I have not done this (might consider it though) but you can buy large packs of brown 'lunch bags' cheaply - if they are too big just trim them down. My grape clusters would fit in them nicely, I think.
How do they handle heavy rain, though? How were the bags secured onto the cluster of grapes in your reading?

I bagged a couple clusters last year just to try it and it worked great for keeping the yellow jackets off, but made more problems with earwigs. Dollar tree will has brown paper lunch bags for a buck. All I did was fold the end over the stem and stapled it shut, the bags held up ok in the rain. As long as the bags don't get moved around a lot they keep their shape and eventually dry out. In the end I didn't feel it was worth it, it is just easier for me to remove a few chewed up grapes from the cluster instead of bagging them.

What I also discovered is that the suggestion of 'waxed paper bags helps with rain. I think I'll give bagging grapes a try.

Before people started using ziplocks on apples, they used paper bags, stapling them as described.

We are using bags on our grapes this year as an experiment. Waxed lunch bags and organza bags. We put them on when grapes were small, about pea size. We used waxed lunch bags on Concord only and they were not so easy to put on. We ordered organza bags after and it was so much easier.
So far, bunches look great in their organza bags (moss green). We are going to try some this weekend. But paper bags are only on Concord and need to wait a bit longer.
The unbagged bunches we left for an experiment were gone as soon as they changed color. Birds, I guess
We will let you know a bit later how Concord in wax bags vs organza bags turned out.

We have about 100 bunches, wasn't difficult to bag them
Reliance on photo, ate them all already

Canadice, we will try this weekend

Tigkrit! Prettiest grapes in bags i've ever seen? Are the bags from MIchaels craft shop? Please let me know where I can buy them. They're going on the Concords tomorrow am.! Thanks a bunch, pun intended. Mrs. G

Just ordered the bags on line, they'll be here in four days. thanks so much Tigrikt.

I'm a big fan of the organza bag method. If you Google there are places that sell them in bulk for cheap, e.g. yourorganzabag.com.

This year I decided to put my bags on a couple days too late -- I went out with the bags and all I had was stems left.

Scott

Scott, that is the company I ordered from. Can't wait till they arrive. I bookmarked their site as I know I'll be back. Mrs. G

I believe we ordered from the side that Scott suggested above. 6x9.
It seems that bags added an additional protection against fungus. Not completely sure.

This is the 2nd year I've bagged grapes with ziplocks (corners cut off, just like for apples). The vines were left by the previous owners and I think they are Concords (but am not sure). Last year bagging (in late June) seemed to make a big difference with black rot. The bagged ones were fine until racoons ate them all in August, while the un-bagged ones rotted in early July.

This year I took care of the racoons, but it didn't make much difference. Both bagged and un-bagged rotted alike. Maybe un-bagged bunches were a bit worse, but it was almost a total loss anyway.

Last year I added a potted Mars vine, which is supposedly resistant to black rot. Based on what I saw, it is. The 2nd year plant produced 5-6 bunches of grapes with no sprays at all. They were tasty, not super sweet at 13.5 brix, but with an interesting flavor (a bit of muscadine). Of course, the location and that it is potted may have impacted the disease resistance (positively). Even so, I've attempted to top-work my Concord vines into Mars.

Left to right: Concord (un-bagged), Mars (un-bagged) Mars (bagged)

After reading this thread I tried bagging some of my grapes. I used the brown paper lunch bags you can pick up at the grocery store and just stapled them shut. Most of the bags stayed on the grape vine, even the bags I placed there back in June.

This was my first year with more than a bunch or two. The nicest bunches on top of the pile are bagged Mars grapes. My problem now is to figure out what to do with them all.

jtburton, those are excellent!!! I bet they smell good too. You better make up your mind before the fruitflies invade. They make excellent jam. And the best coffee cake! Mrs. G

Having never grown grapes before I didn't realize it but you are correct. I could smell the "grape" aroma from about 10ft away...it was amazing! Using the bags really helped me get some almost perfect bunches and I will try it again. Yes, it is a pain in the butt to put them on but it is like Christmas when I got to unwrap each one to see what was inside :-)

jtburton, the "Joy of Cooking" cookbook, has a fabulous recipe for 'grape pie', just made for these grapes. Far outpasses blueberry in flavor. (better becareful of the blueberry fans out there!) Make two and freeze one. Mrs. G

Thanks Mrs G, I'll look it up! Jeremy

I usually do not have bird issues with my grapes, but wasps
are a giant headache on my early varieties. Two years ago
I bagged some of my Canadice clusters with brown paper lunch bags. It was a lot of work stapling them on but it worked!

I did not put the bags on until early August since the wasps
don't bother the fruit until the sugar content gets high enough. The paper got rained on numerous times but dried and held well. One bunch was missed in picking and I found it in September. Over ripe but the paper was still holding up well.

I don't have to worry this year about the wasps as the previous cold winter killed my Canadice vines to the ground. Starting over from a root sucker from each vine. No fruit this year.

How do the organza bags protect the fruit from wasps? can they not feed on the fruit near the bag sides? or do you just try to keep the bag as open as possible so that the fruit isnt near the bag sides?

Dont recall we had any problems with wasps.

What size organza bags are good? With brown lunch paper bags, don't grape need light to grow and ripen? Thanks.

Thank you tigrikt. I also agree the colorful organza bags are prettier!

I've actually seen this technique with dates, coyotes and birds were eating them but they put sack with a hole in the bottom for the high ones because birds cannot eat in midair, and they covered the low ones entirely to prevent coyotes, this helped them ripen safely