Can a tap hole heal over during the season

[Loon Lake Louie]

I have some 5/16 taps that were flowing pretty good at the start of the season. Then the sap stopped flowing for about 2 and a half weeks. Now it's warming again and the sap is flowing pretty good again, but some of the taps aren't. I was wondering if the holes may have healed/sealed over. Any thoughts?

[adk1]

Bacteria closing off the taps. Are u using check valve spouts?

[Tater]

I would suspect bacteria. If you aren't extremely careful with your tapping technique, you can put bacteria in the tap hole. The tree "healing" means it's fighting the bacteria. My taps lasted 5-6 weeks, even with some temps in the 60s, 70s, and even 80. Some taps did dry up sooner than others, and I wonder if the small 2" pipe (with cap) holding my sap sack helps to limit airborne bacteria.

There may be other factors at play in your situation, such as some trees/sides may not be thawed out yet if they were frozen solid.

[Russell Lampron]

Are you using new or sterilized taps? If not the bacteria in the tap has caused the trees to start the healing process. My 24 buckets were tapped for 5 weeks and with new taps all but one of them was still running.

[Loon Lake Louie]

Thanks everyone for you thoughts on my question.
The taps I'm using aren't check valve type. They are, for the most part, new 1st time use. However they have been in an opened bag in the sugar shack all summer as I got them a year or 2 ago. I didn't do anything to sterilize them before use.
How should taps be prepared for use? Should the tap drill be sterilized before use as well? What is a tried method of sterilization?

[DrTimPerkins]

There are two separate processes going on. They are related, but not the same.

1. Taphole drying - this is induced by microbes in the taphole. The trees response is to "compartmentalize" the wound by placing metabolic byproducts into the tissues surrounding the wound to block off the entry of fungi and bacteria into the tree (where they could cause disease). In preventing these microbes from getting in, they also prevent sap from coming out. On open tapholes with buckets this can happen pretty quickly (weeks), especially if it is warm. In tubing systems, it takes considerably longer (a month or two). The better your taphole sanitation practices (new spouts or exceptionally well cleaned spouts), the slower the taphole drying process, although with open tapholes/buckets, the deck is stacked against you.

2. Taphole closure - this is the process where the tree grows new wood over the wound. Typically with small spouts (5/16" or thereabouts) it takes 1-2 yrs in a well-growing tree. With 7/16" spouts it may take 3-5 yrs. By the time taphole closure is occurring, the tapholes are no longer producing sap.

[Loon Lake Louie]

Thanks Dr Tim!!! I think I may be a candidate for the first scenario. I will finish this season and next year take extra care when preparing my taps and tap drill.