Help needed for a pest issue - 'warehouse moth'

While i go about making friends with a bar manager for some access and help with using CO2, i wonder if anyone has maybe used an oxygen absorber pack instead?

Looks like the idea would be to store the beans in an airtight storage container, or a grain pro bag (as earlier mentioned) and put one of these oxygen absorber packs inside. This then supposedly absorbs all remaining oxygen. I assume this would take longer than using the CO2 method, but would it eventually have the same results without having to use CO2?

Alternatively i also read about creating an actual suction chamber, similar to those bag things that you store duvets in etc and then remove the air with a vacuum cleaner. Any thoughts on whether that method could also yield good results?

If it helps any, what I've been doing is using dry ice, about once per month.  I recieved a shipment of 10  50kg bags of cocoa in September and immediately propped the bags up in a tarp and duct taped the tarp up the sides so it was at least semi tight.  I have been calculating based on the size/volume of the bags, and only use about 2-3 oz of dry ice per bag. I simply place the dry ice on top of the bag, and then cover the entire thing up with a tarp.  I do this once a month in the warmer months and at least locally this costs approx $5US. I've yet to see an issue with moisture and have yet to see any insect activity in any of the beans i've sorted and roasted. 

I'll note, I've not done this procedure since Dec when we got our freezing temps and the storage area dropped to a pretty steady 40F/4C. Temps are now up in the 80's and the storage area is holding stead around 65F.  I'm out there to get beans to sort, roast, and process at least every other day if not daily.

Now, being totally honest, I'm not sure how effective this is, as the area i'm in I have a very hard time keeping the wolf spider and black widow population under control with monthly sprayings of pyrethren insecticide. So, either i've been effective with the dry ice or the spiders are fed  

[edit] something to note though, I live in a desert. So a 30% humidity is a high humidity day. Right now we're about 16%.[/edit]

Note: As far as will they attack beans or finished product, they may prefer beans but if you give them access to finished goods they WILL get to them. Guaranteed.

James,  As your in the UK, I think you will find CO2 in a cylinder easier to find than 'dry ice' (solid CO2 which needs to be stored at -70C) although note you can make slugs of solid CO2 from a cylinder that's fitted with a dip tube using a special draw off device that traps the liquid as it is flowing from the cylinder.... Don't know how expensive these are, it's years since I last used one in the laboratory.

 Suggest you get friendly with a local Pub owner and 'borrow' a cylinder of CO2 and the regulator,  pipe the gas into the bag at say 2 - 3 psi and allow it to 'escape' for a while, once you have flushed the air out of the bag, seal it up and cross fingers it will be good to go.   If you can't get a loaner,  welding supply firms can hook you up with CO2  (your want disteller's grade really - same as used to serve beer, some CO2  is a mix intended for welding only not food)  FYI: Firms like MachineMart sell cheap cylinder regulators and fittings..Again you need to reduce the pressure from the cylinder's  hundreds of pounds per sq inch to a 'gentle purging wiff'....  PLEASE NOTE BELOW

SAFETY:  Be sure to use a stand or chain the cylinder to the wall if it falls it can break off the top and turn into a lethal heavy weapon.   CO2 is an asphyxiant in a closed space and will displace the breathable air, use only in a well ventilated space.    The UK H&S regs may even require a  gas monitor to be installed in a space that contains gassed up bags?     Please use prudence and common sense.

Mark

Sorry i posted that before properly reading Jordans earlier post.

I will contact my main supplier in Nicaragua and see if they can sort out some of these grainpro bags as they sound like a step in the right direction.

Also i will look into getting the one that CO2 can be used with for treating my current stock of cocoa beans and give it a test.

Will report back with my findings.

Some brilliant suggestions here, and I am glad it has created a discussion about an issue that will unfortunately likely affect us all at some point, and perhaps a topic which producers don't like to discuss in the open (just from my experience in trying to find info on these moths). 

This is the first I have heard of the grain-pro bags, and they sound great. But like Sebastian I too would be concerned about high moisture trapped in the sealed bag, and essentially 'sweating' in warmer high humidity environments.

I unfortunately do not have access to a large cool room in which to store my beans and so stop the hatching of the eggs. Mine are stored in my workshop and the temp can range anywhere from 10-25 degrees centigrade depending on our unreliable british weather. So I am certainly interested in any other way to prevent or combat a moth infestation. 

So far the CO2 method seems most efficient and organic, but what's the safest way to go about treating the beans in this way?

I'm a skeptic by nature (aren't all scientists?) - sounds like there's an excellent opportunity here to do some controlled tests on a lot of beans, mix them up, ship half in GP bags, and the other half conventionally.  Toss in some data loggers, and count what crawls out of each test.  

