Fermentation speed deference between similar juice from apples from 2 trees...

[OffbeatBrew]

So I picked apples at two friends houses the other week. They live in the same neighborhood, just a few hundred feet between houses. I juiced the apples from each tree separately. Each tree had similar looking and tasting apples. The each had a ph of 3.5 (based upon oh strips), each had the same amount of campden tablets or volume, each had D47 yeast, and they are next to each other, so same environment. The only difference was a marginally higher gravity in one than the other (Brix of 14.4 vs 13.4). The one with he lower gravity absolutely took off, while the other one had a longer lag phase and is slowly puttering along.

So, out of curiosity, what other elements in the juice may have resulted in this noticeable difference? Nitrogen content? Tannin level? Something else? Thoughts?

It will be interesting to see which ends up having a better end result!

 

[RPh_Guy]

Nitrogen content?

This, or difference with the yeast packet, or slight difference with rehydration, or slight temperature difference, or a butterfly flapped its wings nearby and the wind hit one of the fermenters.

 

[Maylar]

Nitrogen content?

That's quite possible. Especially if one of the trees has had fertilizer, but even if not the nitrogen in the soil can be different. Also the apples themselves will vary with the variety.
And if you still have them, check the use-by dates on the yeast packets. One may be older and less viable.

 

[OffbeatBrew]

This, or difference with the yeast packet, or slight difference with rehydration, or slight temperature difference, or a butterfly flapped its wings nearby and the wind hit one of the fermenters.

I hadn't considered the butterfly effect. Thanks, Jeff Goldbloom!

 

[OffbeatBrew]

That's quite possible. Especially if one of the trees has had fertilizer, but even if not the nitrogen in the soil can be different. Also the apples themselves will vary with the variety.
And if you still have them, check the use-by dates on the yeast packets. One may be older and less viable.

I bought both packets at the same time from my LHBS. But being in AZ, stuff gets shipped through Phoenix, and I'm sure that heat can affect some yeast packets more than others.

 

[ten80]

I'd say differing free amino nitrogen, given that pH was the same. Apple juice brix is not high enough to affect fermentation start. Dry yeast is super hardy, even when the packets are exposed to room temp.

 

[OffbeatBrew]

Well Phoenix definitely gets above room temp
Just a follow up on this. I actually ended up racking the fast-fermenting cider into a secondary so I can pumpkin spice it for fall (reserved a gallon to taste alone). I racked the slower fermenting cider on top of the lees and it just took off fermenting quickly. Still not sure if the yeast was happier before I ever pitched it or if the higher nutrient content in the fast fermenting cider made the yeast cake happy and hungry

 

[madscientist451]

So, out of curiosity, what other elements in the juice may have resulted in this noticeable difference? Nitrogen content? Tannin level? Something else? Thoughts?

The degree of ripeness could make a difference. You already indicated that there was a difference in the sugar content of the two juices. Apples will continue to ripen somewhat after they are picked. I usually store any apples I buy (or scrounge) for cider 3-4 weeks in a cool place before milling and pressing.
Note that there are very few apples that make a decent single variety cider. Its likely the yard trees in your neighborhood are some kind of dessert apple that if used, would be part of a blend.