SG/ Gravity Issues

[Somebirs]

Hi everyone. First of all, let me say that I have been reading through the posts on this site for several months now and have learned a great deal. I consider the combination of this site and the Palmer book to be mandatory reading for beginning brewers.

I am now into my sixth batch, and I believe I have steadily improved my techniques and results with every batch. My last two batches, for example, I have focused more on temperature control, which, in Southern California during the summer, is a pretty big issue. My most recent batch was brewed last weekend and is currently sitting in a bath, fluctuating between 68-70 degrees F. This is a real improvement over my first few batches, which I really wasn't able to keep under 76 or so, but for which I used yeasts from my LHBS that were recommended at the highest temps possible.

But I digress. My issue is that it's time for me to get better at taking gravity readings so that I have more control over the process. Generally, I have had a fairly difficult time taking readings. I think I have a decent quality hydrometer. For the first couple of batches, I really didn't know what I was doing. I took readings with hot wort and didn't adjust for temperature, I took samples from unmixed wort (I have only done extract and partial mash so far), I have taken samples from the yeast cake because I have had a hard time physically getting readings out of my carboy. You get the picture. Basically, I have been flying blind, but my beers have been pretty decent, actually. I just want to improve.

So... Here are my questions:

1. Best way to physically take readings out of a glass carboy, and when? Wine thief? Long turkey baster? Take readings only after a couple weeks when you think fermentation might be done, and then a few days later to confirm?

2. Do you take an OG reading immediately after brewing an extract or partial mash wort, or is it pretty much senseless and you just use the estimated OG on the recipe if you trust it? I read somewhere that the solution will pretty much not be mixed properly until the ferment starts anyway. Which leads me to my next question.

3. Is the OG before or after the yeast is pitched?

4. Any other SG tips for a noob?

Thanks all!

 

[dnslater]

I generally don't take an O.G. with an extract kit, as it should match the kit instructions, and sometimes you get deceptive readings if you do a partial boil and don't mix well. I would definitely take one with a partial mash as your efficiency may not match the recipe. Always do it prior to pitching so you don't wast yeast checking gravity, as you don't want to pour the liquid back in. A yeast starter won't effect gravity much.

 

[deggenbe]

1) i don't have a thief. But i use my bottling wand and tube upside down as a thief for gravity readings from my carboy's (using my thumb to hold the nossle to take liquid, and then releasing to pull it out)
since these tools of mine are always sanitized or are being sanitized, it works great, and i didn't have to spend extra money on an extra tool that does the same thing as something i had in my possession already. (i like getting more than 1 purpose out of something)

2) never hurts to take a OG reading partial, extract or all grain to see where everything is starting at.

3) i'd say before as to not skewer any readings.

4) i like to get several temp readings of all my SG's and OG/FG's
just let em fix themselves to room temp naturally then use a calc. i like to see the difference change from mash/boil/ferm temps. gives a good feel for how things change.

 

[ChaosStout]

Let your wort cool down to pitching temp befor you take an SG reading or it will be off. The best way to get a SG reading from a carboy is to put your hydrometer in the thief, put thief in carboy and shake it up and down. This will fill it. When it gets to a level wher I can grab the hydrometer in give it a spin and dunk it several times and look at the reading each time. Also do this befor you pitch

 

[h22lude]

So... Here are my questions:

1. Best way to physically take readings out of a glass carboy, and when? Wine thief? Long turkey baster? Take readings only after a couple weeks when you think fermentation might be done, and then a few days later to confirm?

2. Do you take an OG reading immediately after brewing an extract or partial mash wort, or is it pretty much senseless and you just use the estimated OG on the recipe if you trust it? I read somewhere that the solution will pretty much not be mixed properly until the ferment starts anyway. Which leads me to my next question.

3. Is the OG before or after the yeast is pitched?

4. Any other SG tips for a noob?

Thanks all!

1) I use a wine thief but you can use a turkey baster as well if you have a test cylinder like this...http://www.austinhomebrew.com/product_info.php?products_id=11615 I take one right before pitching when the temp is around 70 and then I wait 3 or 4 weeks and then I'll take 1 a day for 3 days to make sure fermentation is done. No need to take any more than that.

2) I take one right before pitching no matter what I use for my malt (extract or partial). And if you are using a hydrometer, make sure the temp is around 65 to 70. I just like to know I was close to the estimated. You can screw it up and it is just nice to know you are close.

3) Right before the yeast is pitched when the wort is chilled.

4) Besides that there really is nothing to it. Whether you are taking a reading or not, you still have to top off to 5 gallons, you still have to shake the crap out of the bucket to aerate it and you still have to chill it down to pitching temps...so you might as well take a quick reading. It shouldn't take you more than 30 seconds.

 

[Somebirs]

Thank you all for your quick responses! Very good advice.

Love that this hobby is a mix of science, gastronomy, do it yourself projects, and intoxication.

 

[fdben]

I use a wine thief and find it very handy. I pull the sample, let it degas and come to room temperature (if I'm pulling it after the boil or mash) then drop the hydrometer in.

I've noticed that bubbles clinging to the hydrometer can definitely change your reading, so watch out for that.

Also, the previously mentioned tip about shaking the thief is bang on. That's exactly what I do! works great.