Low OG

[amartinez]

Today I brewed my 7th batch, one of the Austin Homebrew Anniversary kits, but I've been starting to notice a trend of having lower than expected OGs. The first 3 were pretty close, only about .005 or less off, but the last few have been about twice that. With higher estimated OGs I seem to miss the mark by a lot, like today I was shooting for 1.051 and I only ended up at 1.042. So far I've been loving the beer I've made so I haven't put too much worry into it, but I thought I might see if anybody had any thoughts about how to boost them up to what's expected. So far I've gotten kits from AHS and MoreBeer and I wasn't sure if they might inflate their numbers or something.

I have thought about just adding in some extra DME, but then that's changing the recipe so it's more of a work around than a fix.

 

[janivar123]

You use the all grain kit or partial mash?
If extract kit it is measuring that is the problem as those are almost impossible to measure correctly(much easyer to estimate from the ingredient list)

Sound like you have a bit lower effishensy on your mash then the kit assumes so i guess using less water or boiling off more would do the trick

 

[NyPDFustercluck]

another thought is when are you taking the sample? if you're taking it from the fermenter after you've added your top-off water, it's pretty easy to get a sample that hasnt been completely mixed. This can lead to significant inaccuracy in your OG readings. Make sure you are getting a good mix, either by having your top-off water already in the fermentor before you rack, or stirring completely before measuring. As Janivar said, if you're doing extract kits, the gravity is pretty hard to mess up as long as you're using the correct volumes, so if you are, RDWHAHB, it's going to be beer no matter what the gravity is

 

[amartinez]

I knew I was leaving out some details, I've been doing partial mash so far and I'm taking the sample from the fermenter but I've been doing a full boil so I haven't needed any top off water.

Another thing I thought of this morning, is that I'm not losing too much water during the boil. I start out with 6 gallons and about 5 to 5.5 gallons end up in the fermenter with a good half inch left in the kettle. I do leave the lid on during the boil, it has a vent that pours out steam, but most of the evaporation is probably kept in there. I think I might try removing the lid once it comes to a boil and see if I get some better results.

 

[ThePearsonFam]

Take the lid off. You want the vapor to escape in order to drive off DMS precursors and other nasties.

 

[amartinez]

Ok, thanks for the advice everybody.

This gives me an excuse to brew again this weekend.

 

[amartinez]

A bit of a zombie thread, but I brewed a Belgian Golden ale this weekend with the lid off for the boil and I was dead on for the estimated OG.

Thanks all!

 

[ThePearsonFam]

Congrats!

Have you taken the time to read (or listen on podcast) about DMS? Here's the Brew Strong podcast about boiling. I think it's the one that talks about takingthe lid off and gives information about DMS.

http://thebrewingnetwork.com/shows/600

I think that's the show...