Lots of enterprising small batch folks here who are ordering beans. I'll help you construct the study.  Who wants to do a ship test in the name of science!  One caveat is the beans would need to disembark from a port such that the transit carries it across the equator, preferrably during winter in the northern hemisphere.

Hello Jordan.

I was about to post a question for Sebastain regarding the 'industry view' of optimal moisture content for fermented raw cacao shipments prior to transit, but it looks like you have answered it?  What's high moisture content in this context?    Of course it's easy to check the moisture content of dried beans before they are sealed up, but doesn't the relative humidity (typically hot and steamy in Cacao growing areas...) have a greater contribution to the water vapour within the enclosure?  Surely it's largely this water vapour from the air spaces around the beans which might condense and or allow mold to develop, hence Sebastain's concern?   Is there an extra step to filling and sealing these sacks, i.e. something like doing it in a low relative humidity space?

The zipper bags do sound like a good way for us small craft scale chocolate makers to protect our warehouse stock, particularly in shared space where other clients aren't organic and are exposing their wares to chemical fumigation, other pest control chemicals or storing sacks of onions next to the cacao as you point out.

Mark

Thanks, Sebastian.  I understand your skepticism.  First, you're right: the GrainPro bag cannot have any holes in it for hermetic to work properly. However, I haven't found this to be a major issue.  The hermetic liner goes inside a traditional jute or polypropylene bag, which serves as a protective barrier.  Hooks are the biggest threat - at the port - but we have a sticker that says "NO HOOKS" to place on the outside of the jute bag.  It's important for the cacao grower/exporter - and the laborers who stuff the containers - to be properly trained (ie DON'T USE HOOKS!). (The Green Room is a specialty coffee warehouse in south Seatle that does not use hooks in off-loading containers.  It's a beautiful sight.)  

The specialty coffee sector widely uses hermetic and holes/damage have not been a major issue.   The other key, to your question, is storing hermetically at the correct moisture content, ie 6-7%.  High MC cacao should not be stored/shipped hermetically.  For shipping, I recommend the twist-n-tie bag.  For simple warehouse storage, the zipper bag is easy to use.  Infestation is a major issue for cocoa along the entire supply chain and we simply are over-fumigating, over-fogging and over-treating with chemical pesticides when we generally don't need to.  (This is true in the coffee and grain sector, as well).   I can design a study with you, if you want to try it yourself. There's also a number of current cacao exporters/chocolate makers (with whom I can put you in contact) who can share their own experience using hermetic.   And, again, as a reminder, for infestation control, hermetic is most effective at 20 degrees celsius and above (which is always the temp at origin)...

Thanks Jordan.  I admit i'm still skeptical simply due to kinetics.  I understand the concept.  The biomass of infestation is always going to be very low on a % basis, and the metabolic oxidative draw down rate due to respiration from larvae is incredibly small, and is further predicated on no holes in the material - which is difficult to guarantee at origin. Eggs wil be even lower.   Flushing with CO2 will certainly help displace the resident oxygen.  I'd love to have some controlled experimental data to review (or better yet have conducted it myself - it's just the way i'm built). I'd worry about condensation in the bag as there's no place for the moisture to go if it's sealed that tightly, leading to mold. I'm probably most skeptical as i've been doing this for a very long time at a huge scale, and have never seen it.  That's certainly not to say i've seen everything, and i always love finding new ways of doing things - but at first blush i do remain skeptical.

Prove me wrong so i can learn!

Hello Jordan,

Thanks for the very useful clarification regarding the use of GrainPro bags to both protect and treat cacao.  I'd planned to use 32 gallon bins for bulk storage, (bug and mouse proof) guess I'll need to contact you to explore using the GrainPro 69KG sacks /cocoon.   

Given the cost of 1/2 MT of single origin cacao it sounds like a very worthwhile investment, organic / fairtrade and then bombed with chemicals doesn't really cut it on the marketing front!

However, as CO2 is the primary greenhouse gas accounting for around 80% of the United States greenhouse emissions don't think I'm going to mention its use either.  Guess I could plant a tree for everytime I gas up a bag to offset?

Sebastian, thanks for your thoughtful responses to the above - and a clarification on GrainPro bags.  With infested cocoa, in a high temperature/high humidity environment, GrainPro's hermetic bags WILL kill the insects through suffocation.  This is how it works:  the insects (and the cocoa) respire, emitting carbon dioxide, and taking in the oxygen. Once the O2 level drops below 3%, all insects die. In other words, the hermetic GrainPro bag creates a "Modified Atmosphere" - low O2, high CO2 - which is lethal to insects (and all life). Depending on the level of infestation (which serves as the "engine"), the temperature and the humidity - a 100% insect kill can take from 1-2 weeks in a 69 KG GrainPro SuperGrainbag (SGB).  It's critical not to open the SGB (allowing more oxgyen in) during this time. 

