Anonymous Modernist 799

thanks, Judy. I was going by the recipe that was in the hand-out from Max at the demo. Too bad about the errata - grrr... Oh well, all that was really lost were about $1.50 worth of carrots and a half-hour scrubbing out the scorch. I will definitely try this recipe again - it really was a knock-out flavour. Thanksgiving menu is a bit up in the air, as one of the guests has just spent the past weekend in hospital with bleeding ulcers - I suspect he'll be reduced to eating cranberry jello and turkey broth, poor soul! Otherwise, the only definite must-haves on the menu is this carrot soup (either with toasted coconut, or maybe savoury popcorn - haven't decided which) and a pumpkin cheesecake.

We were at Maxim's Sur la Table demo on Modernist Cuisine at home last week, and enjoyed the evening thoroughly. For me, one of the highlights was the very simple, but very scrumptious carrot soup, made in a pressure cooker. So for dinner tonight, I thought I would attempt to replicate that soup. What could go wrong? Carrots, butter, baking soda, salt, and a pressure cooker -- all things I have on hand. I followed instructions to the letter, painstakingly cutting out the core from about 30 tender new carrots, ensuring that I actually ended up with 500 grams of carrots, weighing butter, salt, baking soda, then plopping everything into our pressure cooker. Husband and I both wondered at the lack of water in the recipe, but thought that, since it wasn't called for in the ingredients, we wouldn't add any. So then we ramped up the PC to the recommended 15 PSI, and set the timer for 50 minutes, as per the instructions. At about 30 minutes, the carrots were smelling wonderfully sweet and caramelly. At about 35 minutes, there was a whiff of scorch in the air. By 40 minutes, I knew things were hopeless, but persevered. At 50 minutes, we opened all the windows and turned the fan on high, then scraped out bits of carroty charcoal from the PC, before putting it into hot soapy water to soak for a day or two, and went to plan B, and defrosted some lovely tomato bisque we made earlier this week. What went wrong? My strong suspicion is that 50 minutes cooking time is just too long. If so, perhaps the recipe should be amended. Or maybe we should have gone ahead and added some water at the start. If so, how much? I really, really liked this soup, and would dearly like to be able to make it for Thanksgiving dinner next week.

Chris said: Okay, now I'm really confused. What does acidity have to do with conductivity? One is a function of pH, the other of heat transfer. What we needed to know, and what the book does not make clear is the the amount of time for heat to transfer to a bunch of tomatoes. (And yes, I appreciate that you did answer that question in your response). Perhaps a more complete explanation of what constitutes a conductive food in the book would have been helpful. Or perhaps our reading comprehension is faulty. In either event, we have learned that 10 minutes at Bar 15 is ample processing time for a liter jar of tomatoes, and since tomatoes are currently cheap at our green grocers, no great harm done.

Thanks, Judy. Here we go, then:

Chris, thank you for your response. I fully agree that 10 to 15 minutes is a much more reasonable processing time. We followed instructions as precisely as we could, going so far as to ascertain the recommended 1" headroom with a ruler. If we did overfill the jars, it must have been with water. Other canning manuals advise that 20 lbs of tomatoes should yield about seven litres. In fact, we ended up with 10 one-litre jars. In the second batch of tomatoes that we canned, 20 lbs did fill just slightly more than seven jars. (These we processed for 40 minutes - still too long, and still some evidence of leakage, but the results were noticeably better). As per Vol. 2, page 88, we assumed that tomatoes packed in water fell under the "conductive" category, so used the sterilization time as per the chart on page 89. Hence, 94 minutes. Even if we had opted for the "convecting" category, the processing time would still have been 40 minutes - a far cry from 10 to 15 minutes. I have checked all the seals quite thoroughly, and so far all seem to be sound, so I have stored the tomatoes in our pantry. I will double-check any seals before use.Meanwhile, I'll be canning another case lot of tomatoes this afternoon, and will probably process them at 15 lb. for 15 minutes. I'd be happy to add photos of this disaster, but don't know how to attach them in this forum. Instructions, anyone? Again, thanks so much for your response.

Okay, so yesterday my husband and I spent a fruitful afternoon canning tomatoes and learning the ropes (so to speak)of pressure canning. Now we're wondering, what did we do wrong, and did we just waste 20 lb. of plum tomatoes? Here's what we did: We packed raw tomatoes into one-litre jars, added the recommended amount of lemon juice, filled the jars with boiling water, sealed them, then processed them for 1.5 hr. I think that's an extraordinarily long processing time, but according to Modernist Cuisine, it's a fail-safe to ensure that everything reaches optimal temperature for killing any possible toxins. The instruction book that came with our pressure canner recommends 10 minutes at 10 lb. pressure. Here's what we got: Bottles are only about 3/4 full, and there's evidence of leakage into the canner. After they came out of the pressure canner, the tomatoes were floating near the top of the jars, but have since settled to the bottom. The liquid and tomatoes fill only about 3/4 of the jars. They've also discoloured, indicating, to me at least, that they're seriously overcooked. Okay, so I know that we didn't pack the tomatoes tightly enough. I have another case of tomatoes to can today, so will address that problem. What I need to know is, are the ones we've already canned safe to eat? Or is the air space likely to harbour any nasties, and should we just discard them?