Smoking Fish at Home Safely

PNW 238 • Reprinted May 1999 Smoking Fish at Home — Safely K.S. Hilderbrand, Jr.

Three common ingredients in all Strict attention to fish-smoking recipes are salt, both of these smoke, and heat. This publication requirements is points out that salt and heat are essential, for two important for safety, and it explains reasons: the basic techniques for preparing • It’s difficult to predict delicious smoked fish with absolute exactly how much salt a piece of use safety. It also recommends refriger- fish will absorb. good quality ated storage for all smoked fish. fish. Smoking will not Note that this publication applies • It’s difficult to determine after improve fish quality; in to fish heated during the smoking smoking whether the internal fact, it may cover up certain process. “Coldsmoked” fish (which temperature did indeed remain conditions that could create ° usually means fish kept below a at 160 F for the full 30 minutes. food safety problems later. range of 80 to 90°F) is a different Fish with a high oil content Thaw frozen fish in a cool product and is not discussed here. usually is the best for smoking. It place or in cool water. absorbs smoke faster and has Clean all fish thoroughly to better texture. On the West Coast, remove blood, slime, and harmful some of these species are shad, bacteria. Keep fish as cool as Smoked fish is good, sturgeon, smelt, herring, steel- possible at all times, but do not but… head, salmon, mackerel, sablefish, refreeze. When you cut fish for and tuna. You can smoke any fish, smoking, remember that uniformly Fish smoked without proper however, without fear of food sized pieces will help achieve salting and cooking can cause food poisoning if you observe some more uniform salt absorption poisoning—it can even be lethal. basic principles. You’ll find these without risk of over-salting. Do not Most food poisoning bacteria can principles in the fundamental let fish sit longer than 1 or 2 hours and will grow under the conditions steps of all fish-smoking recipes: after cleaning and before smoking. normally found in the preparation preparation, salting, smoking and and storage of smoked fish. cooking, and storage. Botulism is, of course, the most harmful of these bacteria. Salting There are two requirements for Salt is what preserves smoked the smoking of fish so that it will Preparation fish. Products with high moisture store safely with refrigeration content require more salt than (38°F): Different species of fish require “dry” products. ° different preparation techniques. • You must heat fish to 160 F Salmon usually are prepared by Without chemical analysis, it’s internal temperature and removing the backbone and hard to be certain that the fish has maintain this temperature at splitting. Bottom fish are filleted. absorbed adequate salt. That’s least 30 minutes. (See “Time– Small fish, such as herring and temperature requirements,” smelt, should be headed and page 4.) gutted before brining. (Columbia • You must salt or brine fish long River smelt traditionally have been Kenneth S. Hilderbrand, Jr., Exten- enough to ensure adequate salt smoked whole because they have sion Sea Grant seafood technologist, is present in the finished stopped feeding by the time they Oregon State University, in consulta- 1 product (greater than 3 ⁄2% are harvested.) tion with Extension specialists at the 1 water phase salt; see “3 ⁄2% In general, however, certain University of Idaho and Washington WPS” on page 4). principles apply in all cases. First, State University.

