Just racked a mead, SpGr increase?

[jkuhl]

This is mostly just out of curiosity but I have a mead that's been going for about a month now. A raspberry mead essentially. Fermented for two weeks, racked it off the raspberries since they started looking janky (and yeah I know it's just krausen but everything I read said to rack it after ~2 weeks or so anyways. When I racked it (and that was about two weeks ago) it was at 1.035 from a starting gravity of 1.085. I saw a ton of sediment today as I took another SpGr reading (was thinking of possibly bottling it), so I racked it a third time and measured it and got 1.042. This one used a Lalbrew Ale Yeast (because the recipe said ale yeast, but knowing what I know now I'd probably use a wine yeast.)

I was just wondering what might have triggered such a large increase, from 1.035 to 1.042. If that's a new fermentation kick starting I clearly don't want to bottle it yet (and for safety sake, whatever the reason I won't bottle until I see the same number twice after taking readings a week a part.)

I did not give the yeast any extra nutrients or add any extra sugars or fruits since the original brew. They've only had the starting honey and raspberries to work with.

Thanks

 

[bushman101]

Did you use real raspberries? If you did, the berries may not have been crushed up enough for the sugar inside to be fully mixed. This would cause a low initial gravity. Over time, the sugar will dissolve out, thus increasing the Specific Gravity

 

[jkuhl]

That makes perfect sense. That's probably what it was. I did crush them a bit but that explanation makes sense.

I did read about freezing and thawing them before adding them, probably gonna do that in future batches. That and pectolase.

 

[dwhite60]

Hydrometer or refractometer?

 

[jkuhl]

Hydrometer

 

[hotbeer]

What is the ambient temperature where you are keeping the fermenter? Is it a fairly stable temp or might it be dropping low enough occasionally to cause the yeast to slow down or stop working completely?

 

[jkuhl]

It generally stays about 75F in my apartment, my meads resides in my closet, which is the only space I've got that stays dark and has room for a carboy.

Only time the temp changes much is when I'm cooking, which can cause it to get humid enough for me to turn the AC on for an hour but I don't think that's significant enough.

 

[hotbeer]

I don't know why your SG may have increased between readings if you didn't add anything else. However if your temps drop too much at night or any other time, then the yeast might be slowing up on their activity.

I don't know how much of a temp swing is too much, but generally I feel that if yeast are going good a a particular ambient temp, then letting the temp unintentionally fall at some point is more harm than good. They'll close up shop on converting sugar to alcohol and might take a while to decide to start at it again.

An SG of 1.035 seems high to me and 1.042 even higher. But I just barely know what mead is much less anything about what it should ferment to. I'm just barely understanding beer.

 

[JimRausch]

An SG of 1.035 seems high to me and 1.042 even higher.

Agreed. Don't bottle it now, or you'll have blown-out corks, or exploded bottles. She's not done by a long shot. With a OG of 1.085, almost any yeast should take it down to 1.000. Mistake not adding any nutrients. Treat your yeast well and they will do their job happily. I'd add a teaspoon of yeast nutrient, agitate well to let in some O2, and keep her somewhere warm. 75 is plenty warm.