What do you do if your OG doesn't match??

**phrogpilot73** · 02-22-2009, 03:50 PM

So I brewed up a Russian Imperial Stout kit a couple weeks back. The bottom end of the OG was 1.070. Mine measured at 1.052. I went ahead and pressed... I figure that it just won't be as high an alcohol content. Should I expect that the FG will be lower as well, or will it probably hit the target FG?

TexasSpartan · 02-22-2009, 03:54 PM

Did you adjust for the temperature? I know that can make a difference. Not sure about that big a difference. Someone more knowledgeable than me can tell you that.

Eves · 02-22-2009, 03:57 PM

Was it an extract kit? If so them perhaps the extract(s) weren't fully mixed and the sample you took ended up with less fermentables.

The temp of the sample makes 'some' difference as well. Though even if your temp was 100F it only messes so that your 1.052 is actually 1.058 <- So not that big of a change from temp alone...but still a potential factor.

EDIT: I am not an AG brewer so I can't speak for that form of brewing but I do know that if you use all of your ingredients for your kit then you will almost definitely end up with the expected ABV. Assuming your wort wasn't mixed well (as in your kit is an extract kit) then don't fret. The yeast will find those fermentables in the wort and you'll end up with an FG close to what you expect and all will be well.

Pharmguy · 02-22-2009, 04:00 PM

I had the same problem with my 1st two kits. The 2 replies I received on the subject were 1) the extract in the kit was older and 2) I didnt stir it up enough. Maybe both. Anyway, your OG is probably closer to the kit goal than you measured. If it is really 1.052 your Fg should be around 1.012.

**pompeiisneaks** · 02-22-2009, 04:32 PM

From what I've read/heard, I agree w/ whats been said too. Usually its either that the mixture of malt and water wasn't fully mixed well, and you have "denser" and "lighter" areas. Temperature of the hydrometer reading does matter, and although at say 100degF it may not seem like much, if its really hot, say 180, its a significant difference. If you know about what the water temps were when you did the OG, it can be adjusted easily. I use my brewing software's tool. BeerAlchemy says, for example that if your OG was 1.052 at 180 deg F, thats actually 1.081 at normal OG temp readings.... I don't have a clue what your reading was, but it can drastically affect the reading if you're pretty hot still w/ the wort.

**phrogpilot73** · 02-22-2009, 11:12 PM

I thought I had mixed it up pretty good, I boiled 2 gallons with the extract then poured it in on top of 2 gallons of water. Poured one more gallon to top it off. The temp of the wort when I added it to the water was 100 deg, and the temp of the water in the carboy was 72. Still not a huge difference, and still below what it was supposed to be. I didn't measure the temp of the water/wort after I aerated. I should have, if I guessed it would be about 85. So that would be a corrected OG of 1.055 (according to Beer Smith). Still low. We'll see. Fermentation did happen (I had a blow off), and I rehydrated my yeast first. I'll look sometime this week to see what the FG is...

impatient · 02-22-2009, 11:18 PM

Since you are calling it a kit. The gravity should come out dead on with extracts. Must have been something wrong in the measurement. I wouldn't even check my OG with a kit. I would just assume that the original gravity is what was stated in the recipe. I would however, check the gravity at bottling time after 2 weeks in primary and 2 weeks in secondary.