample, that maybe there was to much malt or hops in my sample. So I stirred the wort up real good, and immediately took another sample. Sample was much clearer, but this time my sample was 1.040. I dont get it... I am going to make the switch to all grain later this year, and one of the things I want to accomplish before that is hitting my OG and FG.

With all of that said, I rarley, if ever, hit my FG either. Im ususlly close, within .005 either way, but I really want to tighten that up.

Thanks for your comments and assistance!

 

[Revvy]

This should explain your og issues....Attention new brewers, yes your original gravity reading is wrong. Don't panic.

Not hitting your FG perfectly is quite normal, we're dealing with yeast, and some sugars that are unfermentable in extract. Some extract batches get stopped at 1.020....

You can always make sure you're pitching the right amount of yeast for the starting gravity, make sure you give the wort plenty of oxygen at pitching time, make sure you're temp isn't too cool amd give the yeast plenty of time to do it's job... but you're still dealing with living creatures and there's always going to be a certain "wild card factor" at play.

But the fact that you're talking .005 is not something I'd sweat, really.

 

[theseeker4]

Hey all. I have brewed about 25 extract kits and knock on wood, I haven't messed any up to where they taste terrible. However, I have only had 1 or 2 kits where I have hit the OG exactly. I have to do partial boils because i only have a 5 gal pot. So for example, if my OG is supposed to be 1.050, I have been anywhere from 1.040 to 1.060. Some times its only a .001 or .002 either way, but sometimes like my example, it could be up to a .01 off either way. I don't know why my OG readings are not more consistent.

To go along with this, I just brewed a pale ale last weekend and when I added the wort and the top off water to my fermenter, I took my OG reading. The recipe called for a 1.050 and I came in at 1.060. I thought, after looking at my sample, that maybe there was to much malt or hops in my sample. So I stirred the wort up real good, and immediately took another sample. Sample was much clearer, but this time my sample was 1.040. I dont get it... I am going to make the switch to all grain later this year, and one of the things I want to accomplish before that is hitting my OG and FG.

With all of that said, I rarley, if ever, hit my FG either. Im ususlly close, within .005 either way, but I really want to tighten that up.

Thanks for your comments and assistance!

How exact are your volume measurements? There is no efficiency factor in extract brewing, so you are starting with a certain amount of sugar, and your actual gravity is determined by your volume. To put it another way, if you have exactly 5 gallons of wort, you added all the extract that you were supposed to, and the recipe calls for 5 gallons of 1.060 wort, your actual gravity is 1.060, regardless of what your hydrometer said.

The biggest issue with measuring extract kit partial boil OGs is that it is very difficult to mix the top up water with the wort, so you might stir it for a while, and take a sample, but your sample will still be off because the wort is still stratified.

Stop worrying about measuring original gravity for extract recipes, and just make sure your volumes are accurate. If the volume is good, your gravity will be the predicted gravity. Then you can measure your final gravity to determine the ABV and attenuation.

In addition, you really shouldn't worry about being off by .001 or .002, as your error is measurement is at least that much, especially on the volume side.

 

[Double_D]

Your example of sugar stratification is probably your problem. The only variable in your extract kits is water..as long as you accurately measure you water volumes you should hit your numbers.

Are you doing mini mash? That could change things too.

Well, they beat me to it. typing on a tablet

 

[kennya]

I sure appreciate the comments. Every time I take a reading, I always feel a little defeated when I am off. I know that there are variables with extract partial boil brewing that are out of my control, but it still bugs me! But, after reading the above comments, I wont let it get me down anymore. Thanks!

 

[Morrey]

I sure appreciate the comments. Every time I take a reading, I always feel a little defeated when I am off. I know that there are variables with extract partial boil brewing that are out of my control, but it still bugs me! But, after reading the above comments, I wont let it get me down anymore. Thanks!

I can already hear you from here, but if you follow your extract kit's directions specifically, the hydrometer reading is nice, but not critically important. Unless you plan to add more sugars or malts to raise OG, or more water to lower OG, you should be fine, just follow kit instructions exactly. A kit is like a boxed cake mix...the ingredients are already pre-assembled to take the guess work out.

I used extract kits mostly when I got started, and the OG drove me nuts if it was off by any little bit. The main thing is your hydrometer is calibrated to read at a specific temp, and that temp is usually lower than we pitch ale yeast at. This accounts for some difference right off the bat.

I talked with my LHBS guru and he offered some good advice. Put the hydrometer in a drawer and follow extract kit directions. When you begin to brew all grains (maybe partial mash brews), bring it out and use it wisely. I followed his advice and now enjoy the process instead of getting nervous over small variations.

You did say one thing...."I may have too much hops in my wort when I take a reading". I always strain my wort by putting a 5 gallon sanitized paint strainer bag in the FV when pouring from my boil kettle. This bag catches most of the trub from the initial boil and makes for a much cleaneer wort when you rack into secondary after primary fermentation. I buy my strainer bags at Lowes for a few bucks for 2 pk. They can be reused many times with careful cleaning.

 

[kennya]

About 3 batches ago, I started using a hop bag for all my hop additions. So I have cut out most of the hop trub. When I started buying hop bags, I also found a good platic strainer that I use to strain my wort. Come does get through, but I am guessing it is more of the thicker malt that I am seeing in my test jar. Thanks for checking in Morrey, I appreciate all the advice!