Hydrometer readings

[Photomanliny]

OK I made the jump from extract to all-grain. When I did extract I had no issues with OG readings. Everything seemed to match the software. However now I went to all-grain and my OG levels are not near what beer smith says they should be. I am not sure why, but it is either a measuring issue, a mashing/sparging issue or somewhere in between.

What I want to ask is if what I am doing to measure is NOT correct. I have been draining the kettle via the ball valve after cooling. Then, after filling carboy to the correct volume, I have been using what wort is left in the kettle to fill the hydrometer tube. Are there less fermentables near the top of the wort after cooling? Should I be waiting until I aerate the wort and then use the beer thief in the carboy? Could I actually be achieving a higher original gravity that I am measuring?

Today's batch should have been 1.076 and I achieved 1.050 according to my reading. Of course, I didn't think to use the beer thief until after the yeast was pitched.

Thanks in advance for any replies.

 

[BryceL]

My guess is that you are getting a lower efficiency from your mash/sparge than the recipe is formulated for. With extract you will get pretty much the same gravity every time. With all grain, your gravity can vary greatly depending on your process. Once you get a few AG batches under your belt you can hone in on your efficiency and plug that into beersmith or other program.

 

[Photomanliny]

Well I still have to remain curious because after pitching yeast into a 5 gallon batch (6 gallon carboy) at around 10 PM, I woke up to a clogged air lock. Blow off tube is now attached. I remain curious because this batch "measured" 1.050 OG when I tested it via the method I mentioned above, and I have never had a beer with that OG ever come close to needing a blow off tube at that volume in that carboy. I still think it could be my testing method and I believe this "blow off" could be a clue.

Irish Red Ale in the Keg
Dry Irish Stout in Secondary
Rye PA "blowing off" in Primary

 

[broadbill]

Well I still have to remain curious because after pitching yeast into a 5 gallon batch (6 gallon carboy) at around 10 PM, I woke up yo a clogged air lock. Blow off tube is now attached. I remain curious because this batch "measured" 1.050 OG when I tested it via the method I mentioned above, and I have never had a beer with that OG ever come close to needing a blow off tube at that volume in that carboy. I still think it could be my testing method and I believe this "blow off" could be a clue.

Irish Red Ale in the Keg
Dry Irish Stout in Secondary
Rye PA "blowing off" in Primary

This means nothing relative to the situation you described in your OG.

Are you correcting for temperature?
What is your efficiency set too on BS?

 

[Photomanliny]

My efficiency is set to 72%. Temperature at reading was 70 degrees F.

I always did believe that the higher the OG (thus higher amount of sugars for the yeast to consume), the more Krausen would form and the greater chance of blow off. The only other beer I've ever had blow off was at 1.072 OG. I've had beers over 1.050 that never needed a blow off.

Am I confused in my logic here? Could a 1.050 beer blow off violently like this one is now?

The reasonm I questioned my testing logic was the same logic applied to sparging. You can't test the fir wort out of the tun, nor can you test the last. Well....you can "test" them but they are in no way accurate to the true OG. It's not possible that the last bit of wort in my drain off from the kettle has a lower OG than the first part?

 

[Photomanliny]

Oh and I use a two ten ten gallon round cooler set up with a bazooka screen for mashing/lautering.

 

[Clonefarmer]

My efficiency is set to 72%. Temperature at reading was 70 degrees F.

I always did believe that the higher the OG (thus higher amount of sugars for the yeast to consume), the more Krausen would form and the greater chance of blow off. The only other beer I've ever had blow off was at 1.072 OG. I've had beers over 1.050 that never needed a blow off.

Am I confused in my logic here? Could a 1.050 beer blow off violently like this one is now?

The reasonm I questioned my testing logic was the same logic applied to sparging. You can't test the fir wort out of the tun, nor can you test the last. Well....you can "test" them but they are in no way accurate to the true OG. It's not possible that the last bit of wort in my drain off from the kettle has a lower OG than the first part?

A low gravity beer can also have a vigorous fermentation that requires a blow off. Hefeweizen are often low ABV and are notorious for explosive fermentation. Yeast is an unpredictable living thing so it's not a good indicator. Trust your instruments.

 

[J8D]

Like Broadbill said, your fermentation activity while perhaps a correlation, is not a causation of blowoff activity.

Hydrometer readings have cursed me a time or two. It is standard practice to take a reading once your wort is done boiling, but this really only tells you if you are good or whether your numbers are off. The only correction you can make (talking all grain) is if your numbers are high, in which case you could add water. However this now reduces your IBUs and changes your hop profile (assuming your final volume was spot on). If your numbers are low, you could in theory re-heat and boil off more (I am not sure of the negatives of this practice but I assume there are some).

When doing your readings, make sure you adjust for temperature (several calculators out there including some for your smart phone). I would recommend a refractometer as well which will allow you to do mid boil readings without having to remove and cool the wort sample to use the hydrometer. Bobby sells a good one that has simplified my gravity readings and allowed me to do gravity corrections prior to my flavor and aroma hop additions (allowing me to not destroy my hop profile). Either way, you still made beer. Once you have your processes down, your numbers should fall into place. Just be sure and record the data. Assuming you are using some sort of brew software go back in and run the numbers to see what your efficiency was and consider adjusting for your next brew. Track those numbers too. If you stay consistant in your processes, and use the same grain mill, you should get consistent efficiency (unless you do some bizarre recipe). You can then use your actual efficiency to calculate your recipes and hit your numbers (or close to it). Hope this helps. Here is the link to Bobby's site for the refractometer.

Refractometer ATC- Brix/Gravity

 

[Yooper]

There are a couple of things to do right away in your next batch. One, make sure your volumes are correct. Secondly, once you get all the wort (first and sparge runnings) into the kettle, pull a sample of the wort and cool it. I just stick mine in a skinny pitcher with ice water and let it cool. THEN take a hydrometer sample when the wort is under 90 degrees. (You can then use a temperature correction chart to get the actual reading, but the wort has to be under 90 degrees).

If you know your volume and you know your preboil OG, you can adjust the wort right then, maybe by reducing your hops or adding some dry extract.

The first thing I'd do though is adjust your efficiency in Beersmith! If you're not hitting 72%, no reason to have it set for that! In Beersmith, go into the last recipe and lower the efficiency % until you see the OG you actually got in the "estimated OG" and formulate your new recipes for the actual efficiency you got.

Hope that helps!