In a colder, more temperate environment, where insect activity is reduced, there is a NON-CHEMICAL way to fumigate cocoa: Flushing with CO2 (a naturally ocurring gas). Here's how:  use a GrainPro Cocoon GHF or GrainPro Cocoon Indoor (see GrainPro website), both of which come equipped with an inlet port to enable flushing with liquid CO2.   This is an organic method of infestation control - not requiring chemical pesticides.  This CO2 flushing method vastly speeds up the insect kill - and works in temperate climates/cold warehouses.

Finally, to James initial question/issue, James should request his cocoa beans in hermetic GrainPro 69KG SuperGrainbags FROM ORIGIN (ie, Venezuela), to protect the beans in shipment, stop cross-contamination (onions, ayone?) or cross-infestation - and kill off any insects that might already be in the bag (or container) during the multi-week shipment from Venezuela to US ports.   This is the only way to control infestation without using an of the chemical 'ides...

Hope this helps.

Touche, pussy cat!

Sebastian, You are correct, I'm a poor typist and proof reader Methyl bromide not bromine.  You are however not quite on with phosphene.....

A phosphene is an optical phenomenon in which people think they see light when no light is actually entering the eye.

The fumigant is phosphine according to the FAO manual ( http://www.fao.org/docrep/x5042e/x5042E0a.htm) "Phosphine or hydrogen phosphide (PH 3 ) is a low molecular weight, low boiling point compound that diffuses rapidly and penetrates deeply into materials, such as large bulks of grain or tightly packed materials. The gas is produced from formulations of metallic phosphides (usually aluminium or magnesium phosphide) that contain additional materials for regulating release of the gas." 

According to the cocoa brokers I've spoken with something called ECO2FUME made by Cytec is used at warehouses in the USA, it's 2% Phosphine and 98% Carbon dioxide  http://www.cytec.com/sites/default/files/files/ECO_SPEC_SHEET_2-16-11_FINAL.pdf.   I agree nasty stuff, but rapidly disappears once the tenting is removed.   I share space with a craft distiller on a light industrial park, their 'pest man' would use it if they had problems in their grain store, but you do have to be licenced to buy it and apply it.

The Grainpro bags are as you say just another way to prevent warehouse infestation / and or protect fumigated goods in store or transit.

Yikes, methyl bromide (not bromine) and phosphene are both restricted use due to excessive human danger pesticides.  I can not recommend their use...

Industrial microwaves or Cobolt-60 irridiation would certainly work; however are not in practice utilized due to cost, consumer perception challenges, and flavor issues.

GrainPro barriers won't mitigate the problem, it literally puts a bag around it to try to contain it.  You could fumigate inside of the bag as a kill step, but utilizing the bag on it's own won't result in a kill, only a containment.

Warehouse moth:  CO2 and barrier solutions

Methyl Bromine used to be employed to fumigate commercially traded cocoa imports at export or receiving warehouses.  Banned / withdrawn since 2010 often replaced by phosphine which is highly flammable and rather nasty.  Typically in the warehouse they tent the pallets and gas the bags, interestingly phosphine is available in a form where it is mixed with carbon dioxide.   I imagine this is both to make a readily applied gas mix and of course the CO2 reduces the fire risk! 

Modified atmosphere storage works and certain hot or cold treatments also work. There have even been experiments with microwaving. (perhaps Sebastian can provide industrial insights regarding this?)    A small amount dry ice in a dustbin (UK!) or trashcan (USA) for a 1/2 sack works  well according to John (The Chocolate  Alchemist).  If you're handy and a practical sort, (making craft chocolate this typically is the case)  assembling a flushing system with a cylinder of CO2 from a welding gas supplier or a friendly bar owner could work if you can't readily get solid carbon dioxide (dry ice).    The usual  safety  / hazard notes about enclosed spaces and pressurized containers..(Attempt at you own risk, I'm not recommending you do it.)     Of course also consider, you don't need to pressurize just displace all the 'regular' air and replace and hold with CO2 for a bit, even relatively inactive insect pupae need oxygen to survive.....

 FYI:  Physical barrier solutions
 At the recent FCIA meeting in San Francisco,  in the queue for evening beverages I met a nice chap (Jordan) from a company called GrainPro  (Google it) , they make / sell special barrier solutions for farmers / cacao producers to protect warehouse stock and even individual sacks of cacao or shipping containers loads.   These sorts of protection might be a way to protect your stocks and they appear to have solutions that are highly scalable.

using dry ice is an attempt to modify the atmosphere - dry ice is carbon dioxide, and it sublimates (goes straight from solid to gas without a liquid phase).  the thought is that you can use it to displace the oxygen in the atmosphere, and suffocate the critters.  it will work if you contain it. personally i think it's the path of most resistance - it's expensive, condensation will be an issue, and you need to keep it tightly sealed once the atmosphere is modified (but not before, if you seal it tightly before you'll end up with a bomb).  it would very much surprise me if bay leaves and vinegar did anything helpful.  Cool and dry with spot fumigation as needed is the best option, in my opinion.

