Sunday, 16 March 2014

Separating the bees from the honey using sweet almond oil - without success

Some things work and some don't. We think it's worthwhile sharing the failures as well as the successes if it helps others to avoid encountering the same problems. 

It was time to harvest honey from our hive.  Previously we'd separated the bees from the honey using a bee escape board which we posted about here. That worked really well. But, being scientists by training we're always happy to investigate further, so this time we thought we'd trial a different method.  We'd heard that using almond oil worked well so we thought we'd give that a go.

First off, it's important to note that there is more than one type of almond oil. The sweet almond tree (prunus dulcis, var. amygdalus) is the source of the almonds we eat. Sweet almond oil is derived from the kernel whereas pure almond oil is taken from the fruit. Then there is the bitter almond tree.  According to Wikipedia the bitter almond tree (prunus dulcis, var. amara) also produces an almond, but broader and shorter in shape, containing about 50% of the fixed oil that occurs in sweet almonds.  It also contains the enzyme emulsin which, in the presence of water acts on soluble glucosides, amygdalin and prunasin yielding glucose, cyanide, and the essential oil of bitter almonds, which is nearly pure benzaldehyde. Bitter almonds may yield from 4–9 mg of hydrogen cyanide per almond.

We were advised to use sweet almond oil, so that's what we did. Sweet almond oil is essentially odourless to humans and is used in cosmetics, hair care products, aromatherapy etc. It seemed like a fairly benign substance so we were happy to give it a go.  Bitter almond oil, on the other hand, sounded quite toxic and it wasn't something we'd ever consider putting in our hive.  

How is the almond oil method supposed to work? The oil is sprayed on a tea towel that is laid on top of the super you want to harvest. Bees do not like the smell of almond oil and will move away from it, vacating the box you want to harvest. Once the tea towel is removed the smell disperses out through the hive entrance.  It all sounded fair enough.
So now to the harvesting. The first step of honey harvesting is to make sure that you are leaving the bees enough honey to get on with things.  As responsible beekeepers we should only be harvesting excess honey, always leaving behind enough for the bees' needs. When we harvest our honey, rather than harvesting individual frames throughout the season, we like to harvest a whole box. We find it's easier for several reasons:
- you go through the entire harvesting process fewer times,
- you have less bees flying around when you are doing the actual harvesting because it's quicker to take the whole box than individual frames, 
- it's less messy as you aren't trying to brush bees off frames of honey. 
- also, ideally, you have few or no bees in the box when you take it inside to process - this is where separating the bees from the honey using a bee escape board comes in....or potentially using almond oil to do the same job.

Once we'd established that the box was okay to harvest we got a clean tea towel and our sweet almond oil. 

Sweet Almond Oil and a clean tea towel

Then we put a few blobs of almond oil on the tea towel.  We were told that you don't need to soak the tea towel with the oil. We couldn't smell it but supposed the bees could, and they wouldn't like it.

Putting a few blobs of sweet almond oil on the tea towel

 Lay the tea towel over the top of the frames.

Placing the tea towel directly on top of the frames

Now put the lid back on and walk away. Make sure there are no bees under the lid when you put it back on.

Lid goes back on and we come back in a couple of hours

The idea is that over the course of the next hour or so, any bees that were in the top box should move down into the hive, away from the smell of the oil.  Two or so hours later the bees should have completely exited the top box enabling you to remove it for processing.  The person who kindly told us about this method had only 1 bee left in the box after an hour. That was the kind of result we hoped to emulate. A quick look on the internet confirmed the success of this method. This site said the almond oil technique cleared a super in 5 minutes although it didn't specify what type of almond oil was used.

So how well did it work for us?  Unfortunately, it didn't work at all.

 An hour and a half later the box was still chock full of bees.  They didn't seem to care two hoots about the oil splattered tea towel.  Maybe we hadn't put enough sweet almond oil on the tea towel?  Maybe we needed to wait longer? Hoping that that was the case we removed the tea towel and re-applied the almond oil, this time much more generously. Back on with the lid and away we went......again. Four hours later with our fingers crossed we came back and had a look. Still no good. The box was still just as full of bees and they were actually crawling on the underside of the oil soaked tea towel. Obviously it hadn't had the anticipated effect.

From this spectacular lack of success it seems likely that sweet almond oil is not the type of almond oil people use for honey harvesting.....or if it is, then there was something wrong with the batch of oil we had. 

Our next step was to check with Mr Google for some answers.  From the research we did we found people who have used almond oil to assist in harvesting honey either:
- didn't specify what sort of almond oil they used (it was just referred to as 'almond oil'), or 
- indicated that oil of bitter almonds was used. 

As we mentioned above, oil of bitter almonds is nearly pure benzaldehyde - it has a strong odour and can burn your skin (not nice!) so as proponents of natural beekeeping there's no way we would use it in our hive - it just doesn't sit well with us. If bitter almond oil is the only type of almond oil that works then this method is definitely not for us, nor would we want to be seen as recommending it to others.  We had hoped that all almond oils would work. We were wrong.

If anyone knows more about using almond oil to harvest honey we'd love to hear from you. In the meantime we'll go back to using a bee escape board to separate the bees from the honey and use our sweet almond oil for making soap...but that's a subject for another post.

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