adding fruit to secondary ferm.

Hi, I've never brewed using fruit before. I'm going to be adding some fruit to the secondary fermenter and had two questions.

1. Do I need to check the gravity 4 times, 3, or just 2? I wasn't sure if I would have to measure it after I add the fruit or if I should just check it after both fermentations have taken place and compare to the original?

2. Should I toss a good part of the yeast cake in the 2nd to make sure that there's enough yeast to finish the 2nd fermentation,should i buy some new yeast, or should i just leave the cake on the bottom not buy any more yeast and hope that there is still enough yeast for completing the fermentation?

Thanks for the help look forward to the responses.

Most fruit has very little sugar in it, 10% by weight or so. Checking the gravity isn't necessary, nor is extra yeast. As an example, I have a bag of frozen blueberries. A serving is 140 grams. 17 grams of sugar or 12%. Two pounds of them would add less to the batch than your priming sugar.

Well, I haven't used fruit a ton of times so this is just from my experience. You probably need to freeze the fruit and then puree it before adding to the secondary. Plain saccharomyces cannot break down the cell walls in fruit so they need to be ruptured via freezing/pureeing. The freezing will also help with killing most of anything on the fruit. I'd add the fruit to the secondary and then rack my beer on top of it to avoid splashing the fruit into the beer and causing oxidation.

You might try pitching some of your yeast cake when you rack, it depends on how far along the beer is and how much the yeast has flocculated out. Last time I used fruit all I did was use the tip of the auto siphon to stir up some of the sediment and transferred it into the secondary with the final brew.

I would check the gravity before adding fruit, after adding fruit and then probably 5-7 days later. Remember that it takes yeast a little while longer to break down the sugars and various compounds in fruit than it does with malt or malt extract. One mistake I made was not letting my batch sit long enough and my bottles ended up over carbonated. So err on the side of caution.

What type of fruit are you using? How many pounds? What kind of beer are you adding it to?

thanks for the help. I never noticed the amount of sugar in cherries that it would have been hire than what it is. I'm brewing a belgium ale but I missed my og and ended up with 1.081.