Remember to quickly discard your winnowed shell as well - the eggs are 90% on the surface of the shell, if you let your shell lay around in a warm room, they'll be quite happy to hatch the larvae there vs on the full bean in storage as well.

Cheers Sebastian, its good to actually get advice on preventions as the Rentokil bloke was helpful in telling me how to chuck everything and cleanse the room, but not very good at saying how to prevent future attacks. The room generally is quite cold, although i dont actually have access to a walk in refrigerator which would be handy. We had an unusually hot and humid late autumn/beginning of winter this year unfortunately so i dont think that has helped. Researched some preventions yesterday and the pheremone traps sound like a great idea, also perhaps oddly, bay leaves dotted around and a tub of vinegar is a good prevention...who knew.

I also saw on chocolate alchemy that dry ice is a good thing to use to kill of anything living within the beans when they arrive. Have you used this method?

Cold and dry is the best storage.  I find 60F or below and 50% RH is a nice target.  Tarp and fumigate if you're seeing signs of activity.  You can also consider pheremone traps if you're getting fliers emerging.

Hi thanks guys for your advice, its reasurring to know that its not just me and these beans that have had this problem. Sebastian, you mentioned they will always eventually occur if improperly stored, how best would you recommend storing the cocoa beans in order to minimise the chances of these moths taking hold? Currently i store them inside and have a UV fly zapper which helps, but i wondered if there were better precautions to make.

I have just discussed concerns i had with Rentokil (hope these answers can help others):

1)are they poisonous/dangerous to health - No, but like any living organism there is always the chance of bacteria being transferred

2) Do they just attack cocoa or attack finished chocolate also - predominantly they will only attack cocoa beans as that is their prefferred food source

3) What do the eggs look like - white/creamy, but also tiny, will only see them through a microscope

4) Can you safely fumigate the coca beans leaving them safe to use - Yes but the process is very expensive, starting at £3,000. So need to outweigh the cost of destroying beans, fumigating the room (normal non-food safe approx £400) and starting fresh, against using food safe fumigation (£3,000) which leaves the beans safe to use.

5) Once fumigated whats the risk of return - always a risk, moths are very common problem although not many want to admit to having it for obvious reasons, but everyone will likely have a problem with the moths at some point when dealing with cocoa beans.

Any more advice and experience to this thread would be great as i think its a problem that might not be discussed enough, but a problem that it seems is inevitable.

Yes.  Use a fogger, tent/tarp your pallets to maximize contact / exposure time, and place your fogger under said tent.  anything that ends in 'cide (pesticide, insectide, etc) i don't think i'd characterize as harmless to humans, so don't go looking for opportunties to breath it in or take a bath in it.   It's very commonly used as part of routine pest management cycles, and will be most effective if you're storing in bulk to use on a regular basis (ie don't wait until you've got a room full of moths to begin treating).

Sebastian - Do you have any experience or opinions using permethrin spray to control and combat cocoa moths? It's available commercially in quantity, not too expensive, and appears to be harmless to humans and lethal to moths and larvae of not only cocoa moths but other insect pests.

They're cocoa moths.   Preetty soon they'll be flying everywhere.  They're on all cocoa beans, from every origin.  

Keep your beans in a cool and dry place and the eggs won't hatch.  If you need to fumigate, that's also done regularly in cocoa warehouses all around the world.  

It is impossible to order beans from anywhere in the world that will not have an infestation issue over time, if improperly stored.  Anyone who tells you otherwise is lying or inexperienced.

Hi everyone,

not sure how common this is as i cant find much information about it. Basically i got a small sample of cocoa beans from venezuela, didn't get around to trying them out for several months, but i just came to trial them out and found a weird bug/lavae type thing on the inside of the sack, at first i thought it might be just a random bug as i have never come across it before, however i roasted a batch 130 centigrade for about 15mins. But cracked open a bean to test the nib flavour and found another lavae inside it. I did a bit of research and found that it could be the 'warehouse moth'. But no information on how to go about getting rid of it.

Has anyone else had a similar issue, or heard of these pests? and what can be done to either get rid of them? or what process do you undertake to sort out beans with potential bugs against safe beans?

major help needed as concerned about ordering any large amount, from what is otherwise a very nice flavoured bean.

thanks

James