Low SG before boil

[n87]

http://www.brewersfriend.com/hydrometer-temp/

if you measured 1.032 at 65C, with your hydrometer which is calculated at 20C, your actual SG would be 1.048

 

[Poll]

Man I love this shit. There are so many scenarios and variables to making great beer. Thats what makes it so interesting and rewarding. Will never get sick of the feedback guys. Cheers.

 

[n87]

im guessing that was the answer you were looking for.... but was it the correct one?

 

[Poll]

Well not according to my hydrometer. i ended up boiling for 90 min and was left with 49 litres less bottom of boiler crap so 46 into fermenter. But still the FG was 1032!! i guess i will just let it run its course and learn from the vortexual experience not to mention the awesome useful information from you guys and go better again next time.

 

[indica86]

But still the FG was 1032!!

At what temperature?

 

[thisispants]

I just brewed a porter today and also had a very low sg pre boil... Incidentally this is the first time I've taken a pre boil measurement. I think mine was also temperature corrected at 1.030.

In the end I had a post boil sg at 1.046. The recipe calculated that i should have hit 1.049, so not quite, but should make a drinkable beer.

 

[manticle]

If you have the same gravity figure pre and post boil, something is being measured incorrectly.

 

[poggor]

Poll- I would definitely consider investing in a decent thermometer if you are going to be doing AG brewing- about 15-20$ on ebay.

 

[Moad]

or get a refractometer!

 

[TheWiggman]

Be wary that you'll lose a lot of liquid to grain absorbtion at about 1l/kg of grain. for this brew that's 11l. If you started with 40l, you'll end up with under 30l pre-sparge/top-up. Taking into account boil loss that means you'll be topping up with about 25l of water, which is heaps.

There are benefits to having a high water:grain ratio, and going higher (i.e. more water to grain) has more benefits than going lower with standard brews. Provided your vessel can handle it, next time try starting with your final volume i.e. 50l. You'll increase your chances of good efficiency this way.

As above though, sounds like you're having trouble with readings so hard to know exactly what's going on.

 

[thisispants]

Can anyone recommend a good thermometer? I have a traditional brewers thermometer but would love an electronic job that reads fairly quickly, there's a few on ebay but I don't know enough about thermometers to weed out the rubbish from the decent ones.

Also, is it fairly standard to use those waterproof probe thermometers where you can leave the probe in the mash for constant temperature readings?

 

[TheBlackAdder]

I picked up a candy thermometer from a cooking shop to stick in the boil for about $10

It seems accurate and was cheap plus is made specifically for going into boiling water. The only downside is that the temp range we brewers work in is only a small part of the scale which goes up to some ungodly temperature near 300C :S

It does have the issue of being a bit slow to take a reading and having to lift it back out to read it though.
Interested in seeing what others are using

 

[warra48]

Do yourself a favour, and get an automatic temperature compensating REFRACTOMETER. It only takes a dew drops of wort, and no need to read the temperature of your wort. Get one from the site sponsors, or take pot luck on fleabay.
If you have one of those, you wouldn't need to ask the question you have, and you'd be a happy brewer.

Alternatively, most brewing software has adjusting tools for temperature and hydrometer readings. I use BeerSmith2, and it includes that tool.

 

[manticle]

After you get the refrac, look up 'correcting refractometer readings in the presence of alcohol' so you can avoid that trap that new players regularly fall into.