After purchasing 8oz wide mouth mason jars specifically for cream Brule type deserts, I can’t get them submerged with the cream within. They float! I tried opening up the lid a bit more and the cream starts contaminating the water.
Any suggestions on technique?
Did you only fill them half full??? Never had that problem. I fill mine to about 1/8" below the thread of the jar.
(and not to nitpick) but it’s creme brûlée. 
Be VERY careful not to over-tighten the jars!!! Just “fingertip tight” - so the air can escape as the contents expand - otherwise they’ll blow the bottom off of your jars and your bath will be contaminated (and you’ll have to dump it out and reheat a new bath.)
(that’s happened a few times to me as well)
Fingertip right was leaking the cream. I screwed them tight and then back of 1/8 of the rotation…
So fill them right up to the thread eh?
Yep, you need them pretty full - just need to displace enough water to let them sink.
I just took them out and the Brule is all bubbly! I wonder what I am doing wrong… could it be the cream?
I am using Australian (coles) thickened cream. It’s the third time I am trying the same recipes and it’s always bubbled (the firs two times were in a Sous Vide bag. I thought since the bag inflated, there much have been steam inside the bag that curdled the eggs and cream. Hence the mason jars…but seems to be the same result…
Recipes I am following…
4 egg yokes
45g sugar
Pinch of salt
1tsp vanilla essence
300ml of thickened cream
Beat eggs, sugar, salt and essence and then slowly add cream and mix briefly and gently with a whisk.
Strained it through a sieve and poured with a funnel into the mason jars.
Briefly flamed top to eliminate any bubbles.
Placed into 85c for 1hr.
I make mine based on:
160g egg yolks = 11 yolks
90g sugar = 1/2 cup
3g salt = 1/2 tsp salt
600g Heavy cream = 2 1/2 cups = 625ml
1 hour at 80C / 176F
I think your batch might be a bit light on egg yolks, compared to what I normally do (which seems to be about twice the size of what you’re currently doing).
So,
I tried eating the ones I cooked earlier, and to my suprise it seems only the very top has a light layer of air of bubbles.
That is without doing the sugar caremelisation on top.
I will try it with sugar now and see whether the layer melts away.
Should the cream be totally bubble less when cooked? Do you see the top layer of air?
Did you get rid of the bubbles before you cast them into the jars? (or ensure there were no bubbles before you put them into the sous vide?)
Any bubbles that occur in the cooking process in the sous vide should dissipate during the cook.
I believe I have… I ran it through a fine sieve and also briefly flanked the top to eliminate bubbles, just in case.
There were less bubbles prior to cooking then after…
One of the instructions in the recipe I’ve always used is as follows:
Strain the mixture, then allow to rest for 20 to 30 minutes so that bubbles have time to rise to the top and dissipate.
Skim away any remaining bubbles
Did you let it rest after straining? If not, then this might be your answer!
If you’re beating the eggs and sugar together you’re incorporating air. If you’re straining the resultant custard you’re dissipating some of the air, but picking more up at the surface of the stream. Flaming the top only removes bubbles that have already made their way to the surface. @Mirozen is correct, the jars need to rest for a time to allow any trapped bubbles to make their way to the surface. This can be helped a little by giving the jars a bit of a tap on the bench (much like one does with cake batter once it has been poured into the tin) but the most successful way is to let them rise naturally.
So. Strain mixture into the jars. Let them rest at least half an hour. Then flame the surface to burst bubbles if there are any visible on the surface.
Just curious, what’s the problem with floating jars? I put a lid on the water tank to preserve temperature (and save energy) so the out of the water jar gets (air) heated too.
BTW, The physical way to remove bubbles would be to lower the pressure. Maybe a pressure cooker plus your vacuum cleaner can help.
I’m sure that, with a bit of thought, it would be possible to come up with something even more complicated than that.
Myself, I’d just put something heavy on top the jars.
The key to the floating issue is to fill the jar full enough. If the weight of the filled jar is greater than the volume of water it displaces the jar will sink, period. That volume of air at the top of the jar weighs practically nothing, so just replace it with a bit more of whatever you are cooking and you’ll sink those jars.
Just did another batch of Creme Brulee for a family get together - no floating issue with any of the 8 mason jars.
I found a recipe using exactly the ingredients you list.
I cook also for one hour but at 80°c and the results are perfect
I have small mason jars with clip down rubber sealed lids holding about 100ml each.
Also weck jars with a much larger capacity 290ml again with rubber seals on the lid and 4 clip on metal seals to each jar, bagged individually. Also sit on metal trivets to allow water to circulate all round the individually bagged vessel.
Did you heat the cream? It should be heated to just simmering, then strained, a little at a time through a strainer into the egg yokes, then whisked. Add a little more then whisk again until done.