Low OG on Caribu Slobber Extract Kit

First time brewing - had a blast yesterday with my caribou slobber extract kit. When I took the OG after the wort was cooled, it read 1.032. According to the documentation, the OG should be around 1.05 or so. I used a 2.5 gallon boil, when I cooled it and added it to the primary fermenter, I had about 2 gallons. I added 3 gallons to get the final volume up to 5 gallons. I shook the primary fermenter to “aerate” it then took the OG. When I got the OG of 1.032, I did think to check the hygrometer and it reads 1.000 with the tap water I used for the boil. I’m assuming that the reason for the low OG may be inadequate mixing of the malted sugars. Because I added 3 gallons of water, the sugars may be concentrated at the bottom. My question is this - if the sugars are indeed concentrated at the bottom of the primary fermenter, and the yeast is at the top, will this result in an incomplete conversion of sugars to alcohol? If so, can this be corrected in the secondary fermenting vessel?

Also - another nebe kind of question - I’m using a Big Mouth Bubbler primary fermenting vessel. I’m about 16 hrs into the primary fermenting and have abouut 2 inches of Krausen. When I put the arilock on yesterday, I put the red cap on the top of the airlock - does this prevent the release of CO2? Should the red cap be left off?

When you use all the LME and DME in a kit, and the volume is correct in the fermentor the OG will be as stated in the recipe with NB kits. You are right about the sugars not being thoroughly mixed. It will not make a difference in the fermentation. Even though ale yeasts are called top fermentors the entire volume of the fermentor will be full of yeast after active fermentation begins. The beer will turn a light creamy color due to the spread of the yeast cells.

The lid you have for the BMB probably is not making a good seal. The CO2 is escaping around the lid rather than going through the airlock. Not sure but there may be replacement lids available for the style of BMB you have. I’m sure someone will have definite information on the fix. The leak at the rim will have no effect on the fermentation.

The red cap should have small holes in it to allow the CO2 to escape. The purpose of the cap is to keep fruit flies and other such pests from swimming through the airlock and infecting the beer.

You said you shook to mix it up right before you checked OG, I’m a new Brewer, but I use a hydrometer at work daily… And the biggest mistake we have is aerated fluid. This will cause the reading to be low until it all surfaces. Just a thought.

I wouldn’t worry much about the low reading. Since this is a tried and true recipe, if you followed the instructions then the gravity should be close to what it says.

It’s easy to get incorrect readings if the extract is not mixed in enough. A few other reasons. Don’t use the plastic tube the hydrometer came in. Get a hydrometer flask. They are cheap enough and the hydrometer won’t stick to the side. Spin it around in the flask to get all the air bubbles out. Try to take the reading with the wort at 60°. The hydrometer should have come with a conversion chart for different temps though.

Good work checking the hydrometer with tap water. The exact test is distilled water at 60° but your tap water is close enough.

Keep the red cap on the bubbler, it does let the CO2 escape. I fill mine with cheap vodka even though it isn’t really necessary. Most of my little red caps seemed to have disappeared so I just use a piece of aluminum foil.

EDIT: One more thing. The yeast will find the sugar on the bottom but there is no reason you couldn’t have swirled the fermenter around slowly to mix it up and the yeast is probably bottom fermenting anyway.

try a full 6 gallon boil and use oxygen before you do add the yeast
me did find out in the beginning i did add water to get five gallons and took a reading the grav indeed to low .but now with a full boil no more issues on a low grav reading

1 Like