A Pacific Northwest Extension Publication Oregon • Idaho • Washington why proper cooking and refriger- ated storage are essential for absolute safety. However, some rules of thumb are useful to approximate the proper salt level. Salt the fish before smoking in a strong salt solution (brine). Salting in a brine that is 1 part table salt to 7 parts water by volume for 1 hour will do in most cases. For instance, 1 cup salt with 7 cups water will salt 2 or 3 pounds of fish. (This proportion will read approxi- mately 60° on the salometer scale.) About 30 minutes should do for a gutted herring. However, large or oily fish will require more time. Two hours for large chunks of a 30-pound salmon is a good starting place for experimenting. Figure 1.—Typical internal fish temperature during smoking cycle. Decrease the time for nonfat fish and for skinned fish. A final product that has a definite, but not Use a standard meat thermom- unpleasant, salt flavor probably Smoking and cooking eter to check the internal tempera- has absorbed enough salt. Cook the fish at 160°F internal ture of the largest piece in the Dry salting techniques are temperature for at least 30 min- smokehouse. This should ensure acceptable, and the same general ° utes at some time during the that all the fish has reached 160 F. rules apply. However, brining smoking “cycle.” This peak cook- (Some smokehouses may have should give more uniform salting ing temperature probably is the cool spots.) A long-stemmed dial than dry salting. most important part of any thermometer inserted into the fish Many recipes call for lower salt fish-smoking recipe—and one that through a hole in the smokehouse brine concentrations than the is often forgotten in home smoking. wall may be desirable; it allows 1 part table salt to 7 parts water Because you cannot determine temperature monitoring without formula given above—but for the final salt content (without opening the door. extended periods, 18 to 24 hours. chemical analysis), proper cooking It’s best to wait 3 to 5 hours These recipes may be sufficient, and adequate refrigeration are the before elevating the fish to the but they tend to offer more oppor- ° only way you can ensure a product 160 F+ internal temperature. This tunity for bacterial growth and safe from botulism. is easier to do after most of the possible spoilage later. In addition, A typical fish-smoking cycle moisture is gone, and there will be these procedures prolong the (see Figure 1) should bring the fish less tendency for a baked fish entire process and increase the to over 160°F internal temperature flavor. In addition, there will be mess you must clean up later. within 6 to 8 hours (internal—not less “curd” formation caused by Rinse and air dry all fish before oven—temperature). juices boiling out of the fish. smoking. This not only gives If your smokehouse cannot You can do further smoking and smoke a chance to deposit evenly provide 200 to 225°F oven tem- drying after the 30 minutes at over but also helps to prevent surface ° peratures, you’ll have to cook the 160 F. Keep the fish temperature spoilage during smoking. Smoke ° final product in your kitchen oven. above 140 F to prevent growth of will not deposit easily on a wet Waiting longer than 6 to 8 hours harmful bacteria. However, some surface. for that vital 30 minutes at over oily fish (such as sablefish) may If proper drying conditions are 160°F presents a danger of spoil- never “dry out” the way salmon or not available (cool, dry air), try age caused by bacteria growing tuna do. placing the fish in the smokehouse under ideal conditions (100 to Use only hardwood for making with low heat (80 to 90°F), no 130°F). smoke. Maple, oak, alder, hickory, smoke, and doors open. With a Remember: Smoke itself is not birch, and fruit woods are all good wood heat source, use a low, clean an effective preservative under fish-smoking woods. Wood from flame. most smokehouse conditions. conifers leaves an unpleasant taste on the fish. Do not use fir, spruce, pine, or cedar. Figure 2.—Basic components of a smokehouse. This drawing is not intended, nor should it be used, as a blueprint for building a smoke- house. It shows the features to look for in a smokehouse and their general arrangement. The key features are: (1) an independent Figure 2 illustrates the basic achieve the 30 minutes at over source of heat for the pot of wood components of a good smoke- 160°F internal temperature. chips or logs; (2) a controllable house. vent, or flue, at the top; (3) a A common question asked controllable draft at the bottom; and about fish smoking relates to the (4) some thermostatic control over small metal smokers readily Storage the oven temperature, connected to available in most hardware or Freeze or refrigerate your (5) another heat source to raise sporting goods stores. This smoked fish (below 38°F) if you do temperature in the smokehouse to equipment may be adequate, but it not plan to eat it immediately. This 200 to 225°F. has difficulty reaching tempera- is essential; the salt content is tures high enough for proper unknown, and there may be doubt cooking. So if you do use one of about the time and temperature these small devices, you may need achieved in the smoking cycle. to use your kitchen oven to You can retard mold growth on mum level of salt recommended by Time and temperature recommendations your smoked fish if you package it the U.S. Food and Drug Administra- are based on research conducted by Melvin in a porous material such as cloth tion for commercial products. W. Eklund, former director, Utilization or paper toweling. This prevents Although most home smokers Research Laboratory, National Marine “sweating,” a process in which don’t measure %WPS, it’s good to Fisheries Service, Seattle, Washington. moisture moves from the fish to keep in mind that a definite level of Pacific Northwest Extension publications the inside of the bag, causing a wet salt is required for safety and that are jointly produced by the three Pacific spot where mold can grow. This is adequate refrigeration is the only Northwest states—Oregon, Washington, and Idaho. Similar crops, climate, and especially severe if you place safeguard for those who cannot topography create a natural geographic warm, plastic-wrapped fish in a measure WPS. unit that crosses state lines. Since 1949 the refrigerator. PNW program has published more than 500 For extended storage (longer titles. Joint writing, editing, and production than 1 to 2 weeks), tightly wrap have prevented duplication of effort, For further information broadened the availability of faculty and freeze smoked fish. Little specialists, and substantially reduced the quality is lost in freezing smoked Most bookstores and sporting costs for participating states. fish because of its low moisture goods stores carry a variety of content. (For instructions on books on “smoke cooking.” Most Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, correct packaging for freezing, see have delicious recipes and clear 1914, by the Oregon State University Exten- Home Freezing of Seafood, EC instructions. These, plus the use of sion Service, Washington State University 1363.) common sense in following the Cooperative Extension, the University of principles outlined in this publica- Idaho Cooperative Extension System, and the U.S. Department of Agriculture tion, will ensure safe, pleasing, cooperating. home-smoked fish. Liquid smoke and The three participating Extension Services sodium nitrite recipes Related PNW publications offer educational programs, activities, and Fish Pickling for Home Use, materials—without regard to race, color, religion, sex, sexual orientation, national Liquid smoke and sodium nitrite PNW 183 are used in some home recipes. origin, age, marital status, disability, and Canning Seafood, PNW 194 disabled veteran or Vietnam-era veteran It’s recommended that you do not status—as required by Title VI of the Civil rely on them for product safety. Home Canning Smoked Fish, Rights Act of 1964, Title IX of the Education The only thing you can rely on is PNW 450 Amendments of 1972, and Section 504 of adequate refrigeration. the Rehabilitation Act of 1973. The Oregon State University Extension Service, To order, contact: Washington State University Cooperative Publication Orders Extension, and the University of Idaho Extension & Station Cooperative Extension System are Equal Time–temperature Communications Opportunity Employers. Revised October requirements Oregon State University 1991; reprinted May 1999. $1.00 422 Kerr Administration While regulations for commer- Corvallis, OR 97331-2119 cial fish smokers may permit a 541-737-2513 minimum temperature lower than 160°F (30 minutes), home smokers In Idaho: don’t have the continuous time– Ag Publications temperature recording equipment University of Idaho necessary to ensure proper Moscow, ID 83844-2240 cooking. 208-885-7982 Therefore, I continue to recom- mend 160°F (30 minutes) as the In Washington: minimum internal temperature for Bulletin Office home smokers. Cooperative Extension Cooper Publications Building Washington State University 1 3 ⁄2% WPS P.O. Box 645912 Pullman, WA 99164-5912 This phrase (“WPS” stands for 509-335-2857 “water phase salt”) means that the 1 salt content is 3 ⁄2% of the moisture left after smoking. It’s the mini-