mesh Size

[dhempy]

Anyone have any idea what the equivalent mesh size of SS woven cloth would be to be comparable to fine mesh hop bags? I can tell you that 30x30 (0.02") is not fine enough and that 60x60 (0.009") is probably too fine.

Dan

[DrDually]

Dan
Try http://www.mcmaster.com for this info

[JonW]

I just sent a link to this message to member SamIam. He recently built an all SS hop spider and experimented with various SS mesh sizes. He might be able to give some feedback on this.

[dhempy]

Dan
Try http://www.mcmaster.com for this info

Been there got those ... what I need is what mesh size are hop bags (bags hold hop particulate better than my hop spider at 30x30 mesh does) so that I can get the equivalent SS mesh from McMaster.

Dan

[dhempy]

I just sent a link to this message to member SamIam. He recently built an all SS hop spider and experimented with various SS mesh sizes. He might be able to give some feedback on this.

Thanks ... I am curious as to what Sam found out.

Dan

[nevery]

People on homebrewtalk seemed to generally like 38x38 or 40x40 but I'd like to hear the results of Sam's experiences.

[SamIam]

Hi Dan, I’m not sure I’m going to be much help with providing you answers but here is what I have attempted. The first one I built wasn’t really a hops spider more like a curved panel essentially sectioning off part of my kettle where the pick-up tube is. It clipped to the top of my kettle and my pick-up tube at the bottom to hold in place and the curvature of it provided a spring like effect to seal against the sides. I skinned it using 30x30 SS mesh. In general, it worked pretty well but I was always worried about it becoming detached during a boil then I would be screwed. Also, if I used more than around 8oz of hops the 30x30 screen would plug so much that my pump would suck the section behind the screen dry and I would still have 10 gallons of wort on the other side the screen. So with that setup and the amount of surface area, I think the 30x30 screen was to fine.

On the next attempt I built an actual spider. I bought some SS baking sifters that have a fine mesh screen (attempted to count the mesh once and I think it’s about 50x50) and wrapped them with some 20x20 SS mesh. My thinking here was I didn’t want to plug the wort from draining out of the spider and still wanted to have good wort movement from the sides during the boil and the finer mesh would prevent the hops from falling through the bottom. The first time I used this was on a recipe that used 6oz of hops. It worked ok but it seems the 20x20 mesh around the sides is a little too course and I ended up losing about ½ the hops in the kettle.

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Currently, I use the setup in combination with the hop bags. It’s like a two stage filter now and works really well. I get good movement of the wort though the spider and I can even stir the hops around a bit hopefully improving utilization. I’d like to eventually move away from using the bags and find a solution that just uses the screen, but I haven’t had time to play around with it lately. With the spider having more surface area, I think I’ll try the 30x30 SS again next time.

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Lastly, I’ve come to the conclusion, (for some more experienced brewers I’m probably stating the obvious) is that you’re not going to prevent all the hops from entering the kettle. For me, it’s not a big deal because I whirlpool and let things settle a bit before I go into the fermenter so there is an certain level of hops in the kettle I can tolerate before I worry about plugging up the plate chiller. I think the more important answer is to try and find a good balance of filtering as much of the hops while still allowing the spider to drain out and still let them have good movement during the boil.

I’m guessing I probably created more questions than answers.

[nevery]

Thanks for sharing Sam. How much did all that SMS mesh cost?

[dhempy]

Thanks Sam:

I am thinking like you .. that the next time I brew I will use bags in my spider .. until I can find out what mesh to use. I can say that 30x30 is too coarse for what I'm looking for and I would bet that 60x60 will be too fine. The fellow that built my spider (commercially) is going to do some tests with 40x40 and 60x60 to see how they go. I am going to try to estimate hop bag mesh equivalent and also see if I can get some idea about the mesh on the Hop Stopper. Clogging versus filtering is a tight tradeoff I think so getting it right may result in some give and take.

Dan

[dhempy]

I just looked at a hop bag ... the mesh isn't square ... and my eyes aren't good enough to do an _EXACT_ count but my best guess is that it is something like 30x60 ... when you look at the bag itself, there are real fine threads in the mesh squares ... they kind of run triangularly but more so in one direction than the other ... I counted 1/8" each way and multiplied and did a smidge of rounding to get to 30x60. I've done some quick searching and there are SOME rectangular SS meshs available ... but I have yet to find a 30 x 60.

So If anyone has other places to try for SS mesh (I've already tried McMaster Carr), let me know!

Dan